Browse Topic: Suspension systems

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Prediction of Trimmed BIW Noise transfer function based on BIW response using Machine Learning2026-26-0640To be published on 01/16/2026
This research focuses on the prediction of the Noise Transfer Function (NTF) in a trimmed Body-in-White (BIW) structure by leveraging machine learning technique considering BIW-level NTF, dynamic stiffness at engine mount attachment points, and Vibration Transfer Function (VTF). The study employs an iterative methodology, adjusting the thickness of various BIW panels to analyse their impact on noise transfer characteristics. Frequency response functions are generated at the BIW attachment points to assess the effectiveness of these modifications. By systematically increasing and decreasing panel thicknesses, and stiffness at the attachment point and trimmed BIW level responses the study aims to optimize the acoustic performance of the BIW structure. The findings provide critical insights into the relationship between structural modifications and noise transfer, offering valuable guidance for automotive design and engineering during early design stage to reduce the development time.
Kulkarni, Prasad Ramesh, Bijwe, Vilas, Kulkarni, Shirish, Sahu, Dilip, Inamdar, Pushpak
Systematic Study To Understand And Resolve Brake Pull In Commercial Vehicles Using Simulation And Proving Ground Tests2026-26-0083To be published on 01/16/2026
In traditional commercial vehicles with leaf spring suspension and Recirculating Ball Joint (RCBT) steering systems often experience undesirable pulling due to unsymmetrical steering mechanism during braking, especially when the suspension and steering hardpoints are not properly tuned. This study investigates the causes behind such pulling behavior, specifically focusing on brake steer and bump steer, which occur due to misalignments in the suspension and steering geometries. Brake steer happens when the braking forces generate a torque, causing the vehicle to pull towards one side. On the other hand, bump steer refers to the unwanted changes in the wheel alignment when the suspension undergoes travel, leading to instability or unintended steering input. These two phenomena, if not controlled, can result in undesirable vehicle handling, especially under heavy braking conditions. The study aims to understand and quantify these mechanisms, providing insights into how they can be
Pandhare, Vinay Ramakant, M, Anantha Padmnabhan, NIZAMPATNAM, BALARAMAKRISHNA, Londhe, Abhijit, Doundkar, Vikas
Sound quality refinement and vibration reduction during Horn Application in Electric Vehicles2026-26-0338To be published on 01/16/2026
This paper focuses on the cabin sound quality refinement and the tactile vibration reduction during horn application in the electric vehicle. Horn cracking sound is perceived in the cabin while pressing the horn. Higher vibrations are also perceived in accelerator pedal during the particular event. Sound diagnosis is carried out to identify the frequencies contributing to cracking noise. Transfer path analysis is conducted to identify the nature of noise and the predominant path through which forces transfer. Based on finding from TPA, various recommendations are evaluated which reduced the noise to a certain extent. Operational Deflection Shape(ODS) is conducted on the horn, horn mounting bracket and on the body to identify the component having higher deflection at the problematic frequencies . Based on the outcome of ODS, recommendations like dynamic stiffness improvement on the horn bracket and the body is assessed and the effect of each outcome is discussed. With all the
S, Nataraja Moorthy
Failure Analysis of Dissimilar Metal Weld Joint of an Air Spring Bracket within an Automotive Active Seat Suspension System2026-26-0487To be published on 01/16/2026
In modern four-wheelers, seat suspension systems play a crucial role in enhancing occupant comfort by mitigating the effects of road unevenness and vibrations. Among these systems, active suspension mechanisms offer advanced performance through complex assemblies involving welded, riveted, and bolted joints. This study investigates the failure of an air spring bracket - a critical component of a pneumatic active suspension system - manufactured by Gas Metal Arc Welding (GMAW) of two dissimilar ferrous materials which are likely to be SAPH440 and S355J2. These different materials were used based on mechanical properties required to perform by their particular part. System level validation tests were conducted to ensure the reliability of the seat suspension system. The one of the validation tests is continuous cyclic fatigue test which is carried out on the complete seat assembly. However, during vibration / cyclic endurance testing, premature failures were observed near the weld joints
Patale Jr, Reshma, PINJARI, JAYANT NAMDEV, BALI, SHIRISH
"Design and process Optimization of Suspension Components Under RWUP-based Loading Conditions"2026-26-0514To be published on 01/16/2026
Title: Challenges faced during design and manufacturing of POM (Polyoxymethylene) ring in Macpherson strut suspension. Abstract: Designing and manufacturing a POM (Polyoxymethylene) ring for a MacPherson strut suspension system brings a unique set of challenges due to the high-performance and durability demands for Indian road application. POM ring along with bump used in the shock absorber is designed to absorb the strong shock coming from the road inputs when suspension travel reached to the maximum limit there by absorbing the impact energy and preventing it from transferring it to the body. A bump stopper for a suspension of a vehicle is made of poly urethane (PU) and POM ring (Polyoxymethylene). The bump stopper forms of a bellows shape during the absorption of impact energy. Bellow or wrinkle in which concaves and convexes are repeated is formed on the outer surface of the bump stopper. POM ring is placed in the concaves of bump stopper which will define load, deflection
Koritala, Ashok Kumar, Malekar, Amit, kulkarni, Purushottam, S, SIVASHANKAR, Mishra, Harshit, Ganesh, Mohan Selvakumar, Patnala, Avinash, J, Ramkumar, NAYAK, Bhargav, M, Sudhan
Investigation and Reduction of Road Noise due to transient road inputs in Electric Vehicle2026-26-0358To be published on 01/16/2026
Higher road noise is perceived in the cabin when the test vehicle encounters road irregularities like bump or pothole in the public roads. The sudden transfer of transient road inputs inside the body caused objectionable cabin noise. Measurements are conducted on the test track at different road surfaces to identify the patch where the objective data well correlated with the noise measured at the public road. Wavelet analysis is carried out to identify the frequency zones since the events are transient in nature. Transfer Path Analysis (TPA) is conducted in both time domain and frequency domain to identify the nature of the noise and the limitation in each of the methodologies are explained. The dominant path through which the transient road forces are transferring inside the body are also identified. Based on the outcome of TPA, various countermeasures like reduction of dynamic stiffness of suspension and cradle bushes , structural modifications on the path are proposed to reduce the
S, Nataraja Moorthy
Novel Approach for Predicting Steering Rack Load Using Multibody Simulation2026-26-0378To be published on 01/16/2026
In the initial stages of a vehicle development program, the sizing of various components is a critical deliverable. The steering system, in particular, requires a precise estimation of the rack load for the appropriate sizing of the rack and assist units. Accurately predicting the load on the system during the early stages of development is challenging, especially in the absence of benchmark or legacy data. Commonly used processes for estimating parking steering effort often employ simplistic approaches that may fail to account for parameters such as tire size, vertical stiffness, and steering geometry, leading to reduced accuracy. This paper introduces an advanced methodology for predicting steering rack loads, which incorporates considerations such as contact patch size and pressure variation, as well as the tire jacking effect. The methodology involves mathematical modeling of the contact patch using mesh-grids, utilizing common inputs available in the early stages of vehicle
Shirke, Umesh, Dabholkar, Aniruddh, bardia, Vivek, Srivastava, Harshit, PRASAD, TEJ PRATAP
Optimizing Suspension Joint Reliability: Overcoming Bolt Loosening and Torque Variability in Automotive Production2026-26-0492To be published on 01/16/2026
In modern automotive manufacturing, ensuring the integrity of suspension joints under real-world driving conditions is a critical aspect of vehicle safety and performance. These joints endure substantial transverse loads and large vibrations due to irregular road surfaces, dynamic manoeuvres, and varying environmental factors. As a result, bolt loosening becomes a significant concern, compromising joint integrity and overall vehicle reliability. This paper delves into the challenges associated with maintaining joint integrity, specifically focusing on pre-load determination, torque application, and production-related issues. The pre-load generated during torquing is the primary factor that ensures a suspension joint remains securely fastened under dynamic road conditions. This pre-load is derived using road load data acquisition (RLDA) inputs, which capture the forces acting on the joint during actual driving scenarios. RLDA inputs provide critical insights into the forces experienced
Kumar, Sabeesh, Vasant Kumar, Jesse Daniel, Mishra, Harshit, Senthil Raja, T, NAYAK, Bhargav, M, Sudhan, NAMANI, Prasad, Vibhute, Shekhar
Brake Judder Resolution through Experimental Testing2026-26-0587To be published on 01/16/2026
Brake judder is a critical concern in modern automotive systems, impacting both vehicle performance and passenger comfort. This phenomenon manifests as undesirable vibrations during braking, often caused by various factors such as vehicle architecture, different wheelbase, brake design considerations, load distribution, suspension characteristics etc. These vibrations not only compromise braking efficiency but also affect the overall driving experience, making it a priority issue for automotive engineers and researchers. This paper investigates the root causes of brake judder in a M3 Bus category vehicle having pneumatic brake system, focusing on its mechanical aspects and operational dynamics. By employing a combination of experimental testing and analytical evaluations, the study delves into the influence of brake torque generation and its consumption during vehicle deceleration for different wheelbase vehicles having similar brake system, revealing discrepancies that contribute to
Mundkar, Rameshwar, Shete, Rahul, Nayak, Nihar, Gavade, Sarjerao
Analysis of door seal compression and its influence on NVH performance in heavy-duty vehicle2026-26-0339To be published on 01/16/2026
Seals in a truck cabin is one of the major contributors for cabin noise in terms of structure borne as well as air borne noise transfer path. This study emphasizes on the effect of door seal compression prediction and its impact on structure borne NVH in trucks. Vibrations are regarded as quality criteria in the perception of customers. It is necessary to ascertain the contribution of seal stiffness on compression of the seal under closed condition of the door rather than uncompressed conditions. The dynamic stiffness of door seal is calculated by non-linear analysis. The simulations models are constructed using the Mooney - Rivlin theory for both 2D and 3D seals. This encompasses contemplating the relevant seal mounted boundary condition on the body and the door of the vehicle. The stiffness after compression of seal is extracted from this non-linear analysis which is further used to obtain the vibration modes for the doors in the truck cabin. Subsequently, the compressed seal
L, Kavya, Ramanathan, Vijay
Data-Driven Prediction of Damper durability Cycles Using AIML Techniques2026-26-0550To be published on 01/16/2026
The suspension dampers play a pivotal role in controlling suspension dynamics, especially during rapid suspension movements such as pothole impacts, speed bumps, and off-road conditions. The dampers directly influence the ride comfort, vehicle stability. Ensuring the durability of these valves is essential to maintain consistent performance throughout the vehicle's lifecycle. To validate the valve configuration at high speed, in current development practices, durability cycles are typically derived through physical data collection on actual vehicle driven on proven ground tracks. While this method provides accurate real world validation, it is highly time consuming and resource intensive. The dependency on full vehicle testing also limits early phase of validation, creating bottlenecks in the product development cycle. An AIML based methodology is presented in this paper to predict the HSVD cycles for damper validation. The AIML algorithm was trained using the historical test data and
Kabbin, Chetan D., Suryawanshi, Vishal, Daphal, Pratap, Kulkarni, Prasad
Design & Optimization of CV shaft system to address powertrain induced NVH issues2026-26-0336To be published on 01/16/2026
The automotive industry is a crucial sector that plays a significant role globally. Government policies have a profound impact on this automotive industry in defining the regulatory standards and emission controls. Such regulations incentivized automakers to invest in research and development complying those standards towards reduction of vehicle emission which intern result in higher torsional vibrations and excitations amplitudes. To address the rising NVH related concerns in driveline system. Drive shafts (CV shafts) is an important component in power-train system in vehicle. Drive shaft’s main purpose to transfer torque from engines to wheels at multiple speeds with different articulation angles. The roughness generated by the engine follows a transfer path from engine to transaxle and transaxle to half shafts in monocoque vehicles which generates discomfort to the drivers whenever the vehicle is driven. The roughness can also be addressed by proper design of driveshaft stiffness
M A, Abdul Azarrudin, Jayachandran, Suresh kumar, KUMAR, SHIVANI, Bhardwaj, Kinshuk, M, DEVAMANALAN, Kanagaraj, Pothiraj
High-Frequency Dynamic Stiffness Measurements of Automotive Elastomers for Electric Vehicles2026-26-0312To be published on 01/16/2026
The increasing adoption of electric vehicles (EVs) has intensified the demand for advanced elastomeric materials capable of meeting stringent noise, vibration and harshness (NVH) requirements. Unlike internal combustion engine (ICE) vehicles, EVs lack traditional powertrain-induced masking noise. In the automotive industry the dynamic stiffness of elastomers for internal combustion engines are determined traditionally using hydraulic test rigs up to test frequencies of max. 1000 Hz. Measurements in excess of these frequencies were not possible and are only carried out using computerized FE or CAE calculation models. Electric drive systems generate distinct tonal noise components in the high-frequency range up to 10 kHz , which are well perceptible even at low sound pressure levels. Consequently, the dynamic stiffness characteristics of elastomers up to 3000 Hz are critical for optimizing NVH performance. This study focuses on the high-frequency dynamic stiffness testing of automotive
Bohne, Christian, Gröne, Michael
Assessing Millable Polyurethane in Powertrain Mounting Applications: A Comparative Study with Natural Rubber2026-26-0289To be published on 01/16/2026
In the automotive industry, the performance and longevity of elastomer components are critical to both vehicle durability and driver comfort. Powertrain mountings, play a crucial role in isolating vibrations and reducing noise. Traditionally, natural rubber (NR) has been the material of choice for these applications due to its excellent vibration isolation properties, flexibility, and cost-effectiveness. However, with evolving performance demands, there is growing interest in enhancing the durability and noise, vibration, and harshness (NVH) characteristics of powertrain mountings, along with improving their resistance to environmental stressors such as heat, oil, and wear. Unlike NR, which tends to degrade more quickly under such conditions, millable polyurethane (MPU) offers superior resistance, making it a promising candidate for extending the service life of these critical components. The objective of this study is to determine whether millable polyurethane (MPU) can serve as a
Murugesan, Annarajan, Pawar, Rohit
New generation Natural Rubber-Based Bump Stopper with Improved NVH Characteristics2026-26-0292To be published on 01/16/2026
In automotive suspension systems, components like bump stoppers and jounce bumpers play critical roles in controlling suspension travel and enhancing ride comfort. Material selection for these components is driven by functional demands and performance criteria. Traditionally, Natural rubber (NR) has traditionally been favoured for bump stopper applications due to its excellent vibration absorption, tear resistance, cost-effectiveness, and biodegradability. However, in more demanding environments, it has been largely replaced by microcellular polyurethane (PU) elastomers, which offer superior durability, environmental resistance, and enhanced noise, vibration, and harshness (NVH) performance. PU's high compressibility, low lateral expansion, and low compression set make it the material of choice across automotive, aerospace, and industrial sectors. Other materials like thermoplastic elastomers (TPE/TPU) and EPDM rubber are also used, offering advantages such as recyclability, ease of
Murugesan, Annarajan, Perumal, Mathavan
Refinement of Road Induced Steering Wheel Vibration in Electric Vehicle2026-26-0337To be published on 01/16/2026
Nowadays, customers expect excellent cabin insulation and superior ride comfort in electric vehicle. OEMs focuses on fine tuning the suspension system in electric vehicle to isolate the road shocks which finally offers superior ride quality. This paper focuses on the enhancing the ride comfort by reducing the steering wheel vibration which mainly originates due to road inputs. Higher steering wheel vibrations are perceived on the test vehicle when driven on rough road at the speed of 50 kmph. To determine the predominant force transfer path, Multi reference Transfer Path Analysis (MTPA) is performed on the front and rear suspension. Based on the finding from MTPA, various recommendations are explored and the effect of each modification is discussed. Apart from this, Operational Deflection Shape (ODS) analysis is carried out on the entire steering system to identify the deflection shape at the operating condition. Based on ODS findings, recommendations like dynamic stiffness
S, Nataraja Moorthy
Boosting the development of a BEV Rear Twist Beam suspension through a pioneering approach: ADAMS Real Time on Driving simulator2026-26-0397To be published on 01/16/2026
Twist beam suspensions are widely utilised in passenger vehicles because of their simplicity and cost-efficiency, yet they provide engineers with a complex challenge as their performance depends entirely upon the structural properties of the beam itself. Traditional methodologies rely on the generation of Modal Neutral Files (MNF) based upon vehicle dynamics requirements and packaging constraints, which is a highly time-consuming process that starts failing to fulfil the demands of a market where development times are being exponentially reduced. Besides this, part of flexible body’s real behaviour might be lost in the process of converting multibody models into parametric ones, which, in turn, presents difficulties in modifying compliant-related items. Thanks to a novel approach followed jointly by Mahindra and IDIADA, quick identification and optimisation of key tuneable items is achieved by employing a hybrid solution that combines full flexible and FE elements in ADAMS Car
Osorio, Alejandro García, Prabhakara Rao, Vageesh, Asthana, Shivam, Rasal, Shraddhesh
Development of a Lightweight Front-End Structure Using Injection Molding Technology2026-26-0304To be published on 01/16/2026
This paper presents the development of a lightweight, functionally integrated Front-End Module (FEM) utilizing plastic-metal hybrid injection molding technology. The objective is to achieve modularization, part consolidation, weight reduction, and cost efficiency. The proposed design integrates multiple components into a single module which makes assembly faster and easier. A mounting strategy with fixation features was integrated into the structure to effectively support various components.To ensure structural performance, component-level Finite Element Analysis (FEA) was performed, including static strength, bending and torsional stiffness, hood retention tests, and modal analysis. Ribbing patterns were optimized to meet design stiffness targets while minimizing weight. Moldflow analysis was carried out to evaluate manufacturability, focusing on gate design, weld lines , warpage, and flow balance. Necessary design corrections were implemented prior to tool development to ensure
Srivastava, Sanjay, Thakoor, Shruti Ghanashyam, Sonkusare, Shailesh
Smart Multilink Cabin Suspension with Detachable Stabilizer Mechanism for Improved Ride Comfort and Maintenance Efficiency in Vehicle Cabins.2026-26-0088To be published on 01/16/2026
This paper presents the design and development of a novel suspension system for vehicle cabins, specifically aimed at improving ride comfort and reducing maintenance time and costs. The system features a detachable stabilizer bar pivotally coupled to a pair of brackets connected to the vehicle chassis. The stabilizer bar is removably connected to a pair of connecting links, which in turn are oupled to a second pair of brackets attached to the cabin. This configuration allows for easy access to the engine bay during maintenance without disassembling the entire suspension system. Additionally, the system includes damper units and pivot arms that enhance ride comfort by isolating vibrations from the chassis. The proposed design is particularly beneficial for commercial vehicles with fixed cabins, as it reduces idle time during engine overhaul and improves overall ride quality for occupants.
K, Akilan, Pardeshi, Mahesh, Mistri, Pratikkumar, Navsariwala, Prashant
Experimental Evaluation of Tyre Vertical Dynamic Stiffness and Damping for Ride Model Applications Using Flat Trac2026-26-0607To be published on 01/16/2026
The damping and vertical dynamic stiffness of a tyre are critical to ride comfort and overall dynamics, particularly for low-frequency excitations in urban and highway driving. Accurate ride models depend on precise tyre parameterization, as tyres are the primary interface between the vehicle and the road, absorbing surface irregularities before the suspension engages. This study investigates an experimental methodology characterizing the vertical dynamic behaviour of pneumatic tyres using a Flat Trac test machine. Contrary to the conventional approaches that depend on intricate shaker rigs or frequency dependence function models, the proposed technique uses a realistic force displacement loop-based technology which is appropriate for ride model applications. Dynamic stiffness is calculated as the peak force divided by peak displacement during vertical sinusoidal excitation. Damping is derived from hysteresis energy loss per cycle. The tests were conducted under various conditions by
Duryodhana, Dasari, Sethumadhavan, Arjun, Tomer, Avinash, Ghosh, Prasenjit, Mukhopadhyay, Rabindra
Methodology for optimizing the bench testing of Steering I shaft using vehicle level data to reduce overall product development time and cost.2026-26-0560To be published on 01/16/2026
Steering I-shaft with rubber coupling (or hardy disc) is an important part of complete steering system mainly in body on frame vehicles. Hardy discs are used to dampen the vibrations that transmit to steering wheel through frame, steering gear and I-shaft. They also support to accommodate the variation between frame and BIW of body on frame vehicles. They are made up of rubber or other polymer composites, which have less torsional stiffness as compared to metals. The overall torsional stiffness of steering system reduces since the hardy disc is used in series in steering system, that impacts on the overall performance of steering system. So, during development I shafts with different design, stiffness of hardy discs are used to optimize the steering and NVH performance of vehicle. Considering the development time and cost, each design of I-shaft cannot be validated at vehicle level. The torsional and axial force or displacement of hardy disc is measured at vehicle level on different
Kabdal, Amit
Comprehensive Evaluation of Bolster Behavior: Field Data Insights for Design Modifications2026-26-0497To be published on 01/16/2026
Bogie suspension systems are increasingly being used in tipper vehicles to enhance their performance and durability, especially in demanding environments like construction and mining areas. Bolsters play a very crucial role in the bogie suspension systems of tipper vehicles, contributing significantly to their overall performance and durability. Bolsters help in evenly distributing the load across the suspension system, reducing stress on individual components and enhancing the vehicle’s stability. They act as shock absorbers, mitigating the impact of rough terrains and heavy loads, which is essential for maintaining the structural integrity of the vehicle. By dampening vibrations, bolsters improve ride comfort and reduce wear and tear on the vehicle’s components, leading to longer service life. Bolsters assist in maintaining proper alignment of the suspension system, ensuring optimal performance and safety. This study focuses on the comprehensive testing and evaluation of bolsters to
V Dhage, Yogesh, Kolage, Vikas
EVALUATION OF DRIVELINE NVH PERFORMANCE USING LINEAR DYNAMIC FINITE ELEMENT SIMULATION2026-26-0322To be published on 01/16/2026
Automotive driveline design plays an important role in the NVH characteristics of the overall vehicle. Driveline systems are an integral part of delivering torque from the engine/transmission to the tires which propel the vehicle and drivelines often experience a wide frequency of excitation which poses unique NVH challenges. With the increasing trend in the automotive industry to introduce turbocharged engines with fewer cylinders while delivering the same torque / power, the driveline systems are excited with increased lower frequency torsional vibration in addition to other vibrations transmitted from powertrain and road. In this paper, we address the key design consideration for developing an optimal driveline system with consideration to NVH while keeping durability and other functional requirements in perspective. We consider the example of a front wheel drive-based vehicle architecture with independent suspension. The effect of fundamental prop shaft frequency to determine
JOSHI, ATUL KAMALAKARRAO, Subramanian, MANOJ
Achieving ride comfort in bus suspension by varying air spring performance2026-26-0081To be published on 01/16/2026
Air springs are widely used in commercial buses to obtain better quality of ride and comfort. Selecting the right air spring is a critical aspect of suspension design. However, this selection process is often constrained by the limited availability of off-the-shelf components as the development of a custom air spring involves long lead time and high tooling cost. This can be justifiable only at high production volumes. Air springs are tunable as compared to conventional mechanical metal springs. Their performance can be adjusted by varying the internal air pressure and volume, enabling them to accommodate a wide range of vehicle load conditions. In actual design practice, component packaging constraints and fixed mounting dimensions often restrict the choice of air spring. Additionally, Front and rear suspension requires air springs with different characteristics. To overcome these limitations, an auxiliary air tank is also called a ping tank that can be used along with an existing
Patre, Kamlesh, Salunkhe, Swapnil, Paranjape, Shekhar
Novel Approach on Material characterization Testing of various Wiring Harness2026-26-0548To be published on 01/16/2026
The automotive wiring harness (length of 4-5 km) is a very important and complex system in the development of a modern car due to a lot of new electric & electronic components and sensors. It is a very sensitive material unlike metals and is considered as a composite which is highly anisotropic in nature, as it consists of several different layers of copper/aluminum strands and insulation. Because of insulation, wiring harness exhibits viscous plastic behavior which is crucial in determining the durability and long-term performance of the cables. Material properties play an important role in determining the behavior of wiring harness after assembly into the car. Wiring harness may undergo Bending, Torsion and Tension loads, causing the stress and strain in the individual electrical wires. The lack of CAE validation of the wiring harness routing may lead to extra costs for the automotive OEMs over a period. This paper describes the novel method of Testing the Cables and Bundles used in
Beesetti, Siva, Kalkala Balakrishna, Prasad, James Aricatt, John, SHAH, Dipam, Tas, Onur, Krogmann, Stephan
Simulation-Driven Load Spectrum Prediction_ Virtual RLDA for Chassis and Suspension System2026-26-0095To be published on 01/16/2026
In the rapidly evolving and highly competitive automotive industry, manufacturers are under immense pressure to bring products to market quickly while meeting customer expectations. As a result, optimizing the product development timeline has become essential. Structural integrity analysis for chassis and suspension systems lies in the accurate acquisition of operational load spectra, conventionally executed through Road Load Data Acquisition (RLDA) on instrumented vehicles subjected to proving ground excitation. At this point, RLDA is mainly used for final validation and fine-tuning. If any performance shortfalls, such as premature component failure or durability issues, are discovered, they often trigger design revisions, prototype rework, and additional testing This study proposes a Virtual Road Load Data Acquisition (vRLDA) methodology employing a high-fidelity full-vehicle multibody dynamic (MBD) representation developed in Adams Car. The system is parameterized and uses high
Goli, Naga Aswani Kumar, PRASAD, TEJ PRATAP
Balancing Ride Comfort: Optimizing Semi-Active Suspension Systems Through Multi-Objective Parameter Tuning2026-26-0594To be published on 01/16/2026
Optimizing semi-active suspension systems for ride comfort presents significant challenges due to the inherently conflicting requirements of different ride conditions. Enhancing primary ride associated with low-frequency body motions—may compromise the system’s ability to handle secondary ride, which involves mid-frequency road irregularities. Conversely, tuning for impact loadcases like potholes or road discontinuities often introduces trade-offs that can worsen comfort or suspension performance under regular driving conditions. These conflicts necessitate a systematic approach to identify balanced suspension behavior across diverse frequency bands. This study focuses on the parameter tuning of a smart damper within a semi-active suspension system to optimize overall ride performance. The investigation is carried out using a high-fidelity vehicle model in ADAMS Car, while mode-FRONTIER is employed to perform multi-objective optimization. This approach targets specific tunable blocks
Mishra, Satyakam, Verma, Rahul Ranjan, PRASAD, TEJ PRATAP
Nitrogen Absorption/Desorption (Gas Dissolution) in Aircraft Shock AbsorbersAIR6942 (Current)11/26/2025
This document outlines the current state of the art in the understanding of gas in solution in shock absorber oils in unseperated shock absorbers. A literature review, overview of Henry's law, Henry's law coefficients for known gas and oil couples, in-service operational problems, lessons learned, and potential future work will be discussed in the document.
A-5B Gears, Struts and Couplings CommitteeNEW
Necessity of Body Torsional Rigidity of Personal Mobility Vehicles (PMVs) with an Inward Tilting Mechanism2024-32-001304/18/2025
In traditional four-wheeled automobiles, the imbalance between the roll moment, which is the product of the centrifugal force during a turn acting on the center of gravity and the height of the center of gravity, and roll stiffness, which is the product of the left-right difference in tire vertical load and the tread width and commonly used among automotive suspension engineers, of the front and rear sections necessitates body torsional rigidity. However, there is a lack of specific cases and guidelines for constructing the body structure of three-wheeled PMVs (Personal Mobility Vehicles) with a tilting mechanism from the perspective of vehicle dynamics characteristics. In this paper, the basic considerations related to the dynamics of such three-wheeled PMVs are investigated. We use the term “torsional rigidity” to refer to the stiffness as the torsional deformation of the body itself, and the term “roll stiffness” to refer to the moment that counteracts the roll moment during a turn
Haraguchi, Tetsunori, Kaneko, Tetsuya
Fatigue Analysis of Motorcycle Rear Swing Arm on Different Road Surfaces2024-32-004604/18/2025
The rear swing arm, a crucial motorcycle component, connects the frame and wheel, absorbing the vehicle’s load and various road impacts. Over time, these forces can damage the swing arm, highlighting the need for robust design to ensure safety. Identifying potential vulnerabilities through simulation reduces the risk of failure during the design phase. This study performs a detailed fatigue analysis of the swing arm across different road conditions. Data for this research were collected from real-vehicle experiments and simulation analyses, ensuring accuracy by comparing against actual performance. Following CNS 15819-5 standards, road surfaces such as poorly maintained, bumpy, and uneven roads were tested. Using Motion View, a comprehensive multi-body dynamic model was created for thorough fatigue analysis. The results identified the most stress-prone areas on the swing arm, with maximum stress recorded at 109.6N on poorly maintained roads, 218.3N on bumpy surfaces, and 104.8N on
Chiou, Yi-Hau, Hwang, Hsiu-Ying, Huang, Liang-Yu
Test Methodology Development For Rig Level Validation Of Light Weight Stabilizer Link Of EV Bus Suspension2024-26-035701/16/2024
In the modern and fast growing automotive sector, reliability & durability are two terms of utmost importance along with weight ad cost optimization. Therefore it is important to explore new technology which has less weight, low manufacturing cost and better strength. The new technology developed always seek for a quick, cost effective and reliable methodology for its design validation so that any modification can be made by identifying the failures. This paper presents the rig level test methodology to validate and to correlate the CAE derived strain levels, life cycle & failure mode of newly developed light weight stabilizer link for EV Bus suspension. Stabilizer link replaces the existing separate arrangement of anti-roll bar and parallel rods and light in weight by 30kg.This stabilizer link arrangement is having the short lever arms which are connected through torsion bar which goes under twisting moment and the short lever arms are intended to control wheel motion in longitudinal
Tangade, Atul Bandu, Babar, Sunil, Bankar, Milind Achyutrao, Mehendale, Ravindra, Dhumal, Kailas, Bhusari, Deepak
Exploring capabilities of hydraulic actuators to achieve vehicle ride targets in frequency range beyond their operational bandwidth2024-26-006001/16/2024
Active suspension systems employ sophisticated control algorithms to deliver superior comfort in vehicles. However, the capabilities of these algorithms are limited by the physical constraints of actuators. Many vehicles use hydraulic actuators in their active suspension system, which use fluid movement to control suspension motion. These systems inherently have slower response times due to the nature of fluid flow and the time required to build up or release pressure within the hydraulic system. Typically, hydraulic systems operate in a low bandwidth of 0-5 Hz. This limits their capability to only meeting vehicle’s primary ride targets which typically lie below 5 Hz. Although, they can be tuned to operate at slightly higher frequency range (up to 10 Hz), they perform poorly in attenuating the secondary ride vibration, i.e., 5 – 25 Hz. This paper focuses on identifying and developing control strategies that can allow us to affect the vehicle ride well beyond the actuator bandwidth. The
Agrawal, Ayush, Negi, Ayush, Joshi, Divyanshu
A comparative study of vehicle handling characteristics of commercial vehicle with innovative nonlinear stiffness mono-leaf suspension with parabolic spring suspension through simulation2024-26-005701/16/2024
In recent years due to significant increased cost of raw material, fuel and energy, vehicle cost is increased. As vehicle cost is one of the major factors that attracts prospective buyers, it has created specific demand for low weight and low-cost components than traditional components with better performance to meet customer expectations. Suspension is one of the critical aggregates where lot of material is used and reduction in weight tends to give lot of cost benefit. As suspension system derives vehicle's handling performance, it has to be ensured that handling performance of vehicle is maintained the same or made better while reducing weight of the suspension. Advancements in simulation capabilities coupled with manufacturing technology has enabled development non-traditional leaf springs. One of such springs is mono-leaf spring without. This type of leaf spring provides advantages such as low weight and nonlinear stiffness. Hence, this type of spring can cater the need of soft
Pandhare, Vinay Ramakant, Tiwari, Chaitanya, Deore, Yogesh, Khandekar, Dhiraj
HVAC NVH Refinement in Electric Vehicle2024-26-020601/16/2024
Customers expect much more advanced features and comfort in electric vehicles. It is challenging for NVH engineers to reduce the vibration levels to a great extent in the vehicle without adding cost and mass. This paper focuses on reducing the tactile vibration in electric vehicle when AC is switched on. Vibration levels were high and modulating in nature in test vehicle. Electric compressor is used for cabin cooling and battery cooling in the vehicle. Compressor is connected to body with the help of isolators. Depending upon cooling load, the compressor operates between 1000 rpm and 8000 rpm. The 1st order vibration of compressor was dominant on tactile locations at all the compressor speeds. Vibration levels were improved by reducing the dynamic stiffness of isolators . To reduce the transfer of compressor vibration further, isolators are provided on HVAC line connection on body and mufflers are provided in suction and discharge line to reduce the effect of pulsation. With the above
S, Nataraja moorthy, Rao, Manchi, Raghavendran, Prasath, Manivannan, Giridharan
Tire-Rim Impact failure prediction using mathematical model2024-26-031401/16/2024
Early design or concept phase involve decision of key Chassis & Suspension parameters finalization, in which tire size selection is one of the most important aspect. Tire size affects overall vehicle ride & handling, steering performance and styling. In addition, it will dictate the majority of suspension packaging in subsequent design phase. An improper tire size selection can lead to major design changes in later stages and cause delay in the project deliverables. Conventional method of tire size selection mainly based on load rating using Tire standards like ETRTO, JATMA etc. is sufficient for vehicle application & basic durability point of view but lacks the insight for typical tire-rim impact failure mode. Aim of the study is to develop the methodology of predicting durability failure especially kerb strike event using simplified suspension-tire mathematical model, which will help in selection of optimal tire size or its specifications in early design phase to mitigate the impact
Atal, Abhishek, Lakhera, Vivek
Investigating The Factors Affecting Cabin Comfort for Agricultural Machinery2024-26-006701/16/2024
Customer expectations for cabin tractors from comfort perspective has grown multifold in the recent years. Cabin noise and vibration is one of the crucial parameter which drives comfort feel for the customer. This would enable customer to remain comfortable during long working hours. Moreover, Cabin Tractors with lesser noise levels found to have better acceptance by Customers all over the world. The Nebraska reports studied for US based tractor shows evolution of trend of cabin noise in 100-150hp tractors in last couple of decades. Undoubtedly, tractor manufacturers have put lot of efforts towards meeting legislation demand & stringent customer requirements for European and US market. This paper presents the work carried out for investigating major contributing factors affecting tractor cabin Noise & Vibration for an existing 75HP tractor. Virtual and experimental studies have been carried out to identify the principal source of noise and the transfer paths for cabin noise
Chavan, Amit, K, Somasundaram, gunasekaran, Pandiyanayagam, Chaudhari, Vishal V, Sati, Navin
Countermeasures for Low Frequency Boom noise Reduction in Electric Vehicle2024-26-021401/16/2024
Electric vehicles are much quieter than IC engine powered vehicles due to less mechanical components and absence of combustion. The lower cabin noise in electric vehicles make customers sensitive to even small disturbance in vehicle. Road boom noise is one of the major concerns to which the customers are sensitive in electric vehicles. The test vehicle is a front wheel driven compact SUV powered by electric motor. In normal plain road, noise levels are acceptable but when the vehicle has been driven on coarse road, the boom noise is perceived, and the levels are objectionable. Multi reference Transfer path Analysis (MTPA) is conducted to identify the path through which maximum forces are entering the body. Based on MTPA, modifications are proposed on the suspension bushes and the noise levels were assessed. Operational deflection shape (ODS) analysis is conducted on entire vehicle components like suspension links, sub frame, floor, roof, and doors to identify the deflection pattern of
S, Nataraja moorthy, Rao, Manchi, Raghavendran, Prasath, Selvam, Ebinezer
Development of India specific biaxial test cycle for fatigue testing of wheel rims and wheel hub bearings for Heavy Commercial Vehicles2024-26-032201/16/2024
Wheel rims and wheel hub bearings are critical components of Heavy Commercial Vehicle (HCV) suspension systems and are subjected to extensive fatigue loading throughout their operational life. Actual loading conditions on wheels are a combination of radial loads (vertical loads) and cornering loads (lateral loads) acting simultaneously and are directly influenced by payload and road conditions. Currently for Indian usage, there are test guidelines only for separate uniaxial Radial Fatigue Test (RFT) and Cornering Fatigue Test (CFT) for wheel rims which might not represent realistic combined loading conditions, and no generic guidelines are available for testing of wheel hub bearings. There is a biaxial test guideline defined for European usage scenario, but no guidelines defined for Indian usage scenario. Thus, there was a need to define test guidelines for biaxial fatigue testing of wheel rims and wheel hub bearings, based on data acquired for Indian roads and usage conditions, which
Thorat, Omkar A., Bakal, Nikhil R., Kuwar, Virendra S., Pawar, Prashant R., Shinde, Vikram V.
Effect of Lift Axle suspension design on Heavy Commercial Vehicle Handling performance2024-26-004901/16/2024
The cost of fuels used for automobile are rising in India on account of high global crude oil prices. The fuel cost constitutes major portion of total cost of operation for Heavy commercial vehicles. Hence, the trend is to carry the goods transport through higher payload capacity rigid trucks that offer lower transportation cost per unit of goods transported. This is driving the design of multi-axle heavy trucks that have lift axles. In addition, improved network of highways and road infrastructure is leading to increase in average operating speed of heavy commercial vehicles. It has made increased focus on occupant as well as road safety while designing the heavy trucks. The load carried by lift axles is equivalent to the steered axle or drive axle. Hence, the analysis of lift axle suspension from the point of view of vehicle handling and stability is essential. There are two basic kinds of lift axle designs used in heavy commercial vehicles: caster steered lift axle having single
Vichare, Chaitanya Ashok, Raval, Chetan, Patil, Sudhir
SUV Multi-Link Rigid Axle Control Links Optimization for Ride and Handling Improvement2024-26-004801/16/2024
In automotive world, role of suspension system is to absorb vibrations from the road, and to provide stability while vehicle is going over bumps or uneven roads, cornering, acceleration and braking etc. For body on frame SUVs which are typically characterized by high center of gravity, it is quite critical to find best balance in ensuring stability of the vehicle and having comfortable ride performance. Rigid axle rear suspension is quite typical choice in such vehicles, wherein lower and upper control links are two important components subjected to lateral, longitudinal, and vertical loads. These links allow the vehicle to move smoothly throughout the entire range of suspension travel. Kinematics and compliance optimization of these links is major factor in definition of ride-handling performance of the vehicle. The present study describes key challenges and methodology to define position as well as orientation of control links, where-in multiple inter-related handling and comfort
Hussain, Inzamam, Jani, Harshil, Rasal, Shraddhesh, Asthana, Shivam, ahire, Manoj, Jadhav, Prashant, Lenka, Visweswara, Vellandi, Vikraman
The science of Engine Mounts and its multidimensional impact on Noise and Vibrations in passenger car2024-26-020301/16/2024
A robust process of specifying engine mounting systems for internal combustion engine (ICE) powertrains have been established through decades of work and countless applications. Vehicle vibration is a critical consideration in the early stage of vehicle development. Apart from comfort, it also affects the overall vehicle's performance, reliability, Buzz-squeak & rattle (BSR), parts durability and robustness. The most dynamic system in a vehicle is the powertrain, a source of vibration inputs to the vehicle over the frequency range. The mounting system supports a powertrain in a vehicle and isolates the vibration generated from the powertrain to the vehicle. In addition, it also controls the overall dynamic movement of the powertrain system when the vehicle is subjected to road load excitations and avoids contact between the powertrain and other adjacent components of the vehicle. This paper investigates the effect of the mounting position, stiffness, and progressivity on overall
Hazra, Sandip, Mohare, Gourishkumar
Comparative study of bending loads on rear axles of heavy commercial vehicles for two different real leaf spring configurations2024-26-037401/16/2024
In commercial vehicles, leaf springs play a major role in designing the suspension system. Leaf springs are the mostpopular designs having multiple leaves in contact with each other and show hysteresis behavior when loaded and unloaded. The leaf spring acts as a linkage for holding the axle in position and thus separate linkages are not necessary. It makes the construction of the suspension simple and strong. Because the positioning of the axle is carried out by the leaf springs, it is disadvantageous to use soft springs i.e. springs with low spring constant. Leaf springs are excellent in suspending large loads, since they are designed using 'bending beam' equations. The stiffness of the leaf spring assembly can be altered as desired, by changing the number of leaves. The objective of this paper is to compare the bending loads coming at the rear wheel centers of the vehicle when it runs in torture track and over a single bump. Bending loads were compared for the same rear suspension
Korrayi, Rajesh, Dixit, Vishnu
Driveline Vibration Reduction in Light Weight All Wheel Drive Vehicle2024-26-022901/16/2024
The test vehicle is All Wheel Drive (AWD) vehicle which is powered by four-cylinder engine. The power is transferred from the powertrain to the wheel through power transfer unit (PTU), propeller shaft, flexible rubber coupling and Integrated Rear Differential Assembly (IRDA) . Higher Boom noise and vibration levels are observed when driving the vehicle at 5th gear WOT conditions. 2nd order NVH levels are dominant from 1200 rpm to 2000 rpm and 4th order NVH levels are dominant at 2300 rpm. Operational deflection shape (ODS) analysis is carried out on entire vehicle to identify the location where maximum deflection is observed at the problematic frequency. It is identified that higher torsional excitation from the powertrain is exciting the IRDA pitching mode and the propeller shaft bending mode which is the reason for higher 2nd order and 4th order NVH levels. The driveline forces are entering the body through the IRDA and rear cradle bushes. The dynamic stiffness of IRDA bushes is
S, Nataraja moorthy, Rao, Manchi, Raghavendran, Prasath
Accelerated Lab Test facility for NRS Leaf Spring bracket for HCV Application2024-26-034401/16/2024
In the modern automotive sector, durability and reliability are the most common terms. Customers are expecting a highly reliable product but at low cost. Any product that fails within its useful life leads to customer dissatisfaction and affects the reputation of the OEM. To eradicate this, all automotive components undergo stringent validation protocol, either in proving ground or in lab. This paper tails on developing an accelerated lab test methodology for NRS leaf spring bracket by simulating field failure. Initially, potential failure causes for spring bracket were analyzed. Road load data was then acquired at proving ground and customer site to evaluate the damage on the spring bracket. To simulate the field failure, lab test facility was developed, reproducing similar boundary conditions as in vehicle. Field failure was simulated with the existing design samples and Improved design of spring bracket was validated in the same test conditions and compared with the life of existing
G, Manthiramoorthy
NVH Refinement of Structure borne tonal noise in electric vehicle2024-26-019801/16/2024
Globally all OEMs are moving towards electric vehicle to reduce emission and manage fuel cost. Customers expect highest level of refinement and sophistication in electric vehicle. At present, the customers are sensitive to high pitched tonal noise produced by electric powertrain which gives a lot of challenges to NVH engineers to arrive at a cost-effective solution in less span of time Higher structure borne tonal noise is perceived in electric vehicle at the vehicle speeds of 15 kmph and 60 kmph. The test vehicle is front wheel drive compact SUV powered by motor in the front. The electric powertrain is connected to subframe with help of three mounts. Transfer path analysis (TPA) using blocked forces method is carried out to identify the exact forces of the powertrain. Powertrain mount is characterized by applying the predicted forces and dynamic stiffness at problematic frequency is measured. By reducing the dynamic stiffness of powertrain mounts, the noise levels are reduced by ~ 5
S, Nataraja moorthy, Rao, Manchi, Raghavendran, Prasath, Selvam, Ebinezer
Analysis and Annihilation of Grunt Noise in Hydraulic Power Assisted Steering Systems2024-26-021801/16/2024
Hydraulic steering systems employ pressurized fluid to alleviate the effort needed to steer the wheels of an automobile. Hydraulic Power Assisted Systems (HPAS) are cost-efficient, yet intricate. As customer trends lean towards reduced effort and improved handling, HPAS must intervene more in steering, leading to increased pressure requirements from the HPAS pump. Consequently, HPAS components must withstand higher pressure liquid and operate with closer tolerances, occasionally resulting in anomalous functioning. This paper delves into one anomaly with HPAS systems "Grunt Noise", a phenomenon caused by the resonance of the Torsion bar (T-bar) with fluid pressure pulsations. An extensive study was conducted to identify load conditions for grunt noise generation, examine transfer paths and analyze its frequency band. The study also explored the cascading process, reproducing the vehicle-level phenomenon at the rig-level for the Rack and Pinion and later at Pinion Valve assembly level
SETHI, AJITESH, Titave, Uttam, Vardhanan K, Aravindha Vishnu, Zalaki, Nitin, Naidu, Sudhakara
Analysis and Reduction of Abnormal Suspension Noise in Sports Utility Vehicle2024-26-021701/16/2024
This paper focuses on reducing abnormal noise originating from suspension when driving on rough road at the speed of 20 kmph. The test vehicle is a front wheel driven monocoque SUV powered by four cylinder engine. Cabin noise levels are higher between 100 to 800 Hz. Vibration levels are measured on front and rear suspension components, front and rear subframe, subframe connections on body to identify the noise source locations. Since the noise levels are dominant only in certain rough patches at very narrow band of time, wavelet analysis is used for problematic frequency identification. Based on wavelet analysis, it is identified that the vibration levels are dominant on front lower control arm (LCA) due to inferior isolation performance. The dynamic stiffness of LCA bushes is reduced by ~ 30% to improve the isolator performance which reduced the noise levels by ~ 2 dB (A). Modal analysis is conducted on suspension components like LCA, stabiliser bar, shock absorber, tires and front
S, Nataraja Moorthy, Rao, Manchi Venkateswara, Raghavendran, Prasath, Manivannan, Giridharan
Influence of Rear Suspension Local Stiffness on Full vehicle Ride & handling Performance2024-26-006101/16/2024
One of the biggest challenges for automotive industry is with respect to material saving and to have control on cost of development and still meeting performance in each aspect. Stringent weight targets help industries to have good margin on component costs. In recent times we have seen vehicle underbody contribution to total vehicle is significant in range of 12% to 18%. Total weight directly impacts the range of electric vehicle which is a key metric for success from real-world usage point of view and customer appeal. Hence control on suspension and frame design for light weighting is prominent trend in industry, this leads to deterioration of suspension compliance as well as vehicle ride and handling performance. Sub-frame and knuckle play crucial role in definition of overall suspension stiffness. Present Study focusses on electric vehicle rear cradle design for weight saving with minimum reduction of stiffness. Understanding compliance which obtained from frame\cradle in vehicle
Asthana, Shivam, Rasal, Shraddhesh, Ganesh, Lingadalu, V, Jesse Daniel, Nidasosi, Basavraj, Ramkumar, J, NAYAK, Bhargav, M, Sudhan, Vellandi, Vikraman
Experimental Analysis of Multi-Link Rigid Axle Suspension Camber Variation with Vehicle Load2024-26-005401/16/2024
Increased popularity on SUV category in the market has led to high focus on performance attributes of SUVs. Considering higher weight & CoG for achieving handling performance target is always a challenge. Static Wheel Alignment parameters, especially Camber have shown significant contribution in Handling attributes of vehicle. This paper presents an experimental study on change in wheel camber under the influence of different vehicle loading conditions. In SUVs, generally wheel is subjected to large deflection from its high static loads which makes it quite difficult to maintain an ideal camber angle. Hence, it is important to analyze the camber angle variations under actual loading conditions. An in-house fixture is developed to emulate the actual vehicle loading conditions at rear wheel end. The multi-link rigid axle suspension with watt's link assembly is mounted on the chassis-frame which is rigidly fixed to ground and loads are achieved through hydraulic actuators at Wheels. Axle
Jani, Harshil, Rasal, Shraddhesh, Hussain, Inzamam, Asthana, Shivam, ahire, Manoj, Vellandi, Vikraman, Senniappan, Moorthy
Vehicle Dynamics Simulation Correlation : Impact of Flexible Tyre and Flexible Frame in Comfort Prediction of Two Wheelers Motorcycles and Scooters2024-26-005301/16/2024
For any two wheeler vehicle development, rider and pillion comfort while driving the vehicles over different kinds of road perturbations holds high importance. Designing a vehicle for comfort starts at the very beginning of its layout definition through vehicle geometric parameters, key hardpoints, mass-inertia distribution of subsystems and suspension characteristics. There is a need for highly reliable simulation models for comfort predictions as any change in layout during subsequent design stages is a very costly affair. Accurately predicting comfort using a full vehicle model is a challenging task though as it depends on how realistic the Simulation Model is to that of actual vehicle. While suspension stiffness and damping characteristics remain critical parameters for the comfort, selection of tyres are known to hold equal importance in vehicle comfort. The details to which the tyres are captured in the simulation model and the formulation of tyre interaction with roads in a
Govindula, Srikanth, Pandey, Pradyumn, Saraswat, Udit, Mishra, Ashish
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