This SAE Recommended Practice establishes uniform test procedures for friction based parking brake components used in conjunction with hydraulic service braked vehicles with a gross vehicle weight rating greater than 4500 kg (10 000 lb). The components covered in this document are the primary actuation and the foundation park brake. Various peripheral devices such as application dashboard switches or indicators are not included. These test procedures include the following: a Brake Related Tests 1 Brake Functional Performance 2 Brake Dynamic Torque Performance 3 Brake Corrosion Resistance 4 Brake Endurance with Torque 5 Brake Endurance without Torque 6 Vibration Resistance 7 Brake Ultimate Static Load 8 Brake Lining Wear Adjuster Function b Actuation Related Tests 1 Mechanical Actuator Functional Performance 2 Mechanical Actuator Endurance 3 Mechanical Actuator Quick Release 4 Mechanical Actuator Ultimate Load 5 Spring Apply Actuator Functional Performance 6 Spring Apply Actuator

Truck and Bus Hydraulic Brake Committee

SCV Chassis Performance Optimization through Parametric Beam Modelling & Simulation

2021-28-018310/01/2021

In automotive product development, design and development of the chassis plays an important role since all the internal and external loads pass through the vehicle chassis. Durability, NVH, Dynamics as well as overall vehicle performance is dependent on the chassis structure. Even though passenger vehicle chassis has a ladder frame or a monocoque construction, small commercial vehicle chassis is a hybrid chassis with the cabin welded to the ladder frame. As mileage is critical for sale of SCVs, making a light-weight chassis is also important. This creates a trade-off between the performance and weight which needs to be optimized. In this study, a parametric beam model of the ladder frame & the cabin of the vehicle is created in COMSOL Multiphysics. The structure has been parameterized into the long member & crossmember geometry and sections. The model calculates the first 12 natural frequencies, global stiffness, and weight. It has been validated and further used for optimization study

THANAPATI, ALOK Ranjan, Bhalerao, Mihir, Deshmukh, Chandrakant, Krishnan, Hareesh

Brake Groan Noise Investigation and Optimization Strategy for Passenger Vehicles

2021-26-030109/22/2021

Groan is a low frequency noise generated when moderate brake pressure is applied between the surfaces of the brake disc and the brake pad at a low-speed condition. Brake groan is often very intense and can cause large numbers of customer complaints. During a groan noise event, vehicle structure and suspension components are excited by the brake system and result in a violent event that can be heard and felt during brake application. The cause of noise is friction variation of stick-slip phenomenon between friction material and disc. This paper discusses the approach for prediction and mitigation of brake groan noise for passenger vehicles having disc brakes. To identify the brake groan noise frequency, vehicle testing with operating condition for reproducing the groan noise is carried out and also impact frequency response analysis is performed to identify natural frequency of each chassis component like brake, suspension stud, lower control arm, knuckle etc. The finite element corner

Doundkar, Vikas, Iqbal, Shoaib

Felling Head Terminology and Nomenclature

J1272_202103 (Current)

03/01/2021

This SAE Standard is intended to describe the basic types of felling heads, including those with bunching capabilities, that are attachments to a self-propelled machine. Only the major components that are necessary to describe the functions of the felling head, and to apply the principles of the standard are included. Illustrations used are not intended to include all existing felling heads or to describe any particular manufacturer’s variation.

MTC4, Forestry and Logging Equipment

Nissan's 2021 Rogue is a COVID beater

21AUTP02_1402/01/2021

Nissan staff truly pulled out the stops to get the all-new 2021 Rogue into the market during the global pandemic. Rogue is the company's best-selling product in North America, by far - a testament to a well-considered overall package that designers, engineers and product planners have steadily evolved and improved since the model's launch in 2007. Now in its third generation (coded T33), the latest Rogue is underpinned by Nissan's C/D-segment architecture that shares more geometries with Sentra, itself a vastly upgraded and improved vehicle for 2021. “Last March, I was reviewing our program schedules and it looked like everything was going to get delayed due to Covid,” said Chris Reed, executive VP of R&D at Nissan Technical Center in Farmington, Mich. “At this time, we had delays in other programs due to a ‘development overload’ situation between suppliers and prototypes. The hatches were being battened down.

Brooke, Lindsay

Chassis Lightweighting Hole Placement with Weldline Evaluation

2020-01-049304/14/2020

Vehicle weight driven design comes amid rising higher fuel efficiency standard, and must meet the criteria - pass Proving ground test events that is equivalent customer usage. CAE Fatigue analysis for proving ground (CFP) is behind a success push to digitally simulate vehicle durability performance in high fidelity. The need for vehicle weight reduction often arises late in vehicle development phases when CAE Methods, time, and tangible cost effective opportunities are limited or non-existent. It is necessary to deploy a new CAE Method to identify opportunities for light-weighting hole placement in Chassis structures to deliver a cost effective light-weighting opportunity with no impact on fatigue life. The successful application of this methodology is on truck frame, which is key structural parts for vehicle chassis to support body and suspension and powertrain. By means of artificially adjusting the magnitude of load time history and material fatigue properties S-N curve, fatigue

Song, Gavin

Study on the Quantitative Relationship between Static Stiffness and Modal Parameters of an Aluminum Space Frame

10-04-02-000701/27/2020

In this article, the quantitative relationship between the static stiffness, lightweight factor, and modal parameters of an aluminum space frame was investigated. Modal theory calculation and finite element method were employed in the analysis. Fifty modal parameters were extracted from the finite element model of the frame to calculate the bending stiffness, torsional stiffness, and lightweight factor of the frame. The deviations of the bending stiffness, torsional stiffness, and lightweight factor obtained from the modal theory and the finite element theory were found to be 0.91%, 1.72%, and 1.71%, respectively. It indicates that these two methods have similar accuracy. It was confirmed that the sum of each order modal compliance could be used to calculate the static compliance of the aluminum space frame. The first-order bending mode was found to be the corresponding mode order, which made the largest contribution to the bending stiffness. This method is also applicable for

Wang, Zhenhu, Xia, Erli, Chen, Ziming, Xue, Zhigang, Li, Luoxing

Jeep revives its pickup mojo with 2020 Gladiator

19AUTP05_1505/01/2019

Get ready for the fractionalization of the U.S.'s raucous pickup-truck market. Launching what's surely one of the year's most-anticipated and potentially significant new models, Jeep engineers and planners insist they went out of their way to ensure the 2020 Gladiator was developed as a genuine pickup and not “a Wrangler with a bed.” But everyone knows Jeep would've been crazy to stray too far from the radiant demand for the new JL-generation Wrangler, so excuse us if the Gladiator does, well, at least look like just that: a 4-door Wrangler Unlimited-with a bed.

Visnic, Bill

FCA debuts new Ram Heavy Duty pickups

19AUTP03_1603/01/2019

FCA's Ram truck division unveiled its new 2019 Heavy Duty (HD) pickup truck lineup at the 2019 North American International Auto Show (NAIAS). The new HD pickups feature the slick interiors and tech from Ram's new 1500 line, significant powertrain and chassis upgrades and all-new front and rear sheetmetal. The Ram HD lineup will face off against Chevy's new HD pickup offerings and Ford's established F-Series and includes 2500/3500 capacities in regular, crew and mega-cab configurations. Since it's a heavy-duty truck launch, Ram is of course touting new capability figures for its HD lineup, which retains its basic cab architecture, but sees nearly every other part of its chassis upgraded. A new 6.7-liter turbo-diesel producing 1,000 lb·ft of torque-the first HD pickup to break the fourfigure torque-output barrier-combines with a redone frame that's now 98.5% high-strength steel to provide what Ram claims are class-leading figures of 35,100-lb (15,921-kg) towing and 7,680-lb (3,565-kg

Seredynski, Paul

Investigation of Cabin Noise while Accelerating on Low Mu Track through Simulation Approach Using Full Vehicle ADAMS/Car Model

2019-26-017901/09/2019

Cabin noise is a significant product quality criteria which enables the customers for product differentiation. There are various sources of cabin noise such as wind, structures(panels), engine, suspension, tire and roads. During product development phase, extensive tests has been conducted to improve vehicle dynamics behavior on various climatic conditions. One such test is accelerating vehicle on low mu or icy surface. While performing acceleration manoeuvre (tractions) on a low mu tracks, Cabin noise with source identified from front underbody & low tractive torque build up is reported. This undesirable behavior may occur due to following reason (1) Excitation of coupled modes between suspension and powertrain which induces torque fluctuation. (2) Transmissibility of various subsystem can be the reason for above problem statement. (3) Poorly chosen tire compounds and design leads to fluctuation in torque. A detailed simulation based study using ADAMS/CAR has been performed to assess

Singh, Vivek, Prasad, Tej, Srivastava, Harshit

A Mitigation Strategy for Steering Wobble Phenomenon in Passenger Vehicle

2019-26-018301/09/2019

Vehicles have a wide range of resonance band due to design nature & characteristics of its aggregates. First order, vehicle speed dependent, wheel disturbance due to wheel imbalances can result in excitation of different vehicle aggregates. Steering wobble refers specifically to first order road wheel excitation effects, in frequency range of 10-16 Hz, that manifest themselves as significant steering wheel torsional vibrations at highway speeds i.e. at the range of 80 km/h to 120 km/h on smooth roads. The tire, being an elastic body analogous to an array of radial springs, may exhibit variations in stiffness about its circumference; hence, it may vibrate at different frequencies due to wheel imbalance. This paper introduces dynamic steering wobble analysis methodology either using vehicle speed at Discrete (individual speeds) or by Sweep (low to high speed) method to investigate steering wobble in the virtual environment using the full vehicle MBD model. It is also suggested prior to

Pattathil, Arunmohan, Soherwardi, Omer, Iqbal, Shoaib

Visionary's Take: How a Vision Becomes a Company (Part 1 of 2)

1239310/17/2018

Can you become a visionary or are you born one? How does a visionary capture an opportunity and makes it a successful business? Are engineers more qualified to solve technical problems or run companies? SAE's "The Visionary's Take" addresses these and many other questions, by talking directly with those who have dared to tackle difficult engineering problems and create real-life products out of their experience. In these short episodes, Daniel Hutchinson, Founder and CTO of PostProcess Technologies talks about his experience in creating a brand-new company in the already competitive world of additive manufacturing, and specifically focusing on post-printing. Founded in 2014, PostProcess Technologies developed a unique triad of software, hardware and chemistry that works together to make the process of removing supports and surface finishing easier to deal with. This is the phase where mistakes can ruin a great manufacturing run: parts can break when their support is removed, for

Visionary's Take: How a Vision Becomes a Company (Part 2 of 2)

1239210/17/2018

Device for Measuring Efforts Generated by Tire in Steering Conditions

2018-36-011109/03/2018

Currently, large companies as well as universities have increased the studies into vehicular dynamic behavior, mainly in order to improve driver and passenger safety. Simulations with complete model vehicle have been used for these studies. The tire is one of the most important vehicular component as the only connection with the ground and responsible for transmitting all vertical, longitudinal and lateral forces, consequenetly it is the main component on the model vehicle, being crucial for the correlation between computer simulations results and field tests, This paper presents a methodology, development and construction of a device to obtain lateral forces in any combination of toe and camber angles for different conditions of normal load, the tests can be performed on any type of ground, whether dry or wet. The tire datas used as reference were obtained through an experimental test using “Flat Trac” equipment. Based on these data, the components used to measuare the tire force

Chicuta, Walace, Afonso, Bruno, Bortolussi, Roberto, Delijaicov, Sergio

A Material Efficiency Ratio to Evaluate the Methods for Improving the Torsional Rigidity of a Pickup Chassis Frame

2018-01-102404/03/2018

While offering improved crash worthiness and significant lightweighting opportunities, the increased use of advanced high strength steels (AHSS) may compromise the stiffness and NVH performance of vehicles due to reduced part thickness. Different methods to improve the torsional rigidity were studied on a pickup chassis frame. These methods include adding bulkhead pairs as reinforcement, increasing the thicknes of frame parts, and enlarging the closed sections on the rails. Structural optimization was conducted for each stiffness improvement method and the minimal mass increase required to reach the improvement targets was obtained. A material efficiency ratio μ is proposed in this research and used as a criterion to evaluate the efficiency of a mass increase to improve the structural stiffness and NVH characteristics of vehicles. Based on this parameter, the methods to improve the torsional rigidity of the pickup frame in all design spaces were evaluated. The adding bulkhead pair

Liang, Jianyong, Powers, Jonathan, Stevens, Scott

Pre-Shaping Bursty Transmissions under IEEE802.1Q as a Simple and Efficient QoS Mechanism

2018-01-075604/03/2018

The automotive industry is swiftly moving toward Ethernet as the high-speed communication network for in-vehicle communication. There is nonetheless a need for protocols that go beyond what standard Ethernet has to offer in order to provide additional quality of service (QoS) to demanding applications such as advanced driver-assistance systems (ADAS) or audio/video streaming. The main protocols currently considered for that purpose are IEEE802.1Q, audio video bridging (AVB) with the credit-based shaper (CBS) mechanism (IEEE802.1Qav), and time-sensitive networking (TSN) with its time-aware shaper (TAS) (IEEE802.1Qbv). AVB/CBS and TSN/TAS both provide efficient QoS mechanisms, and they can be used in a combined manner, which offers many possibilities to the designer. Their use however requires dedicated hardware and software components and clock synchronization in the case of TAS. Previous studies have also shown that the efficiency of these protocols depends much on the application at

Villanueva, Josetxo, Migge, Jorn, Boyer, Marc, Navet, Nicolas

A Tailor Welded Blanks Design of Automotive Front Rails by ESL Optimization for Crash Safety and Lightweighting

2018-01-012004/03/2018

Utilizing the tailor welded blanks (TWBs) design along with the latest AHSS grades for the front rails on a sedan was studied to reduce the weight of the vehicle and improve the crash safety performance. To find the most efficient material usage, the front rail parts were tailored into multiple blanks with varying thickness. A structural thickness optimization study of the tailored front rails was conducted for IIHS moderate overlap frontal crash, and the tailored blank thickness was set as design variable. The equivalent static loads (ESL) method was adopted for the thickness optimization, which allows many design variables to be optimized simultaneously. The torsion and bending stiffness of the sedan body in prime were set as design constraints, and would not be compromised. The optimal thickness configurations of the TWB designs by ESL optimization suggest that the weight of the frontal rails can be reduced by more than 30% while still maintaining the crash safety performance. These

Liang, Jianyong, Powers, Jonathan, Stevens, Scott

Scene Structure Classification as Preprocessing for Feature-Based Visual Odometry

2018-01-061004/03/2018

Cameras and image processing hardware are rapidly evolving technologies, which enable real-time applications for passenger cars, ground robots, and aerial vehicles. Visual odometry (VO) algorithms estimate vehicle position and orientation changes from the moving camera images. For ground vehicles, such as cars, indoor robots, and planetary rovers, VO can augment movement estimation from rotary wheel encoders. Feature-based VO relies on detecting feature points, such as corners or edges, in image frames as the vehicle moves. These points are tracked over frames and, as a group, estimate motion. Not all detected points are tracked since not all are found in the next frame. Even tracked features may not be correct since a feature point may map to an incorrect nearby feature point. This can depend on the driving scenario, which can include driving at high speed or in the rain or snow. This article investigates the effect of image structural content on the performance of feature tracking

Aladem, Mohamed, Baek, Stan, Rawashdeh, Samir A., Rawashdeh, Nathir A.

Time-Dependent Reliability-Based Design Optimization of Vibratory Systems

2017-01-019403/28/2017

A methodology for time-dependent reliability-based design optimization of vibratory systems with random parameters under stationary excitation is presented. The time-dependent probability of failure is computed using an integral equation which involves up-crossing and joint up-crossing rates. The total probability theorem addresses the presence of the system random parameters and a sparse grid quadrature method calculates the integral of the total probability theorem efficiently. The sensitivity derivatives of the time-dependent probability of failure with respect to the design variables are computed using finite differences. The Modified Combined Approximations (MCA) reanalysis method is used to reduce the overall computational cost from repeated evaluations of the system frequency response or equivalently impulse response function. The method is applied to the shape optimization of a vehicle frame under stochastic loading. The novelty of the proposed work lies in the integration of

Papadimitriou, Dimitrios, Mourelatos, Zissimos, Patil, Santosh

Strength Analysis of Motocrosser Frame on Jump-Landing

2016-32-002911/08/2016

One of the issues when developing motocrossers is that, when a motocrosser jumps and lands, the landing applies heavy loads on various parts of the bike, particularly the frame, and produces high stresses. This sometimes causes deformation, cracks, breakage, etc. during strength tests on actual bikes, and it takes much time and money to check the effects and develop solutions. To solve this problem, we have developed a method for simulating the jump-landing of motocrossers.

Suzuki, Shohei

Full Instrumentation of Side Impact Pole and In-Depth Analysis of Vehicle Structural Behavior

2016-36-012810/25/2016

In order to obtain more information from the side impact tests, a pole was fully instrumented with triaxle load cells. Also, a sled modification was carried out providing a sub-frame view of the vehicle during the entire test and making possible to compare the structure and element deformations with the obtained data. An in-depth analysis of vehicle structural behavior focused on the forces received by the vehicle during the pole side impact test was made. A crash test was set to validate the acquisition system of the instrumented pole. The obtained data like the forces and the deformations were analyzed in depth and used for a structural study of the vehicle. The data acquired by the acquisition system was used to obtain a force diagram from the pole and a comparison was made with the vehicle absorption mechanisms and structural elements involved. Moreover, the force data was compared with the sub-frame view and with the structural element’s deformation. With the results, it was

Sanchez, Jacob, Malivern, Melcior, Parera, Núria, Fornells, Alba

Safety Release Fasteners Enable New Cabin/Cargo Decompression Concept

2016-01-208209/27/2016

In the frame of incremental product improvement, AIRBUS has developed and implemented a new innovative rapid decompression / pressure relieve concept for the cargo compartment area. The core change lays with detaching the complete cargo lining panels from the substructure in case of a rapid decompression in the cargo area instead of using dedicated blow in panels. In that way, pressure equilibrium can be achieved by air flow through the opened areas around the cargo lining panels rather than through specific blow out / blow in venting areas. The key for this is a self-detaching fastener AIRBUS has developed in an outstanding cooperation with ARCONIC Fastening Systems & Rings (former Alcoa Fastening Systems & Rings) in Kelkheim, Germany. These fasteners are installed to keep the cargo lining panels in place and tight against smoke in case of fire which is one of the main purposes for their use. In case of a rapid decompression event in the cargo area, the multi-piece self-detaching

Schomaker, Ralf, Knickrehm, Björn, Langediers, Jürgen

Crushing Analysis and Lightweight Design of Tapered Tailor Welded Hybrid Material Tubes under Oblique Impact

2016-01-040704/05/2016

The increasing demand for lightweight design of the whole vehicle has raised critical weight reduction targets for crash components such as front rails without deteriorating their crash performances. To this end the last few years have witnessed a huge growth in vehicle body structures featuring hybrid materials including steel and aluminum alloys. In this work, a type of tapered tailor-welded tube (TTWT) made of steel and aluminum alloy hybrid materials was proposed to maximize the specific energy absorption (SEA) and to minimize the peak crushing force (PCF) in an oblique crash scenario. The hybrid tube was found to be more robust than the single material tubes under oblique impacts using validated finite element (FE) models. Compared with the aluminum alloy tube and the steel tube, the hybrid tube can increase the SEA by 46.3% and 86.7%, respectively, under an impact angle of 30°. Parameter analyses were performed to reveal the influence of four geometrical variables on the

Wang, Da-Zhi, Cao, Guang-Jun, Qi, Chang, Sun, Yong, Yang, Shu, Du, Yu

Uncertainty Optimization of Thin-walled Beam Crashworthiness Based on Approximate Model with Step Encryption Technology

2016-01-040404/05/2016

Crashworthiness is one of the most important performances of vehicles, and the front rails are the main crash energy absorption parts during the frontal crashing process. In this paper, the front rail was simplified to a thin-walled beam with a cross section of single-hat which was made of steel and aluminum. And the two boards of it were connected by riveting without rivets. In order to optimize its crashworthiness, the thickness (t), radius (R) and the rivet spacing (d) were selected as three design variables, and its specific energy absorption was the objective while the average impact force was the constraint. Considering the error of manufacturing and measurements, the parameters σs and Et of the steel were selected as the uncertainty variables to improve the design reliability. The algorithm IP-GA and the approximate model-RBF (Radial Basis Function) were applied in this nonlinear uncertainty optimization. In order to improve the accuracy of the RBF model, a new step-encryption

Du, Qianqian

Locating Wire Short Fault for In-Vehicle Controller Area Network with Resistance Estimation Approach

2016-01-006504/05/2016

Wire shorts on an in-vehicle controller area network (CAN) impact the communication between electrical control units (ECUs), and negatively affects the vehicle control. The fault, especially the intermittent fault, is difficult to locate. In this paper, an equivalent circuit model for in-vehicle CAN bus is developed under the wire short fault scenario. The bus resistance is estimated and a resistance-distance mapping approach is proposed to locate the fault. The proposed approach is implemented in an Arduino-based embedded system and validated on a vehicle frame. The experimental results are promising. The approach presented in this paper may reduce trouble shooting time for CAN wire short faults and may enable early detection before the customer is inconvenienced.

Du, Xinyu, Jiang, Shengbing, Nagose, Atul, Zhang, Yilu, Wienckowski, Natalie

Dynamic Modeling and Simulation Analysis of Interconnected Air Suspension System

2016-01-044204/05/2016

Interconnected air suspension system can change a vehicle’s operation characteristics by exchanging gas between air springs. In this paper, we analyze the structure and working principle of interconnected air suspension based on thermodynamics and vehicle dynamics. Then air suspension’s mathematical model including interconnected characteristics is established to study gas exchange principle of air suspension system. Interconnected pipeline parameters and excitation phase differences’ influence on characteristics of air suspension system in whole vehicle are calculated and analyzed. Simulation results show that the stiffness of air suspension is reduced when air springs of the suspension system are interconnected, as well as it decreases gradually with the increase of interconnected pipeline diameter; the stiffness of air springs is minimum if the excitation phase difference between both sides of air springs is 180 degrees. In the condition of twist pavement (tires at diagonal

Xu, Xing, Nannan, Zou

Influence of Frame Stiffness on Heavy Truck Ride

2016-01-044904/05/2016

The stiffness of the frame has a great influence on the ride comfort of the heavy truck. Reducing frame thickness was proved to be unacceptable in terms of ride comfort, which is verified by the testing results. The truck frame was reinforced in order to improve the ride comfort. The modal analysis showed that the pitch frequency of the vehicle has increased 0.5 Hz and the frequency response has decreased by 20%. In order to research the influence of frame stiffness on the heavy truck ride comfort, a detailed model including a flex frame, chassis suspension, cab suspension, driveline, etc., was built by MSC.ADAMS. The Simulation results showed that the ride comfort can be improved by reinforce the frame, and the ride comfort can be improved by 5%∼10%. The results of this study need to be further examined through field testing.

Xu, Xian, Chen, Wei, Cao, Yuan, Zhang, Yingxiong, Guo, Hu

Jeep will test pickup concepts at Moab 50th

16AUTP04_1104/01/2016

Military vehicle strength, functionality, and styling underscore two Jeep-based concept trucks that took on the challenging off-road trails of Moab, Utah, during the recent annual Jeep Safari. “It's a very, very important event this year because it's the 50th anniversary of the Easter Jeep Safari, and it's coinciding with the 75th anniversary of Jeep,” asserted Mike Manley, Head of Jeep Brand for FCA Global.

Buchholz, Kami

2016 Civic structure employs ‘first’ partial in-die soft zones

16MEIP03_1503/01/2016

The 2016 Honda Civic employs selectively-tempered in-die “soft zone” technology in the B-pillars and rear frame rails, allowing zones within a single frame piece to have more ductile properties than the surrounding ultra-high-strength hot-stamped steel. The technology minimizes parts count and saves 15.6 lb (7 kg) compared to the previous-generation Civic. “Our method of application for this [in the rear frame rail] is a world's first,” according to Ryan Miller, Performance Development Leader for the 2016 Civic. “Full-band soft zones [such as in the B-pillar] have been done before on a few other cars, but what we've done that's unique is we've created partial soft zones; this is much more difficult to do.”

Gehm, Ryan

Lighter, more powerful 2016 Honda Pilot

15AUTP10_0210/01/2015

The third-generation SUV gets a sleek new look and plenty of slick technology for enhanced performance and safety. Programs for new re-engineered vehicles pose a great challenge for the engineers and other professionals assigned to them: load the vehicle with more advanced technology, consumer-friendly amenities, and safety features required to meet stringent requirements, all while trimming weight from any area necessary to maintain-or ideally decrease-overall weight compared to the previous generation. The 2016 Honda Pilot development team, faced with said challenge, succeeded brilliantly. The new three-row SUV is 289 lb (131 kg) lighter-the previous Pilot Touring weighed 4632 lb (2101 kg) vs. the new Pilot Elite, which includes more features but weighs 4343 lb (1970 kg)-while recently earning a 2015 Top Safety Pick+ rating from the Insurance Institute for Highway Safety (IIHS).

Gehm, Ryan

Loads Comparison: Rigid x Flex Truck Mutibody Model

2015-36-041509/22/2015

Vehicle durability mission loads are an essential and decisive for a reliable life prediction for the component through any durability evaluation. One option to calculate mission loads are multibody models to represent vehicle’s suspension degrees of freedom (dofs) and its dynamic behavior. Generally, trucks have greater wheelbase and then lower natural frequencies than passengers’ vehicles. Therefore are more suitable to dynamic body excitation and the ordinary consideration of a rigid body shell is not relevant. The proposal of this work is to compare the chassis loads considering rigid and flexible frame mounted over the primary suspension. A pseudo-damage was calculated with chassis loads time history for severity assessment. The chose vehicle for the study is an Iveco 4×2 medium range, 6850mm of wheel base, with gross weight of 17ton and leaf springs primary suspension on both: front and rear axles.

Coutinho, I., Vales, L. F., Vimieiro, C. B. S.

System for Recirculation of Mobile Tooling

2015-01-249409/15/2015

Aircraft assembly systems which require tooling or machinery to pulse or move between multiple positions within a factory can be positioned with high repeatability without high performance foundations or sweeping out large areas of floorspace. An example shows a system of large left and right-hand frames which are positioned at 3 sequential manufacturing steps and then recirculated to the start of production via a central return aisle. The frames are 41 ton actual weight and are 72′ long, similar to a rail car. The system achieves rectangular motion for the recirculation path. The supporting and moving system incorporates low-cost rail in a floor with minimal preparation and simple to use controls. The system is also easily reconfigured if the manufacturing system needs to be altered to meet rate or flow requirements.

Hempstead, Benjamen D., Smith, Scott

Direct Multiple Shooting Optimization with Variable Problem Parameters

TBMG-22871

09/01/2015

Solving complex trajectory problems optimally is of vital importance to the success of future aerospace programs. Trajectory optimization research has been divided into two main categories: indirect methods and direct methods. Both methodologies have been tested and extensively applied to specific orbital trajectory problems.

Data Server for Real-Time Display Interface

TBMG-22869

09/01/2015

The purpose of this software is to decouple display and data interface functions by developing a central data server. By using the centralized data server, flight displays can be easily transferred between simulators and research airplanes without having to reprogram flight display graphics. Therefore, to drive flight displays, only a single software interface needs to be written to communicate with the data server. Further, the interface to the server has the ability to add and remove variables from the data server in real-time. This allows for great flexibility in the use of the data server. This design allows data to be centrally recorded and played back on the flight deck displays for later analysis by researchers.

Dynamic Stiffness Estimation of Elastomeric Mounts Using OPAX in an AWD Monocoque SUV

2015-01-219006/15/2015

Mount development and optimization plays an important role in the NVH refinement of vehicle as they significantly influence overall driving experience. Dynamic stiffness is a key parameter that directly affects the mount performance. Conventional dynamic stiffness evaluation techniques are cumbersome and time consuming. The dynamic stiffness of mount depends on the magnitude of load, frequency of application and the working displacement. The above parameters would be far different in the test conditions under which the mounts are normally tested when compared to operating conditions. Hence there is need to find the dynamic stiffness of mounts in actual vehicle operating conditions. In this paper, the dynamic stiffness of elastomeric mounts is estimated by using a modified matrix inversion technique popularly termed as operational path analysis with exogenous inputs (OPAX). The test vehicle is an all-wheel drive (AWD) monocoque vehicle which has power train in east-west configuration

Rao, Manchi Venkateswara, Moorthy, S Nataraja, Raghavendran, Prasath

Motion Blur Evaluation Techniques

TBMG-22183

06/01/2015

Motion blur results when a moving edge travels across a display, such as a liquid crystal display (LCD), that has limited temporal response. It is important to be able to quantify this effect in visual terms. The techniques described in this work provide methods for estimating the strength of the motion blur artifact in perceptual units of JNDs (just noticeable differences).

Mechanics of Brake Steering Pull on Heavy Trucks

2015-36-002405/13/2015

Heavy trucks with solid front axles commonly use steering systems that have left to right asymmetry. The asymmetry creates the potential to cause steering pulls during brake application which are by their nature undesirable since they require an input in the steering wheel by the driver to maintain the correct path of the vehicle. Brake forces acting in the tire contact patches create toe-out moments around the kingpin axes that are resisted by the steering linkages. However asymmetry of the linkage allows unbalanced toe-out steer angle deviations at the wheels resulting in a path deviation of the truck that is perceived as brake steering pull. The factors influencing steering pull include the compliance properties of the steering linkages, road wheel geometry, drag link geometry and spring windup properties. The mechanics of the brake force interactions with these steering and suspension properties are explained here. Simulation provides an excellent tool to examine and quantify these

Gillespie, Thomas, de A. Lima, Vinicius

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