Browse Topic: Accident types

Items (1,068)

Feasibility of Road Longitudinal Profiles for Automated Vehicles Based on Vehicle Dynamics

2025-01-715003/19/2025

With the development and maturity of new generation digital technologies such as artificial intelligence, Internet of Things, and 5G mobile communication, their integration with physical products is becoming increasingly seamless. Automobiles serve as a prime example in this regard. In recent years, automated vehicle (AV) technologies have emerged as a prominent focal point, witnessing an escalating acceptance in the market and a growing number of self-driving vehicles on the roads, existing roads are primarily designed for traditional human-driven vehicles (HVs). Due to the differences in perception between automated systems and human drivers, it is essential to assess AVs' feasibility to current road infrastructure. This paper analyzes the safety and comfort of automated vehicles equipped with adaptive cruise control systems (ACC-AVs) on longitudinal road profiles from the perspective of vehicle dynamics. Firstly, a co-simulation platform integrating PreScan, CarSim, and Simulink

Li, Zezhou, Cai, Mingmao, Gu, Tianqi, Yu, Bin

Effectiveness of the Load Legs in Enhancing the Passive Safety of Rear-Facing Child Seats in Frontal Crash

2024-26-034301/16/2024

The passive safety performance of a child seat is modulated by the design features of the child seat and the vehicle interior. For example, in the rear-facing configuration, the child seat impacting front structures increases the head injury risk during a frontal crash. Therefore, this study evaluates the effectiveness of the load leg countermeasure in improving the child seat's overall kinematics and its capability to prevent the secondary impact on the vehicle interior structure in a severe frontal crash scenario. An in-depth, real-world crash investigation involving a properly installed rear-facing child seat impacting the center console is selected for the study where the infant sustained a severe brain injury. In addition, this crash is employed to choose the crash parameters for evaluating the effectiveness of the load leg countermeasure in a similar scenario. Finally, crash sled tests are conducted using the crash signature of the vehicle as obtained from the NHTSA NCAP rigid

Thorbole, Chandrashekhar

Seatback Failures and Human Tolerance in Severe Rear Impacts

2024-26-000301/16/2024

Seatback and head restraints is the primary restraining device in rear-impact collisions. The seatback failures expose front seat occupants to dive deep into the rear compartment survival space. Furthermore, it allows the occupants to get in a position with lower spinal tolerance to the impact direction. This paper employs sled tests to demonstrate the dangers of seatback failures in severe rear impact by allowing the occupants to orient their spine in its lowest tolerance zone to the impact direction. Furthermore, the sled test shows the potential of head pocketing phenomena and torso augmentation producing compressive cervical spine loading enough to cause first-order neck buckling. Finally, the results of collapsing seatback dynamics are compared to the strong seatback performance by conducting a similar test with a strong ABTS seatback. The study demonstrates that the strong seatbacks in severe rear impacts produce favorable outcomes while keeping the occupant in their higher

Thorbole, Chandrashekhar

Child Injury Pattern and Mechanism Differences Based on the Front Seat Occupancy Status in Rear Impacts with Severe Structural Intrusions from the Rear

2024-26-000501/16/2024

Child crash injury protection in severe rear impact chiefly depends on how well the rear survival space bounded by the vehicle structure is maintained. Previous research and studies have shown the ill effects of front seatback collapse intruding into the rear child survival space from the front with minor or no intrusions from the rear. This paper shows the child injury pattern and fatal injury mechanism for a rear impact crash with a severe compartment intrusion from the rear without any front seat occupant. Furthermore, it compares the injury outcome with a similar crash and severe intrusion in the presence of the front occupant employing a full-scale vehicle-to-vehicle crash test. A detailed real-world crash investigation is conducted to identify the injury mechanism. It is compared with the outcome of similar severity rear impact vehicle-to-vehicle crash tests producing different injury patterns. The comparison and the analysis show that the survival space intrusion due to safety

Thorbole, Chandrashekhar

RAMP BRACKET ANGLE OPTIMIZATION COUPLED WITH IMPROVED HEAD ROOM

2024-26-001601/16/2024

Restraint systems in automotives are inevitable for the safety of passengers. Curtain airbag is one such restraint system in automotives that reduces the risk of injury to passengers during crash, without which head injury is inevitable during side crash of a vehicle. So successful deployment of Curtain airbag (henceforth called as CAB) is very important in automotive safety during crash. This paper dwells about the optimization done in ramp bracket angle with successful deployment of Curtain airbag. This optimization has paved the way for increasing the head-roominess by ~15% and to respect the safety and styling intent in the vehicle successfully. Providing a ramp bracket at the lower bottom side of CAB guides the airbag successfully during deployment. Ramp bracket angle plays a vital role in guiding the airbag inside the passenger’s cabin without any obstruction. This paper challenges the conventional ramp bracket angle followed for CAB deployment with an alternate angle and has

D, GOWTHAM, L, DHARSHAN, bornare, harshad, RITESH, KAKADE, Deoli, Manish, BHASKARARAO, PATHIVADA, GANGAPURAM, SURESH, Kakani, Phani Kumar

Importance of Pole Side Impact Test for Assessment of Curtain Airbags

2024-26-001901/16/2024

Government of India, in 2017, mandated a Side Impact Test (AIS 099 technically aligned to UN ECE Regulation No. 95.03 series of amendments) on M1 category Passenger Vehicles to ensure protection of occupants in lateral impact accident scenarios. Later, in 2022, a draft notification has been issued by the Government mandating installation of 6 airbags (2 No.of thorax side airbags, 2 No. of head protection or curtain airbags in addition to already mandated installation of Driver and Passenger Airbags) in all such passenger vehicles. However, the vehicles fitted with side thorax airbag and curtain airbags are proposed to be assessed as per AIS099 test only. Curtain Airbags are typically installed to protect occupant’s head from severe injuries in narrow object impacts simulated in Pole Side Impact Test Configurations. However, at present, India has not notified an equivalent standard to UN R135 demanding performance of the vehicle in pole side impact scenarios. Typically, OEMs may need to

Jaju, Divyan, Kulkarni, Dileep, Mahindrakar, Rahul, Mahajan, Rahul

Occupant Injury Severity Prediction in Road Traffic Accidents using Machine Learning Techniques

2024-26-001101/16/2024

Over years, automotive industry has made a significant progress in improving passenger car safety systems to reduce occupant injuries and fatalities due to road accidents. To further enhance the vehicle safety, it is very important to have a deeper understanding on real world accidents and true safety benefits associated with various safety systems. This requires a framework to understand the effectiveness of safety systems towards reduction in occupant injury and fatalities. This study focusses on utilizing machine learning techniques to predict occupant injury severity by considering accident parameters and safety systems, using the Road Accident Sampling System - India (RASSI) real world accident data. The RASSI database contains comprehensive accident data, including various factors that contributes for occupant injury. The study focused on fifteen accident parameters that represent key aspects of crash scenarios such as vehicle type, accident type, vehicle speed, and occupant

G, Santhosh Kumar, Khatavkar, Akshay, Sahu, Dilip, Koralla, Sivaprasad, Kulkarni, Prasad

PERFORMANCE OF FIVE-POINT SEAT BELT ON OCCUPANT SAFETY IN VEHICLE ON FRONTAL CRASH TEST

2022-28-049311/18/2022

In day-to-day life, accidents do occur frequently all-round the globe. It is difficult to prevent these accidents as they occur due to different reasons, which cannot be easily controlled. But the fatal injuries occurring to passengers can be reduced by installing safety systems in vehicles, which will help in saving the life of mankind. There are many safety systems being installed in vehicles such as seat belt restraints, air bags etc. Generally, three-point seat belts are installed in passenger vehicles for safety purposes. This type of seat belt doesn't arrest the entire motion of the occupant body during vehicle crashes, which can lead to fatal injuries and sometimes even death during vehicle crashes. In order to buckle passengers with seats, we can use five-point seat belts which will help in mitigating the injuries as compared to three-point seat belts. In this paper, we evaluate the performance of five-point seat belts on occupant safety during vehicle crash on flat rigid

Jeyakumar, P, CHANDRAN, DINESHKUMAR

A Study of High Refinement Simulation Prediction on the CAB Development for FMVSS226 Ejection Mitigation Performance

2022-01-092203/29/2022

In the side impact crash accident, the curtain airbag (CAB) plays a significant role in the occupant head protection. With the increasing of the rollover accidents, the CAB development is requested to be able to protect the occupant head throughout the whole rollover accident, and to ensure that the occupant head is not partially or totally ejected from the vehicle. NHTSA released the FMVSS226 Standard in 2011, defined the requirements for ejection mitigation systems, which limits the linear travel of headform by 100mm. In China regulations, there are similar requirements starting in 2021. The difference is that it can be replaced by meeting the pressure holding requirements of 6s (up to 50% of the average pressure of 40-70ms). Therefore, on the basis of the existing airbag design, adding the rollover protection function becomes a new challenge for the airbag development. During the development of the curtain airbag, the cushion design, inflator type, and the fold pattern, all have an

Shan, Jinhui, Xue, Lele, Wang, Cheng

Injury Severity Prediction Algorithm of SUBARU Fleet Model for Advanced Automatic Collison Notification

2022-01-100503/29/2022

Recently, with the evolution of telemetry technology in vehicles, Advanced Automatic Collision Notification (AACN) that detects patients at risk of serious injury in the event of an accident and transports them to the trauma center at an early stage may greatly improve the treatment of patients. An Injury Severity Prediction (ISP) algorithm for AACN was developed using a logistic regression model to predict the probability of sustaining Injury Severity Score (ISS) 15+ injury. National Automotive Sampling System Crashworthiness Data System (NASS-CDS: 1999-2015) and model year 2000 or later were filtered for new case selection criteria, which were based on vehicle body type, to match Subaru’s fleet. This proposed algorithm uses crash direction, change in velocity, multiple impacts, seat belt use, vehicle type, presence of any older occupant, presence of any female occupant, and presence of the right-sided passenger. Variable selection techniques were used to construct the final ISP

Ejima, Susumu, Goto, Tsukasa, Zhang, Peng, Cunningham, Kristen, Wang, Stewart

Assessment of fetus injury risk during vehicle frontal impact for different lap belt positions

2022-01-102203/29/2022

The paper addresses vehicle safety for pregnant drivers and passengers. The influence of the different positions of the lap part of the seat belt for pregnant female drivers and passengers on the injury risk is assessed. The finite element based pregnant abdomen model is incorporated into the simplified validated rigid body based female body model. The pregnant female model is positioned into a frontal seat and restrained by a safety system such as three-point seat belt and an airbag to simulate the sled test scenario. The deceleration pulse corresponding to a frontal impact related to two impact velocities is applied and the restraint system performance is assessed with focus on the fetus and female injury risk. The uterus is modelled via so called biobag and mechanical loading and injury risk of this particular part and adjacent structures are the main concern of this study.

Spicka, Jan, Hyncik, Ludek, Jansova, Magdalena, Talimian, Abbas

Rear-End Impacts – Part 2: Sled Pulse Effect on Front-Seat Occupant Responses

2022-01-103903/29/2022

This study was conducted to assess the effects of differing rear impact pulse characteristics on restraint performance, front-seat occupant kinematics, biomechanical responses, and seat yielding. Five rear sled tests were conducted at 40 km/h using a modern seat. The sled buck was representative of a mid-sized driver environment in a generic sport utility vehicle. The peak acceleration, acceleration shape and duration were varied. Three of the pulses were selected based on published information and two were calculated to assess the effects of long and short initial acceleration rate using a trapezoidal characteristic shape. The angle at maximum seatback rearward deformation varied from 26 to 47 degrees. It was lowest in Pulse 1 which simulates an 80 km/h car-to-car rear impact. The seatback plastic deformation was greater in the pulse with a long initial acceleration rate, Pulse 4, than in the short acceleration rate, Pulse 5 (28 degrees v 22 degrees). Coincidingly, the longitudinal

Parenteau, Chantal, White, Samuel, Burnett, Roger

Structural design of a full-body composite monocoque chassis based on the type of carbon fiber fabrics

2022-01-044403/29/2022

The number of stacked layup and orientation of carbon fiber/epoxy in a sandwich panel with the aluminum honeycomb core was optimized using finite element method (FEM) to improve the structural performance of the monocoque chassis for the electric Formula SAE (FSAE) racecar. To establish the selection criteria for fabrics and orientations, the single unidirectional (UD) and woven plies (W) were simulated under tensile and simple shear tests to determine their off and on-axis properties. Simulation results revealed that the unidirectional ply enhances the overall strength of laminate while woven ply is responsible for shear strength. Thus, the combination of unidirectional and woven plies was proposed. The four anisotropic laminates consisting of four plies with different orientations were simulated under three-point bending and plate twist tests to determine the flexural rigidity and twist stiffness (D66), respectively, and their mechanical properties were compared to the quasi

Sratong-on, Pimpet

Development of a Variable Stiffness Seatback

2022-01-103703/29/2022

A challenge faced by the automotive industry is to optimize the stiffness of seat structures such that in rear-impact collisions, seatback deflection is compliant enough to adequately absorb impact energy, yet stiff enough to prevent excess deformation. While comprising a smaller percentage of all automotive accidents, severe and fatal injuries occur in rear impact crashes. Injuries to front seat passengers can be mitigated in some crashes with stiffer seatbacks, and in other crashes with more yielding seatbacks, depending on the accident severity and other factors. In rare cases, injuries to rear seat passengers occur when front seats deform and intrude into rear occupant spaces. There has existed a debate for years regarding whether seats should be manufactured increasingly stiffer, or more yielding. Compounding the problem are additional factors including widely varying crash severities, impact angles, out-of-position occupants, intermittent use of rear seating areas, etc

Warner, Mark H., Warner, Wyatt

Using Artificial Intelligence to Determine the Speed Change of Frontal Collisions

2022-01-099803/29/2022

The speed change (Delta-V) sustained by a vehicle during a collision is a key element in many traffic collision investigations. Accident reconstructionists have a variety of investigation techniques that can be used to estimate speed change including crush energy, momentum based simulations and event data recorders. This paper proposes that artificial intelligence can be used to analyze photos of damaged vehicles in order to estimate the speed change. An artificial intelligence model was trained using images from over 1000 investigations of frontal collisions (the training set). The resulting model was tested using images from a new set of 250 frontal collision investigations (the test set). In about 85% of the test set, the resulting model predicted the speed change to within ±5mph of the original collision investigation results. By adopting artificial intelligence based algorithms, the accident reconstruction community can gain an additional check on their speed change calculations

Rollover and near-rollover kinematics during evasive steer maneuvers

2022-01-104203/29/2022

We present 6-degree-of-freedom (6DOF) kinematic data from two SUVs during evasive steer maneuvers that did and did not result in rollovers. The vehicles were instrumented with a GPS speed sensor, tri-axial accelerometers, tri-axial angular rate sensors, and a steering wheel angle sensor. Drone-based and land-based video cameras recorded all tests. Six degree of freedom position/orientation data were extracted from the video using match moving techniques with 3D constraints from laser scans of the test site and vehicles as described in our previous SAE paper (SAE 2020-01-0272). The initial speeds varied from 100 to 124 km/h and the steering input during the tests were similar. We examine the magnitude and timing of the vehicle pre-roll kinematics to identify differences between the roll and non-roll events. We also present the 6DOF kinematics of the rollovers themselves. This study provides valuable insight into factors that predict roll initiation during evasive steer maneuvers.

Young, Cole, King, David, Siegmund, Gunter

Injury by Delta V in Front, Near-Side, Far-Side and Rear Impacts: Analysis of 1994-2015 NASS-CDS

2022-01-100803/29/2022

The risk for severe injury (MAIS 4+F) was determined by crash type, seatbelt use and crash severity (delta V) using 22 years of NASS-CDS from 1994-2015 with all light vehicles and occupants 15+ years old. There were 9 increments of delta V from <16-72+ km/h (<10-45+ mph). Crashes were grouped by the location of damage to the front, near-side, far-side and rear. Injury risk was calculated by dividing the number of severely injured (MAIS 4+F) by the number of exposure (MAIS 0+F) occupants using weighted data. Standard errors were determined. The data and plots provide a national estimate of injury by delta V in front, near-side, far-side and rear impacts based on the most recent field data in NASS-CDS.

Viano, David, Parenteau, Chantal

Seatback Strength and its Effect on In Position and Out of Position ATD Loading in High-Speed Rear Impact Sled Tests

2022-01-103803/29/2022

Vehicle rear structure stiffness has increased as a result of the requirements in the FMVSS 301R, which has also corresponded to an increase in front-row seat strength. This study evaluates the structural behavior and occupant response associated with production-level seats equipped with body-mounted D-rings, and very stiff all-belt-to-seat (ABTS) in a group of 12 deceleration sled tests. A double-haversine approximately 100-msec duration pulse was used for all tests, with peak accelerations of approximately 19 g for the 40 km/h (25 mph) tests and peak accelerations of 28 g for the 56 km/h (35 mph) test. This pulse was designed to represent a severe rear impact crash involving modern vehicles. The tests compared occupant responses and resulting structural deformation of an original equipment manufacturer (OEM) production-level driver seat from a pickup and a very stiff modified ABTS. Both seating systems were equipped with dual recliners. Various combinations of tests evaluated the

Croteau, Jeffrey, Toney-Bolger, Megan, Isaacs, Jessica L., Shurtz, Ben, Zolock, John

Second-Row Children Fatalities in Front and Rear Crashes

2022-01-103603/29/2022

Objective: The protection of children in the second row in automotive crashes remains an important area of safety research. Field data is analyzed on second-row children in front and rear crashes to study fatality trends in 1980-2020 model-year vehicles and to investigate the safety improvements with higher head restraints, stronger front seats and increased use of restraint systems. Methods: 1990 to 2019 FARS was queried to assess the number of fatally injured second-row children (0-15 years old). The children included outboard occupants seated behind an occupied front seat and center occupants. The data was analyzed for rear and frontal crashes by calendar and model year. Results: The number of child fatalities decreased by calendar years and model years. There were 2.95-times more fatally injured children in frontal crashes than in the rear crashes. The relative risk decreased with MY (model year) of the vehicle. For example, it was 3.6-times higher in 1990-1999 MY vehicles and 2.3

Parenteau, Chantal, Viano, David, Lau, edmund

Investigations of Honeycomb and Foam structures of Automotive Front rails During Frontal crashes and its affinity with Optimum Energy Absorption

2022-01-104903/29/2022

Energy dissipation in frontal crash of the vehicles normally occurs through the deformation in the engine compartment zone and especially on longitudinal front rails. In this article, the details of the crash tests is presented which involves an interpretation of the damage profiles and understanding the origin of the stiffness coefficients in main particular member which is front rails of a passenger vehicle. Moreover, the present experimental work is used to estimate the energy dissipated during deformation based on crush measurements. Furthermore, it explains the implementation of experimental test to investigate the influence of design characteristics on the deformation behavior of the proposed front rails. The current experimental work deals with the influences of geometric shape modifications of conventional steel members with flange configurations compared to honeycomb structures and structural foam with the same members length. The observations in this work led to conclude the

Elhussieny, Sayed Abbas, Oraby, Walid

Rear-End Impacts – Part 1: Field and Test Data Analysis of Crash Characteristics

2022-01-104103/29/2022

Prior to developing or modifying the protocol of performance evaluation tests, it is important to identify field relevant conditions. The objective of this study was to assess the distribution of selected crash variables from rear crash field accidents involving modern vehicles. The exposure and serious-to-fatal injury of non-ejected occupants was determined in 2008+ model year (MY) vehicles using 2007-2015 NASS-CDS and 2017-2019 CISS. In addition, 15 EDRs were collected from 2017 to 2019 CISS cases with a rear delta V ranging from 32 to 48 km/h. Ten rear crash tests were also investigated to identifying pulse characteristics in rear crashes. The tests included five vehicle-to-vehicle crash tests and five FMVSS 301R barrier tests matching the struck vehicle. The analysis of NASS-CDS and CISS data indicates that more than 50% of exposed (MAIS 0+F) occupants were involved in a rear crash with a distributed impact and with no over-ride or under-ride. More than 93% were with a 6 o’clock

Parenteau, Chantal, White, Samuel, Burnett, Roger, Stephens, Gregory, Michalski, David

A Study on the Robust Crash Performance Structure of Continuous Fiber Thermoplastic Composite Cowl Crossbar

2022-01-105603/29/2022

Since the 1990s, an increasing amount of research has been done in the automotive industry, not only to improve vehicle production efficiency and performance but also for environmental preservation and enhanced recycling. For this reason, recently, keen interest has been focused on the reduction of fuel consumption through the development of eco-friendly and weight-effective vehicles. This is due in part to the strengthening of regulatory standards for fuel efficiency in each country. This study will focus on the high crash safety performance and the optimization of the IP module, in particular, the cowl crossbar, which in most vehicles, can account for more than 33% of the total weight. In fact, the cowl crossbar is the main part of the vehicle that must support the duct system, steering column module as well as the entire IP module. Therefore, it requires a high stiffness to meet the performance requirements for NVH, durability, and crash protection. For example, during a frontal

Kim, Heeseok, KIM, IL SANG, JAE HYUN, AN, IN SOO, HAN, CHOI, IKKEUN, Park, Sanghyeon

Validation of Utilizing a Self-Propelled Crash Sled to Simulate Occupant Accelerations in Minor Rear-End Impacts

2022-01-104003/29/2022

A novel, electrically self-propelled, mobile, free-standing crash sled was constructed with a relatively minimal budget (i.e., ≤ $10,000). The crash sled was designed to simulate occupant driver or passenger seat movement in minor impacts at varying angles with minimal, if any, component replacement necessary between tests. Validation of the crash sled in a rear-end only configuration for determination of occupant accelerations was performed. Minor rear-end crash tests involving human occupants were conducted utilizing a 2007 Toyota Camry target vehicle and a 2005 Toyota Camry bullet vehicle with changes in velocity for the target vehicle ranging between 2.8 km/h and 7.7 km/h. Vehicle instrumentation consisted of tri-axial accelerometers affixed to the center tunnels near their respective center of gravities. Human occupant instrumentation occurred only in the target vehicle and involved tri-axial accelerometers at the head, thorax, and lumbar spine. Peak longitudinal head and lumbar

Vigil, Cole Mackenzie, Salboro, Conrad, Jones, Brian, Brink, Justin, Jorgensen, Michael, Swinford, Scott

Design and Optimization of an Electric Car Chassis and Body using Structural Analysis and CFD

2022-01-033903/29/2022

The transition from traditional gasoline-powered automobiles to electric vehicles (EVs) has taken time, two major challenges of engine- powered vehicles are greenhouse gas emissions and fuel economy. Electric cars require less maintenance. A lot of money can be saved while also helping the environment. In today's world, working with lightweight materials have emerged as a key area for improvement in the automotive industry. The most efficient method for increasing power output is to reduce the weight of vehicle components. Composite materials have benefited greatly from research and development because they are stronger, more recyclable, and easier to integrate into vehicles. The primary goal of this research is to design the body and chassis frame of a two-seater electric car. A CFD analysis was performed to determine the drag coefficient of the body along with structural analysis to obtain the frontal impact and torsional rigidity of the chassis to develop an effective electric car

Aiyan, Mohammed, Raghav S, Sanjay, Sagar, S Sumanth

The Role of Three-Point Restraints for Occupants in Moderate and Higher Severity Frontal Impact Collisions

2022-01-102603/29/2022

Field accident data and vehicle crash testing have shown that kinematics, occupant loading, , and associated injury risk generally increase with crash severity. Further, these data demonstrate that the use of restraints, such as three-point belts, provides mitigation of kinematics and reduction in loading and injury rates. This study evaluated the role of seat belts in controlling occupant kinematics and reducing occupant loading in moderate and higher severity frontal collisions. Frontal tests with belted and unbelted anthropomorphic test devices (ATDs) in the driver and right front passenger seats were performed at delta-Vs of approximately 19 kph and 32 kph with no airbag deployment. At the lower severity, the belted ATDs’ motion was primarily arrested by seat belt engagement, mitigating contact with forward vehicle structures, while the unbelted ATDs’ motion was largely arrested by interaction with forward vehicle structures. Injury metrics were generally lower with belt use than

Isaacs, Jessica L., George, Juff, Campolettano, Eamon, Cutcliffe, Hattie, Miller, Bruce

Reconstruction of an auto-rickshaw frontal crash using FE simulation with validation using captured crash video from India

2021-28-025710/01/2021

The three wheeled “Auto-Rickshaws” [Auto] plays a significant role in road transportation, especially in India. The crash safety and reconstruction studies have been widely used in four wheelers, whereas the availability of such data for Auto was found to be limited. In recent times, accident data processing from available videos is being utilised to observe the crash scenario, from which the crash parameters can be given as inputs to the crash analysis. This paper focusses on process the real-world accident data and study crash characteristics. With limitation in availability of detailed injuries post-crash, the study was restricted to reconstruction of crash kinematics and estimations of indicative injuries to driver. The source of video data is videos of crash available in public domains like YouTube. PYTHON video processing tool has been used to process the set of real-world accident video data. The object detection, Pixel per meter computation and object tracking are the major

S, Ragul, Sankarasubramanian, Hariharan, Kondaveeti, N S V Nikas, Yadav, Pandugayala Nithin

Engineering challenges in Alloy wheel rim for safety simulations

2021-26-036209/22/2021

Aluminium alloy wheels are widely used in the automotive industry over the last decade due to its superior styling and performance. Alloy wheel rim is one of the critical components and plays an important role in a frontal crash scenario. Alloy wheel rim failure prediction in safety simulation is essential to ensure robust safety performance. Determining failure characteristics of an alloy wheel poses many difficulties considering its brittle nature, porosity and inhomogeneity in material properties across different regions of wheel rim due to mould design, cooling rate and other process parameters of the low-pressure die casting process. This paper describes the modelling and simulation methodology developed to predict accurate wheel behaviour. The methodology addresses two distinct areas of challenges such as alloy wheel rim failure prediction and associated tire blow out. Alloy wheel rim material was characterised considering the inhomogeneity of material properties at different

Koralla, Sivaprasad, Tiwari, Sourabh, Khare, Pratyush, Daphal, Pratap, Gese, Helmut

Assessment of the 50th Hybrid III Responses in Blunt Rear Impacts to the Torso

2021-01-091904/06/2021

Blunt impacts to the back of the torso can occur in vehicle crashes due to interaction with unrestrained occupants, or cargo in frontal crashes, or intrusion in rear crashes, for example. Six pendulum tests were conducted on the back of an instrumented 50th percentile male Hybrid III ATD (Anthropomorphic Test Device) to determine kinematic and biomechanical responses. The impact locations were centered with the top of a 15-cm diameter impactor at the T1 or at T6 level of the thoracic spine. The impact speed varied from 16 to 24 km/h. Two 24 km/h tests were conducted at the T1 level and showed repeatability of setup and ATD responses. The 16 and 24 km/h tests at T1 and T6 were compared. Results indicated greater head rotation, neck extension moments and neck shear forces at T1 level impacts. For example, lower neck extension was 2.6 times and 3.8 times greater at T1 versus T6 impacts at 16 and 24 km/h, respectively. A 24 km/h test at T1 was also conducted with a seatback attached to the

Buckman, Jennifer L., Parenteau, Chantal S., Burnett, Roger, Viano, David C., Andrecovich, Christopher

Pedestrian Impact Analysis of Side-Swipe and Minor Overlap Conditions

2021-01-088104/06/2021

This paper presents analyses of 21real-world pedestrian versus vehicle collisions that were video recorded from vehicle dash mounted cameras or surveillance cameras. These pedestrian collisions have in common an impact configuration where the pedestrian was at the side of the vehicle, or with a minimal overlap at the front corner of the vehicle (less than one foot overlap). These impacts would not be considered frontal impacts [1], and as a result determining the speed of the vehicle by existing methods that incorporate the pedestrian travel distance post impact, or by assessing vehicle damage, would not be applicable. This research examined the specific interaction of non-frontal, side-impact, and minimal overlap pedestrian impact configurations to assess the relationship between the speed of the vehicle at impact, the motion of the pedestrian before and after impact, and the associated post impact travel distances. The21analyzed events are categorized according to the type of impact

Neale, William T., Danaher, David, Donaldson, Andrew, Smith, Tegan

A Comparative Life Cycle Assessment of Magnesium Front End Autoparts: A Revision to 2010-01-0275

SAE-PP-0018501/29/2021

The Magnesium Front End Research and Development (MFERD) project under the sponsorship of Canada, China, and USA aims to develop key technologies and a knowledge base for increased use of magnesium in automobiles. The primary goal of this life cycle assessment (LCA) study is to compare the energy and potential environmental impacts of advanced magnesium based front end parts of a North American-built 2007 GM-Cadillac CTS using the current steel structure as a baseline. An aluminium front end is also considered as an alternate light structure scenario. A “cradle-to-grave” LCA is conducted by including primary material production, semi-fabrication production, autoparts manufacturing and assembly, transportation, use phase, and end-of-life processing of autoparts. This LCA study was done in compliance with international standards ISO 14040:2006 [1] and ISO 14044:2006 [2]. While weight savings result in reductions of energy use and climate change emissions during the use phase of the car

Mutagaana, Festo

Occupant Restraint Dynamic System Evaluation - Frontal Impact Heavy Trucks

J2418_202011 (Current)

11/09/2020

This SAE Recommended Practice describes the test procedures for conducting frontal impact restraint tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.

Truck Crashworthiness Committee

Articulated Vehicle Lateral Stability Management via Active Rear-Wheel Steering of Tractor Using Fuzzy Logic and Model Predictive Control

07/01/2020

In-phase rear-wheel steering, where rear wheels are steered in the same direction of front wheels, has been widely investigated in the literature for vehicle stability improvements along with stability control systems. Much faster response can be achieved by steering the rear wheels automatically during an obstacle avoidance maneuver without applying the brakes where safe stopping distance is not available. Sudden lane change movements still remain challenging for heavy articulated vehicles, such as tractor and semitrailer combinations, particularly on roads with low coefficient of adhesion. Different lateral accelerations acting on tractor and semi-trailer may cause loss of stability resulting in jackknifing, trailer-swing, rollover, or slip-off. Several attempts have been made in the literature to use active steering of semi-trailer’s rear wheels to prevent jackknifing and rollover. However, loss of stability in an articulated vehicle is usually caused by an oversteered tractor, and

Sahin, Hasan, Akalin, Ozgen

Tesla casts a new strategy for lightweight structures

20AUTP06_0106/01/2020

The EV maker boldly invests in the world's largest aluminum die-casting machine to manufacture entire rear underbody structures. Aluminum is synonymous with “weight-saving” in most contemporary automotive-engineering reference points. But apart from a few applications - most notably Ford's F-Series pickups - aluminum largely is deployed where steel can be readily displaced without performance loss or for comparatively small components that deliver comparatively small weight or process savings. Electric-vehicle maker Tesla is readying the next step in aluminum use, however - one that effectively matches Ford's “big gain” approach by specifying a massive piece of structural die-cast aluminum for the rear underbody of the recently launched Model Y crossover. According to Tesla CEO Elon Musk, this new aluminum application represents a radical step for its design and manufacturing advantages and its light-weighting potential. Musk is renowned for outsized promises, but in the case of the

Innovative Active Head Restraint System in a Car: Safety Assessment with Virtual Human Body Model

2020-01-097904/14/2020

The aim of this study is to use numerical simulations for safety assessment of an innovative active head restraint system. This system was developed to protect the head and neck of an occupant in a car without a head airbag during a side impact. Its FE model is created and embedded it in a model of a small car with a side airbag. The dynamics of the head restraint activation are also taken into account. The virtual human body model Virthuman is used to represent occupants. The model is scaled for pre-selected human individuals to cover large numbers of occupants of different sizes. It extends conventional virtual evaluation of new safety designs via existing pre-defined mono-purpose side dummies and their FE models. The benefit of the head restraint system is evaluated in side impact scenarios inspired by the pole tests performed by EuroNCAP. Transversal impacts to a pole at 29 and 32 km/h are considered at 90° and 75° angles from driver and the opposite side. Also, the far side impact

Vychytil, Jan, Hlucha, Jana, Kovar, Ludek, Kostikova, Martina, Moravcova, Pavlina, Bucsuhazy, Katerina

Evaluation of General Motors Event Data Recorder Performance in Semi-Trailer Rear Underride Collisions

2020-01-132804/14/2020

The objective of this study was to analyze the validity of airbag control module data in semi-trailer rear underride collisions. These impacts involve unusual collision dynamics, including long crash pulses and minimal bumper engagement [1]. For this study, publicly available data from 16 semi-trailer underride guard crash tests performed by the Insurance Institute for Highway Safety (IIHS) were used to form conclusions about the accuracy of General Motors airbag control module (ACM) delta-V (ΔV) data in a semi-trailer rear underride scenario. These tests all utilized a 2009 or 2010 Chevrolet Malibu impacting a stationary 48’ or 53’ semi-trailer at a speed of 35 mph. Nine tests were fully overlapped collisions, six were 30% overlapped, and one was 50% overlapped [2]. The IIHS test vehicles were equipped with calibrated 10000 Hz accelerometer units. Event Data Recorder (EDR) data imaged post-accident from the test vehicles were compared to the reference IIHS data. For each test, root

Famiglietti, Nicholas, Hoang, Ryan, Fatzinger, Edward, Landerville, Jon

A Novel Prediction Algorithm for Heavy Vehicles System Rollover Risk Based on Failure Probability Analysis and SVM Empirical Model

2020-01-070104/14/2020

The study of heavy vehicles rollover prediction, especially in algorithm-based heavy vehicles active safety control for improving road handling, is a challenging task for the heavy vehicle industry. Due to the high fatality rate caused by vehicle rollover, how to precisely and effectively predict the rollover of heavy vehicles became a hot topic in both academia and industry. Because of the strong non-linear characteristics of Human-Vehicle-Road interaction and the uncertainty of modeling, the traditional deterministic method cannot predict the rollover hazard of heavy vehicles accurately. To deal with the above issues, this paper applies a probability method of uncertainty to the design of a dynamic rollover prediction algorithm for heavy vehicles and proposes a novel algorithm for predicting the rollover hazard based on the combined empirical model of reliability index and failure probability. Moreover, the paper establishes a classification model of heavy vehicles based on the

Zhu, Tianjun, Yin, Xiaoxuan, Wang, Zhenfeng, Wang, Dong, Li, Fei, Wang, Xinyu, Ma, Wei, Wang, Zheng

Frontal Crash Worthiness Performance of Bitubular Corrugated Conical Structures under both axial and oblique loads at low velocity

2020-01-098304/14/2020

Vehicle collisions are a major concern in the modern automotive industry. To ensure the passenger safety, major focus have been given on energy absorption pattern during collision, which lead to the implementation of new design of the crash box for low speed collision. The main aim of this research is optimization of the conical shaped bitubular structure based on its mean diameter, graded thickness and semi vertical angle. Further to increase energy absorption characteristics of the conical crash box, corrugations are integrated on both tubes and optimized based on different parameters such as number of corrugations, pattern of corrugation relative to both tubes and depth of corrugation. A finite element model is created to perform parametric study on corrugated conical bitubular structure based on axial and oblique load conditions at low velocity. Optimization to maximize total absorbed energy and minimize peak impact load on the crash box within constraints is conducted. The result

Porwal, Akash, Tripathi, Abhishek, Krishnasamy, Prabu

A Human Body Model Study on Restraints for Side-Facing Occupants in Frontal Crashes of an Automated Vehicle

2020-01-098004/14/2020

This study is to investigate kinematics and responses of side-facing seated occupants in frontal crashes of an automated minivan using Global Human Body Models Consortium (GHBMC) simplified occupant models (50th%ile male and 5th%ile female), and to develop new restraint concepts to protect the occupants. The latest GHBMC M50-OS and F05-OS models (version 2.1) were further validated with the Postmortem Human Subject (PMHS) side sled tests [Cavanaugh 1990] and the PMHS far-side sled tests [Formen 2013], with detailed correlations of the kinematics and the injury measures. Robustness and biofidelity of the GHBMC human models, especially for the pelvis and knee body regions, were further improved. Using the improved M50-OS and F05-OS models, we evaluated the body kinematics and injury measures of the side-facing seated occupants in frontal crashes at severities ranging from 15 mph to 35 mph. Three restraint conditions were studied: 1) no restraint; 2) lap belt only; 3) lap belt and

Zhao, Jay Zhijian, Katagiri, Maika, Decker, William, Lee, Sungwoo, Gayzik, Francis

Comparison of Occupant Fatality Factors in Underride Passenger Car Accidents in India and USA

2020-01-098404/14/2020

Underride accidents constitute around 5% and 4% of all accidents in India and the US respectively. Yet, the passenger car occupant fatality risk is the highest in this accident configuration when compared to other configurations. Especially in India, the fatality rate is even higher due to minimal usage of underride protection devices in the front, rear and sides of commercial vehicles. This study specifically aims to compare the factors influencing occupant fatality in the rear underride accident configuration, in India and the US. The influencing factors are identified by performing Principal Component Analysis (PCA), which is a linear feature extraction technique. The accident databases considered for this study are RASSI and NASS-CDS. After querying, a total of 88 cases from RASSI and 202 cases from NASS-CDS were extracted, where a passenger vehicle was involved in a rear underride accident with a commercial vehicle. The relevant variables involved in the rear underride accident

Muthanandam, Muthukumar, Aathresh, B S Vishak Nandan, Penumaka, Avinash, Kalakala, Vijaya Prakash

Methods for quantifying the impact severity of low-speed side impacts at varying angles

2020-01-064104/14/2020

Accurately quantifying the severity of minor vehicle-to-vehicle impacts has commonly been achieved by utilizing the Momentum Energy Restitution (MER) method. A review of the scientific literature revealed investigations assessing the efficacy of the MER method primarily for: 1) inline rear-end impacts, 2) offset rear-end impacts, and 3) side impacts configured with the bullet vehicle striking the target vehicle at an approximate 90° angle. To date, the utility of the MER method has not been examined and readily published for quantifying oblique side impacts. The aim of the current study was to observe the effectiveness of the MER method for predicting the severity of side impacts at varying angles. Data were collected over a sequence of 12 tests with bullet-to-target-vehicle contact angles ranging from approximately 45° to 135° with corresponding impact speeds of approximately 13.7 km/h to 16.4 km/h. Vehicle damage profiles documented after each test allowed for the application of the

Brink, Justin, Swinford, Scott, Furbish, Christopher, Jones, Brian, Welcher, Judson, Anderson, Robert

The Effect of Obesity on Rollover Ejection and Injury Risks

2020-01-121904/14/2020

Obesity rates are increasing among the general population. This study investigates the effect of obesity on ejection and injury risk in rollover crashes through analysis of field accident data contained in the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) database. The study involved front outboard occupants of age 15+ years in 1994+ model year vehicle rollover crashes. Complete and partial ejection risks were first assessed seating location relative to roll direction and belt use. The risk of serious-to-fatal injuries (MAIS 3+F) in non-ejected occupants were then evaluated. Occupants were sorted into two BMI groups, normal (18.5 kg/m2 ≤ BMI <25.0 kg/m2) and obese (BMI ≥30 kg/m2). The overall risk for complete ejection was 2.10% ± 0.43% when near-sided and 2.65% ± 0.63% when far-sided, with a similar risk for both the normal and obese BMI groups. Complete ejection was uncommon for belted occupants with a risk of 0.2% or less for all groups. The risk of

Parenteau, Chantal, Smedley, Janine, Carhart, Michael, Dibb, Alan

The Effect of FMVSS 301R on Vehicle Structure in Rear Impact

2020-01-122604/14/2020

Vehicle structures are designed to manage impact forces and transfer crash energy. With the introduction of new rear impact requirements, the design of rear structures has evolved and the use of high strength steel has increased. This study objective was to assess the effect of new FMVSS 301 requirements on vehicle responses. NHTSA conducted 33 offset rear crash tests at 80 km/h with vehicles that pre-dated the newer FMVSS 301R requirements and 86 with vehicles that complied with the newer requirements, with a 2009-2015 model year range. The vehicles were grouped by size and the crush was tabulated. Overall, the struck-side maximum crush decreased in the newer model vehicles. Seven matches with pre and post 301R were identified based on make and model. The matched tests were reconstructed using video analysis and crush measurements of both the barrier and vehicle. Generalized vehicle stiffness was determined for each of the matched tests and indicated that vehicles generally became

Parenteau, Chantal, Stephens, Gregory, Yaek, Jennifer, Gregory, Serge

Update on Second-Row Children Responses in Rear and Frontal Crashes with a Focus on the Potential Effect of Stiffening Front Seat Structures

2020-01-121504/14/2020

The protection of children in rear seats is an important issue, but it is a more complex than assessing front seat performance in rear impacts. 1997–2015 NASS-CDS data were analyzed to estimate the distribution and risk of seriously-to-fatally (MAIS 3+F) injured 0-7 year old children in the 2nd row by crash types with 1994+ model year vehicles. The results showed that children were frequently injured in frontal (39.3%) and in side (27.2%) crashes. The injury risk was highest in rollover (1.72% ± 0.36) followed by rear crashes (0.75% ± 0.56%). Individual rear and frontal impact cases were also reviewed to better understand injury mechanisms of children in the 2nd row. The cases were downloaded and reviewed. There were 15 injured children involved in 14 rear impact crashes. Half were associated with significant intrusion (12+ inches) intrusion of their seating area, pushing the child forward. More than half (7 out of 11 cases with known information) of the front seatbacks remained in

Parenteau, Chantal, Viano, David

Investigating Combined Thoracic Loading Using the Elderly Female Dummy (EFD)

2019-22-001703/31/2020

The Elderly Female Dummy (EFD) is an omni-directional ATD developed to represent a vulnerable population. The EFD it is able to be 3D printed and quickly altered to meet design requirements. A recent side impact sled test series suggested that small, elderly females may be at risk of thoracic injuries in side impact crashes due to combined loading from the belt pre-tensioner and side airbag. The EFD was altered to add four IR-TRACCs to the thoracic region to allow both x-axis and y-axis displacement to be evaluated in a similar test. While the IR-TRACCs did record the displacement due to combined loading, the rate of displacement and timing of the peak displacements did not match external chestband outputs. The next step for the EFD is to revise the locations of IRTRACCs in the thorax and begin component testing in lateral and frontal directions to improve thoracic biofidelity.

Beebe, Michael, Sullenberger, Kris, Burleigh, Mark, McCarthy, Joe, Bolte IV, John H

Optimization of Braking Strategy for Automatic Emergency Braking System in Vehicle-Pedestrian Accidents

07-12-02-000903/23/2020

Braking strategy is the core of the automatic emergency braking (AEB) system. How to make the braking strategy of the AEB system more suitable for real traffic conditions and more acceptable to drivers is a very important research. This article carries out the braking strategy optimization for the AEB system. From the vehicle-pedestrian accidents collected by the National Automobile Accident In-depth Investigation System (NAIS) of Songjiang Station, this article selects typical cases equipped with event data recorder (EDR) and then analyzes the EDR data. On this basis, the strategy for the optimization of the AEB system is formed. The optimized strategy is simulated in the test scenario specified in the European New Car Assessment Programme (Euro-NCAP) and compared with the real vehicle test results. The result illustrates that the optimized braking strategy is more effective to avoid or mitigate collisions.

Qian, Yubin, Yang, Xueyan, Xiao, Lingyun, Zhu, Yican

Influence Analysis of AEB Two-Wheeler on Passenger Car Impact Two-Wheeler Traffic Accidents in China

2020-01-502302/24/2020

AEB two-wheeler system is an active safety technology which developed for avoiding two-wheeler accidents. With a large number of two wheelers, China needs to conduct research and analysis of this system. In this paper, real traffic accident data in China are used to analyze the possible influence of AEB two-wheeler system on traffic accidents. The paper chooses real passenger car impact two wheeler accidents happen in China, and gets the characteristics of data analysis. Then the paper analysis the influence of AEB system using position data when TTC=3s. According to the analysis, the detection range of 90 meters and the detection angle of 45 degrees can improve the recognition rate of day crossing accident by 17.7%, night crossing accident by 21.5% and longitudinal accident by 38.8%. The paper provides effective support for the development and test of AEB two-wheeler system in China. Car-to-two-wheeler accident AEB two-wheeler system Influence of the accident

Xudong, Li, Xiaowei, Lian, Xingchang, Wang

Seat Performance and Occupant Moving Out of the Shoulder Belt in ABTS (All-Belts-to-Seat) in Rear Impacts

2019-01-103104/02/2019

This study examined occupant and seat responses with ABTS (all-belts-to-seat) in rear end collisions. Some have claimed improved ABTS seat performance and retention in rear impacts than conventional seats. ABTS seats tend to have higher ultimate yield strengths than conventional yielding seats. Most ABTS seats have asymmetric seatback stiffness due to the need for additional structure on one side of the seat to support shoulder belt loads. Many designs use a single-side recliner and single stanchion that anchors the D-ring. This asymmetry results in twisting of the seatback in severe rear impacts. Seatback twist can allow the occupant to move away from the shoulder belt. Rearward pull tests on ABTS seats also demonstrates seatback twisting and in some cases large drops in load during the test. The added strength and stiffness of ABTS seats lead to designs that are vulnerable to sudden force drops from separated parts.

White, Samuel, Viano, David, Burnett, Roger

Lateral and Tangential Accelerations of Left Turning Vehicles from Naturalistic Observations

2019-01-042104/02/2019

When reconstructing collisions involving left turning vehicles at intersections, accident reconstructionists are often required to determine the relative timing and spacing between two vehicles involved in such a collision. This time-space analysis frequently involves determining or prescribing a path and acceleration profile for the left turning vehicle. Although numerous studies have examined the straight-line acceleration of vehicles, only two studies have presented the tangential and lateral acceleration of left turning vehicles. This paper expands on the results of those limited studies and presents a methodology to automatically detect and track vehicles in a video file. The authors made observations of left turning vehicles at three intersections. Each intersection incorporated permissive green turn phases for left turning vehicles. The authors recorded video of left turning vehicles at each intersection from a small unmanned aerial system (sUAS), and that video was analyzed

Carter, Neal, Beier, Steven, Cordero, Rheana

Video-Recorded “Looked-but-Failed-to-See” (LBFTS) Accidents in the Junctions of Hong Kong

2018-01-504901/18/2019

To determine causation and contributory factors of “looked-but-failed-to-see” (LBFTS) junction accidents in which the driver stated that “I did not see the pedestrian,” in-depth studies of 22 such accidents which had taken place in Hong Kong were conducted. The studied crashes were all video recorded by closed-circuit television (CCTV) cameras and/or dashboard cameras. Using the video recordings, these junction accidents were reconstructed at the scenes to determine the drivers’ views of the pedestrians and the sequence of events leading up to each accident. The results of the reconstructions and the police investigations, as well as the testimony of the drivers, were analyzed to identify causation and contributing factors of each accident. Attention error/visual search strategy (41%) and misjudgments of drivers (18%) remain the dominant cause of LBFTS crashes. However, it was found that eight crashes (36%) were attributed to the physical obstructions caused by the A-pillars of the

Cheng, Yuk Ki, Tam, Cheok Ning, Tao, Chi Hang, Tsang, Cheuk Nam

Comparative Responses of the PIPER 6YO Human Body Model and the Q6 ATD for Simulated Frontal and Lateral Impacts

SC18-22-000611/12/2018

Abstract - Adult and pediatric human body models have focused on developing accurate representation of the human body in terms of anthropometry and kinetics/kinematics in correlation with published PMHS (Post-Mortem Human Subjects) data. This study focuses on comparing the PIPER 6-year-old human body finite element (FE) model with a Q6 FE model to generate comparable metrics. The FE models were simulated in a vehicle environment by positioning them on two different child booster seats with a 3-point lap-shoulder belt for frontal and lateral impacts. The overall kinematic response (head excursion) of the PIPER human body model (HBM) mimics the behavior of the Q6 ATD. However, there is a significant difference in the NIJ values between the PIPER HBM and Q6 ATD (minimum reduction of 67% in PIPER HBM). The head-neck complex of the PIPER is seen to be more flexible (minimum reduction of 12% in neck forces and 64% in neck moments) as compared to the Q6.

Sarfare, Shreyas, Maheshwari, Jalaj, Duong, Nhat, Belwadi, Aditya

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