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The responses of a Hybrid III 5th percentile dummy manufactured by Denton ATD were compared to a Hybrid III 5th percentile dummy manufactured by First Technology Safety Systems (FTSS). The dummies were seated on a HYGE sled set in a representative small production sedan configuration, simulating a 60 km/h offset deformable barrier (25 g pulse) and a 22 km/h crash (11 g pulse). Three shoulder retractor anchorage positions were used to place the shoulder belt at different locations on the dummy shoulder for each of the driver (left shoulder) and passenger (right shoulder) seating positions. Chest deflections measured from the rotary potentiometer are compared to deflections calculated from the accelerometers and are reported as a function of belt load and belt position. Repeatability is evaluated at low and high deflection levels.

Despite the general similarity of U.S. and European heavy trucks, there are differences in design properties that affect braking and turning performance. A European tractor-semitrailer was studied for the purpose of comparing its properties to those of U.S. vehicles and assessing the comparative performance. Mass, suspension, and braking system properties of the European tractor and semitrailer were measured in the laboratory and on the proving ground. Turning and braking performance qualities were evaluated by computer simulation and by experimental tests. In turning performance the European combination had a 9 percent advantage in rollover threshold, compared to a generic U.S. vehicle with properties that were in the midrange of U.S. design practice. Higher suspension roll stiffness and higher chassis weight on the European tractor and semitrailer accounted for the higher threshold.

This research compares vehicle dynamic simulations in PC-Crash 8.2 to data recorded during instrumented handling tests conducted by Mechanical Systems Analysis Incorporated (MSAI). The handling tests, which were used to examine rollover stability in a 1998 and a 1999 Ford Explorer, involve rapid steering inputs at speeds between 30 mph [48.3 kph] and 60 mph 96.6 [kph]. Vehicle weight, center of gravity (c.g) position, suspension stiffness parameters, tire parameters, steering angle, and vehicle speed data provided by MSAI were used as input for the PC-Crash model. Lateral acceleration, roll angle, roll rate, and yaw rate vehicle response from PC-Crash were compared to the MSAI sensor data. The authors modeled 26 handling tests. PC-Crash appeared to be a reasonable tool for modeling gross vehicle response. In addition, PC-Crash correctly predicted whether or not the test vehicle would experience rollover instability in a majority of the cases.

The aim of the study was to investigate the difference between car-to-e-bikes and car-to-pedestrian accidents. The China In-depth Accident Study (CIDAS) database was searched from 2011 to 2013 for pedestrians and e-bikes struck by car, van and SUV fronts, which resulted in 104 pedestrian and 85 e-bike cases where information was sufficient for in-depth analysis. Reconstruction by PC-Crash was performed for all of the sampled cases. Pre-crash parameters were calculated by a MATLAB code. Focus was on prototypical accident scenarios and causes; speed as well as possible prevention countermeasures. It has been shown that traffic light violations, road priority violations, and unsure safety (these situations included misjudgments, unpreparedness, proximity to other road users, inappropriate speeds, etc.…) are the main causes in both the VRU groups. Distinctions were found for aspects of car collision speed, accident scenario, distribution of head contact points and so on.

The discernment of whether a tire mark on a roadway is the result of a skidding tire or is the result of the rotation of the vehicle with unlocked wheels is important in vehicular accident reconstruction analysis. Resolution of the tire marks left by a vehicle after skidding and/or yawing on dry asphalt were experimentally studied for their similarities and differences under controlled test conditions. This paper analyses the results of this study and shows pictorially the differences for use by the accident reconstructionist. Analytical discussion are also presented that illustrate speed determination as estimated from yaw markings on the roadway.

Vehicle traffic accidents have been extensively studied in various countries, but any differences in traffic accidents the studied areas have not yet been adequately investigated. This paper aims to make a comparison study of head injury risks and kinematics of adult pedestrian accidents in Changsha, China, and Hannover, Germany, as well as correlate calculated physical parameters with injuries observed in real-world accidents of the two cities. A total of 20 passenger cars versus adult pedestrian accidents were collected from the two areas of study, including 10 cases from Changsha and 10 cases from Hannover. Virtual accident reconstructions using PC-Crash and MADYMO software were performed. The in-depth study focused on head injury risks while kinematics were conducted using statistical approaches. The results of the analysis of the Chinese data were compared with those of the German data.

Evaluation of vehicle impacts may involve the use of computer simulations. While simulation programs with two-dimensional impact models have been used for decades, more recent three-dimensional impact models have been developed. This research compares DyMESH, the three-dimensional vehicle impact model in HVE-SIMON, with full-scale vehicle crash tests involving low-speed rear impacts. Exponent Failure Analysis Associates (Phoenix, Arizona) conducted rear impact research involving two virtually identical 1983 Nissan Pulsar NX 2-door vehicles. One vehicle was stationary, while the second vehicle impacted the rear of the first vehicle in an aligned configuration. Tests were run at impact speeds ranging from 5 to 20 MPH. Tri-axial accelerometers were positioned in both vehicles and vehicle acceleration and velocity responses were recorded. SIMON-DyMESH was used to simulate these impact tests. DyMESH utilizes a mesh shell determined by the three-dimensional geometry of the vehicle.

This paper presents the results of a test program comparing the performance of the CAUSFIX (originally known as CANFIX) and the Uniform Child Restraint Anchorage (UCRA) systems to the conventional Australian anchorage system of adult belt and top tether. Each anchorage configuration was subjected to both 45 and 90 degree simulated side impacts. The performance of the attachment systems was assessed using the TNO P3/4 dummy in both a rearward facing restraint and a forward facing restraint. Assessment was based on peak head acceleration and displacement. The results indicate that both the CAUSFIX and the UCRA system can provide improved protection for children in side impacts. The CAUSFIX system was found to offer the greatest potential for improvement. The results of this work are significant to the current debate concerning the proposed draft international standard for universal anchorage systems.

Martinez and Schlueter [6] described a three-phase model for reconstructing tripped rollover crashes, where the vehicle's path is divided into pre-trip, trip, and post-trip phases. Brach and Brach [9] also described this model and noted that the trajectory segmentation method for the pre-trip phase needed further validation. When a vehicle leaves a measurable yaw mark at the start of its pre-trip phase it might be possible to compare estimates from the three-phase model to those obtained using the critical speed method, and this paper describes Bayesian reconstruction of two such cases. For the first, the 95 percent confidence interval for the case vehicle's initial speed, estimated using the critical speed method, was (64 mph, 81 mph) while the 95 percent confidence interval via the three-phase model was (66 mph, 79 mph).

Collision warning systems (CWS) are a relatively new technology to reduce or mitigate motor vehicle rear-end and side impact collisions. This study compared available police-reported crash experiences of 6,143 CWS-equipped heavy trucks with the experiences of 383,058 heavy trucks without CWS. Data were from the Motor Carrier Management Information System (2000-2002). Results suggest that CWS-equipped trucks had a significantly lower proportion of crashes involving other moving vehicles and a significantly lower proportion of multiple vehicle crashes compared to trucks without CWS, (40% vs. 49%, p<0.0001; 62% vs. 67%, p<0.004 respectively). These changes are the first crash-data based evidence that supports the design effect of CWS. However, more studies are needed to determine the specific impacts of CWS on heavy truck crashes.

The CRASH3 computer program models a vehicle structure as a homogeneous body with linear force-deflection characteristics. Crush stiffness coefficients determined from full-overlap crash tests, when used in this computer program, allow for an accurate reconstruction of collisions where the accident damage profiles are full-overlap. In the past, partial-overlap frontal crash tests were not performed. The lack of partial-overlap frontal crash tests meant that a reconstructionist only had crush stiffness coefficients available that were determined from full-overlap frontal crash tests. In a reconstruction, the assignment of stiffness coefficients to a partial-overlap damage profile required engineering judgement. Often the basis of such judgement was questioned because of the lack of supporting partial-overlap test data. Recently partial-overlap crash tests have been performed and the test data has been made available to the public.

The results of an empirical study comparing the deceleration performance characteristics of several passenger cars is presented. Three definitions of average coefficient of friction are developed and utilized as a basis for comparison of the performance of the vehicles. In addition, the percent energy dissipation before skid mark initiation for each vehicle is also presented and compared. The interpretation of skid marks utilizing a site specific skid test with a dissimilar vehicle is then discussed from the perspective of accident reconstruction.

European and American side impact research efforts are directed toward the realization of further increases in existing levels of passive safety. Because side impact accident experience here and abroad exhibits many similarities, governments of the European community and the United States should cooperate and agree on a common test procedure including common test devices and test parameters. Within this context, Volkwagen studied the deformable side impact barriers presently under discussion in the United States and Europe. The results of this comparative study are presented. In addition to this comparison, the comparative evaluations of dummies and human subjects by the German Research Association for Automobile Technology (Forschungsvereinigung Automobiltechnik-(FAT)) as well as the Thoracic Trauma Index (TTI) developed by NHTSA are discussed.

Frontal crashes and near-side crashes were compared and found to be significantly different events. In a frontal crash, the energy to be dissipated from the occupant is constant for a given speed. In a side crash, the energy transferred to a struck-side occupant depends highly on his interaction with the door. That difference has important implications on the choice of countermeasures, injury criteria, and subsystem tests. In a frontal crash, chest and abdominal injuries occur in the “second” impact when the occupant, acting like a free-flight mass, strikes the interior. Padding can absorb some of the free-flight energy, reduce the impact force, and provide earlier and longer contact of the occupant with the interior. The earlier contact decreases the differential velocity of the occupant to the interior, and the longer contact allows more time and greater distance to dissipate the kinetic energy.

Ground-based Light Detection and Ranging (LiDAR) using FARO Focus 3D scanners (and other brands of scanners) are repeatedly shown to accurately capture the geometry of accident scenes, accident vehicles, and exemplar vehicles, as well as corresponding evidence from these sources such as roadway gouge marks, vehicle crush depth, debris fields, and burn areas. However, ground-based scanners require expensive and large equipment on-site, as well as other materials that may be required depending on the scenario, such as tripods and alignment spheres. New technologies, such as Apple’s mobile phone LiDAR capture, were released recently for their newer model phones, and these devices offer a way to obtain LiDAR data but with less cumbersome and less expensive equipment. This mobile LiDAR can be captured using many different applications from the App Store which can then be exported into point cloud data.

Light detection ranging (LiDAR) is commonly used to make high-resolution maps by using ultraviolet, visible, or near-infrared light to image objects. It can target a wide range of materials, with many applications, such as in surveying and accident reconstruction. LiDAR-like systems combine laser-focused imaging with the ability to calculate distances by measuring the time for a signal to return using various electronic sensors. LiDAR data capturing has been conducted and verified from many types of equipment manufacturers, however, little research has compared the FARO Terrestrial Laser Scanner and the LiDAR sensor of an iPad Pro. This study compares these two types of equipment addressing ease-of-use, effectiveness, and cost; where the Terrestrial Laser Scanner will be the control for this study. A statistical evaluation was performed of LiDAR data acquired from nine damaged vehicles and one undamaged vehicle.

For several staged collisions, results obtained with closed form reconstruction calculations and with a computerized step-by-step procedure are compared with measured responses. A refined, closed-form reconstruction procedure is defined, derivations of the analytical relationships are outlined and detailed results of sample applications are presented. Closed form calculation procedures for estimating impact conditions became a topic of interest in relation to the development of an automatic starting routine for iterative applications of the Simulation Model of Automobile Collisions (SMAC) computer program. The accuracy of initial estimates of speeds determines the total number of iterative adjustments of SMAC that are required to achieve an acceptable overall match of the evidence. Since a high degree of success was achieved in the refinement of such calculation procedures, the end product, by itself, is considered to be a valuable aid to accident investigations.

The evaluation of a rollover accident requires the assessment of a large amount of information in order to completely analyze the accident and determine the vehicle dynamics throughout its roll sequence. This information includes the physical evidence available through examination of the accident site, the vehicle and any photographs or documentation of the accident scene. Many times there is a lack of scene data available complicating a thorough evaluation of the vehicle path and roll distance during the rollover. Inspection of the vehicle reveals the minimum number of rolls the vehicle experienced during the rollover event, leaving the roll distance traveled as one of the many unknown variables. This paper compares the roll distance, roll speed and number of rolls for dolly testing and real world rollovers. An evaluation of the roll distance and number of rolls for passenger cars, light trucks and sport utility vehicles is compiled and compared to one another.

The WorldSID dummy can be equipped with both a pubic and a sacroiliac joint (S-I joint) loadcell. Although a pubic force criterion and the associated injury risk curve are currently available and used in regulation (ECE95, FMVSS214), as of today injury mechanisms, injury criteria, and injury assessment reference values are not available for the sacroiliac joint itself. The aim of this study was to investigate the sacroiliac joint injury mechanism. Three configurations were identified from full-scale car crashes conducted with the WorldSID 50th percentile male where the force passing through the pubis in all three tests was approximately 1500 N while the sacroiliac Fy / Mx peak values were 4500 N / 50 Nm, 2400 N / 130 Nm, and 5300 N / 150 Nm, respectively. These tests were reproduced using a 150 kg guided probe impacting Post Mortem Human Subjects (PMHS) at 8 m/s, 5.4 m/s and 7.5 m/s.

This paper summarizes a series of matched-pair frontal sled tests using the Test device for Human Occupant Restraint 50th Percentile Male (THOR-50M) anthropomorphic test device (ATD). Testing was conducted to compare the response of an ATD equipped with an on-board data acquisition system (DAS) to that of one equipped with an off-board system. Sled testing was performed using a modified version of NHTSA’s Gold-Standard test method consisting of a generic buck with a ridged seat and a 3-point seatbelt system. Eight tests were conducted, all using a common generic 30 km/h crash pulse with a peak deceleration of 9 G’s, and a 2.5 kN load limiting 3-point seatbelt retractors without pretentioners. Four tests were conducted with each ATD, two tests with a left shoulder belt routing and two with a right shoulder belt routing to allow for evaluation of the ATD repeatability under each belt routing.