Frontal Crash Simulation Research Articles

Biomechanical Impact Response of the Human Chin and Manubrium

Chin-to-chest impact commonly occurs in frontal crash simulations with restrained anthropomorphic test devices (ATDs) in non-airbag situations. This study investigated the biofidelity of this contact by evaluating the impact response of both the chin and manubrium of adult post-mortem human subjects (PMHSs). The adult PMHS data were scaled to a 10-year-old (YO) human size and then compared with the Hybrid III 10YO child (HIII-10C) ATD response with the same test configurations. For both the chin and manubrium, the responses of the scaled PMHS had different characteristics than the HIII-10C ATD responses. Elevated energy impact tests to the PMHS mandible provided a mean injury tolerance value for chin impact force. Chin contact forces in the HIII-10C ATD were calculated in previously conducted HYGE sled crash simulation tests, and these contact forces were strongly correlated with the Head Injury Criterion (HIC(36 ms)). The mean injurious force from the PMHS tests corresponded to a HIC(36 ms) value that would predict an elevated injury risk if it is assumed that fractures of the chin and skull are similarly correlated with HIC(36 ms). Given the rarity of same occupant-induced chin injury in booster-seated occupants in real crash data and the disparity in chin and manubrium stiffnesses between scaled PMHS and HIII-10C ATD, the data from this study can be made use of to improve biofidelity of chin-to-manubrium contact in ATDs.

Numerical studies concerning upper neck and head responses in frontal crashes with seat-integrated safety belts

Mitigation of neck and head injuries is critical in automotive occupant protection. The aim of the present study is to investigate how the physical properties influence the interaction of the seat back frame and the safety belt. Seat integrated 3- and 4-point configurations with both non-rigid and rigid seat back frames were compared with 3-point configurations with anchor points on the car body. The LS-DYNA FE-analysis software was used in order to perform frontal crash simulations with a belted 50th percentile Hybrid III dummy model as occupant. The belt-webbing distribution between the lap and the torso belts via a slip-ring and in combination with a non-rigid seat back frame had an advantageous influence concerning the loads of the upper neck and injury criteria compared to a system with no belt-webbing distribution.

Modelling and simulation of seat-integrated safety belts including studies of pelvis and torso responses in frontal crashes

The aim of the present study is to investigate how the physical properties influence the interaction of the seat back frame and the safety belt. Seat-integrated 3- and 4-point configurations with both non-rigid and rigid seat back frames were compared with common 3-point configurations with anchor points on the car body. The LS-DYNA FE-analysis software was used in order to perform frontal crash simulations with a belted 50th percentile Hybrid III FE-dummy model as occupant. The belt-webbing distribution between the lap and the torso belts via a slip-ring and in combination with a non-rigid seat back frame increases the ride-down efficiency compared to a system with no belt-webbing distribution. No tendencies of pelvis submarining were observed regardless of belt configuration. The dynamic response of the seat back frame has some influence on the ride-down efficiency.

Study on Structural Lightweight Design of Automotive Front Side Rail Based on Response Surface Method

Nowadays, vehicle lightweight design is a main topic in automotive industry. Crashworthiness, which is the most important performance of a full vehicle, must be always satisfied in the study on body lightweight design. This paper presents research, from the point of view of safety, of structural lightweight design of the front side rail of a passenger car. The response surface method is used to create mathematical models that represent the relationship between structural sheet thicknesses and absorbed energy of the entire structure in the frontal crash simulation, and the relationship between structural sheet thicknesses and the mass of the entire structure. Then an optimization process is performed, and the structural mass and original absorbed energy are defined as objective and constraint functions, respectively. Minimum mass and structural sheet thicknesses are obtained with the satisfaction of original absorbed energy of the front side rail structure. The weight reduction of the front side rail is 26.95%.

Improvement of energy-absorbing structures of a commercial vehicle for crashworthiness using finite element method

This paper describes the results of the frontal crash simulation of a commercial vehicle using the nonlinear finite element method. The dynamic responses of the vehicle during the frontal crash at 48.3 km/h and 8 km/h are presented. In the developing stage of the design the structure of the front longitudinal beam is optimized, hence the amount of energy absorbed increases greatly. In the test stage of the whole vehicle, the data of the simulation predict that the hinge of the engine hood would fracture during the crash. This fact has also been validated by the test. The failure of the engine hood hinge would be a danger to both the driver and the passengers. So, according to the simulation, the structure and material of the engine hood and hinge are modified. As a result the deformation mode of the engine hood is improved accordingly.