Abstract
Keywords - Passive Safety, IIHS Side Impact, SID-IIs, Crash Simulator , Spring-Mass Model
Abstract - The importance of improving virtual side impact testing methods is continuously on the increase from the need for reducing both fatal accidents and automotive development costs. This paper describes a study of the reproduction of a side impact in an actual vehicle with a hydraulically powered crash simulator. The reproduction of the side impact with the crash simulator was conducted for SID-IIs by the following steps:
First, the dynamic forces applied to SID-IIs dummy during side impact were analytically determined with a mass-spring mathematical model. The model consists of three parts: shoulder, chest and pelvis. Each of the parts comprises mass, spring and damper. By conducting respective unit tests for shoulder, chest and pelvis, each of parameters regarding spring stiffness and damping coefficient was optimized so that a prediction error in the simulated output with measured test data could be minimized.
Then, with the crash simulator, all three loads applied to the three parts were measured, which were used as input data for the simulation. The chest deflection obtained from simulation results correlated well with the data from cash simulator. The magnitude of spring force was compared with that of damping force. As a result, it was found that the spring force was much larger than the damping force. This means that good reproduction of actual vehicles essentially requires an exact door intrusion displacement.
Finally, according to these findings test conditions for the crash simulator were reestablished and the tests were conducted. The results demonstrate that reproduction performance of the shoulder and chest deflection was satisfactory. Our virtual side impact test methodology successfully proves to be an efficient approach to researching and developing an optimized side airbag and door designs to satisfy different modes of side impacts.