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The instrument panels are made to meet stiffness requirements and also interior safety regulation such as head impact test. Nowadays, CAE is widely used to predict the test results in advance. However, considering fracture phenomena, the characteristics of material takes a significant role for the simulation of the real tests. In this paper, high speed tensile tests and fracture tests of specimens representing typical stress-states were performed to make a fracture criterion of a plastic material (PC/ABS). The suggested method was validated by comparing simulation with test results.

We performed numerical analyses using an explicit code to evaluate the cumulative impact damage of an automotive front-end bumper during low-speed crash events, as described by CMVSS215. The CMVSS215 regulation consists of a series of test cases for the same parts. To evaluate the crash performance of a bumper, we used a coupled numerical analysis scheme and considered several matters such as the removal of residual vibrations and the evaluation of the bumper back beam recovery. We also used an EWK rupture model in the PAM-CRASH code to improve our damage and fracture estimates. Tensile test experiments were conducted to tune the performance of the EWK rupture model; the resulting material properties and fracture criterion were incorporated into the numerical analyses of the low-speed frontal crash events. The coupled analysis scheme was verified by comparing the output with bumper impact test data.

The tear seam of invisible passenger side airbag door is made on the back of an instrument panel by laser scoring method and it is not shown outside. One of the requirements for the invisible passenger side airbag door is that the airbag module should deploy with no fragmentation at hot, room and cold temperature conditions. In this paper, a section model was developed by detail inspection of tearing phenomena at the laser-scored region. To validate the model, the finite elements of continuous and dot type laser-scored tear seam were built and analyzed in room and cold temperature conditions. Finally, a three-dimensional equivalent shell model was developed and it was proved that the section model and the equivalent shell model could represent well the tearing phenomena of the airbag door. It is expected that the tearing pattern prediction models developed in this study can be used to design the types of laser scoring and the airbag door with the minimum of real deployment tests.

In recent years, products that make use of integrated safety that use the environmental data to optimize occupant restraints have been on the market. Pre-safe system in the integrated safety category is an adaptive and smart protection system that utilizes the occupant information and the monitoring information on the accident prediction. These pre-safe systems need the proper algorithm corresponding to the crash scenario for the crash unavoidable state. Due to the crash scenario categories for the real world accidents is quite various, the development of the algorithm and the occupant protection system to reduce the injury is quite complex and costly. For this reason, a development process for pre-safe related integrated safety systems demands new tools based on the biomechanics to help design and assessment. The virtual development and assessment process with a viewpoint on the efficiency of the restraint development has been developed.

The main role of CAB(side curtain airbag) is to protect the occupant's head in the event of side crash. The updated US NCAP for model year 2010 requires more extended coverage of CAB. It is not only required to cover the 50th%ile driver but also the 5th%ile driver and rear passenger. Although the general safety analysis model using only concerned sub-structure of the vehicle and prescribed structural motion is sufficient to handle frequent jobs, the analysis model with increased efficiency is needed when optimization is to be studied as it requires more runs and the model gets enlarged to consider extended sub-structure. In this study, three types of simplified analysis models are introduced. The first has an impactor which is composed of the head and neck with prescribed translational motions. It only uses the upper parts of the original sub-structure hence the run time is saved by 60∼70%.

Requirements of side curtain airbag have continued to increase. The revised SINCAP, FMVSS-226 ejection mitigation and small overlap of IIHS had added these requirements. To meet all the requirements, high inflator energy and complex cushion shape became necessary. Such situations increased possibility of cushion failure while deploying. Unfortunately, all the design verification tests are usually completed in a relatively latter stage of development and repetitive testing is needed to consider large dispersion of failure probability distribution. Therefore, verification and design improvement by numerical simulation in an early stage are desirable. A simulation method which can verify CAB deployment was developed in this study. The developed method has three distinct features. Firstly, nonlinear fabric materials and membrane finite elements are used to consider fracture of cushion fabric. Secondly, a pre-simulation procedure had been established.

The role of CAB is protecting the passenger's head during rollover and side crash accidents. However, the performance of HIC and ejection mitigation has trade-off relation, so analytical method to satisfy the HIC and ejection mitigation performance are required. In this study, 3 types of CAB were used for ejection mitigation analysis, drop tower analysis and SINCAP MDB analysis. Impactor which has 18kg mass is impacting the CAB as 20KPH velocity at six impact positions for ejection mitigation analysis. In drop tower analysis, impactor which has 9kg mass is impacting the CAB as 17.7KPH velocity. Acceleration value was derived by drop tower analysis and the tendency of HIC was estimated. Motion data of a vehicle structure was inserted to substructure model and the SID-IIS 5%ile female dummy was used for SINCAP MDB analysis. As a result, HIC and acceleration values were derived by MDB analysis.