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For cold gas Inflator, high refinement of ultimate pressure load forecast of inflator housing is one key of Inflator development. For inflator housing hydro-burst test ultimate load calculation, nonlinear finite element software for high precision results. At beginning, the material parameters of inflator housing for simulation is correlated. The FEA material model adopts the stress-strain data from uniaxial tensile experiments. Considering the geometrical nonlinearity resulting from large deformation as well as material nonlinearity from plastic hardening, the whole tensile process from tensile deformation to failure of the specimen is simulated. Numerical results show that the simulation is appropriate to predict the entire deformation process, and simulation results of ultimate tensile load, X-shape distribution of concentrated instability zone, the fracture location and inclined angle all agrees with that of test results.

NHTSA released the FMVSS226 Standard in 2011, and defined the requirements for ejection mitigation systems, which limit the linear travel of headform by 100mm. In China regulations, there are similar requirements starting in 2021. Therefore, on the basis of the existing airbag design, adding the rollover protection function becomes a challenge for the airbag development. During the development of the curtain airbag, the cushion design, inflator type, and the fold pattern, all have an important influence on the airbag unfolding direction, the airbag positioning time and the airbag internal pressure, and then significantly affect the occupant protection performance afterwards. In order to reduce the cost and shorten the development time, it is necessary to predict the process of cushion deployment kinematics and the internal pressure of the airbag with high refinement, and based on it to predict and evaluate the FMVSS226 ejection mitigation performance.

Noise signals of the driver’s right ear include those of engine, environment, chassis dynamometer, loaded gears and unloaded gears when they are recorded in full vehicle on chassis dynamometer in semi-anechoic room. Gear rattle noise signals of the driver’s right ear caused by unloaded gear pairs can’t be identified or quantified directly. To solve the problems, relative approaches are used to identify and quantify the gear rattle noise signals. Firstly, the rattle noise signals of the driver’s right ear are filtered by human ear characteristic functions and steady noise signals are extracted by regression and smoothing processes. The noise signals are regressed at 200ms interval in the hearing critical frequency bands and smoothed in the flanking frequencies. Then, the noise relative approaches are obtained by subtracting the steady noise signals from the filtered noise signals, which are the transient noise signals of the unloaded gear pairs inducing the rattle noise.

Generally, the gear rattle noise prediction models are composed of the mass and stiffness elements. The proposals are about the gear inertia or backlash and the shaft inertia or stiffness, but there are many detailed designs in the same inertia, stiffness or backlash conditions. Therefore, these proposals can’t guide detailed designs. These models only investigate the rattle in the rotating degree, and ignore rattle contribution in the radical and axial directions. Those prediction models only consider one or several factors which affect the rattle noise performance. It is difficult to predict the influence of individual factor and multi-factors coupling on the gear rattle noise in a rattle simulation model.

Bracket can be reinforced through laying out beads without increasing its thickness, resulting in a lower material cost. To get the optimal layout of bracket beads, beads parameters are discussed through a typical design case. The ways of specifying bead parameters are given, such as beads height and width, by calculating and optimizing geometric parameters of bead section. Then, topography optimization has been applied to get the bracket beads layout. Designers can get the best bracket beads layout through topography optimization software. For improving the first natural frequency of an automotive DVD bracket assembly as an example, the detailed topography optimization process is described and the beads of the DVD bracket are laid out through the method. After being optimized, the first natural frequency of the DVD bracket assembly is increased 30%.

The thermal design requirements at transient state condition are becoming progressively more common in automotive electronic products specifications. For studying the characteristics of heatsink design and CFD thermal analysis in transient state environment, the theories about heat transfer at transient state condition are researched. Some key factors heavily affecting the thermal performance of heatsink are discussed, such as the thickness of heatsink base, the processes of heatsink surfaces and the intervals definitions of whole computation duration in transient state thermal simulation. Then some conclusions of those factors are summarized. Lastly, for an automotive amplifier heatsink design as example, those conclusions are studied and described further based on the correlation of test and analysis results.