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The highway guardrail is the last secure defense which can protect the driver and passenger safety and make the vehicles along the original correct direction when out of control. Collision simulation between vehicle and semi-rigid waveform beam guardrail was achieved. Collision model was given and dimension optimization of the semi-rigid waveform beam guardrail was completed. Dynamic explicit finite element method was applied to simulate and analyze collision process. Optimized height of the lower beam and thickness of the upper and lower beams were obtained, which helped save material, solve the tripping phenomenon and increase safety property of the highway guardrail.

Multi-objective optimization method was adopted for obtaining appropriate dimensions of a new type of inner support in tire. Based on optimized inner support in tire with three monomer block components, finite element models were established by HyperMesh, and dynamic simulation on safety property was completed on LsDyna3D. For this type of inner support in tire, strength is enough during tire burst. After fatigue damage analysis, safety property of inner support after tire burst is well enough too. It is certain for the inner support to work well not only during tire burst but also after tire burst.

EPDM rubber was exposed to an accelerated thermal aging environment produced by an air-circulating oven. The changes of morphology, mechanical properties of EPDM were monitored by scanning electron microscope (SEM), tensile/compressive testing. Crosslink density of EPDM was measured by the solvent swell method. The results showed that many cracks and voids appeared on the surface of EPDM with the exposure time. The aging process proceeded predominantly via crosslinking. The tensile strength increased with increase in crosslink density up to a maximum and thereafter decreased with further increase in crosslink density.

Ethylene propylene diene monomer (EPDM) rubber was exposed to an accelerated thermal aging environment produced by an air-circulating oven for different time periods. The changes of thermal stability and chemical structures of EPDM were monitored by thermo-gravimetric analysis (TGA), Attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) and X-ray Photoelectron Spectroscopy (XPS). The results showed that the accelerated thermal aging environment did not obviously affect the thermal stability of EPDM. FTIR and XPS confirmed the formation of hydroxyl, carbonyl and ester groups in the test environment.

Using the resistively shunted junction model, we study the magnetic field induced dynamic melting transitions of a current-driven vortex system in two-dimensional weakly disordered Josephson junction arrays at zero temperature. From the unified model simulations, we find that the intrinsic quantum vortex liquid (QVL) phenomenon, which consistent with the recent experimental reports in disordered and superconducting MoGe films. The enhancement of critical current in the QVL phase arises from intrinsic quantum fluctuations in the moving vortex flow.

Adopted the load-structure model to tunnel structure design calculation, our country often use surrounding rock pressure experience calculation formula, This paper analysed the problems existing in the experience calculation formula and calculated the surrounding rock pressure have influence on calculation results of tunnel structure internal force with the formulas, and at last given out more actual modification formula, the surrounding rock stress is continuity with the formula calculated, it is more actual than the traditional experience formula, provided a new way for accurate calculated the surrounding rock pressure.

Analyze the role of tunnel lining structure calculation for the elastic resistance, and point out the influence of assuming elastic resistance of Budd-chiarieva method on calculation result and its shortages. Then put forward a new calculation method — Iterative method which can accurately determine elastic resistance distribution law of curved wall tunnel, and introduce basic idea, influencing factor of elastic resistance distribution law, practical method of Iterative method, and the method of improving iterative speed, and the process for calculating internal force of structure is given using Iterative method; contract the calculation results of internal force of structure by Iterative method and Budd-chiari eva method and point out the differences by practical calculation examples. Finally, the application scope of iterative method and necessity for further study are suggested.