The mechanical properties， microstructures， fatigue properties and fatigue fractures of the conventional C-Mn wheel steels and the low- carbon low- silicon phosphorus/chromium-contained transformation induced plasticity（TRIP）steel were investigated. Results revealed that the new-type TRIP steel possessed similar yield strength ， tensile strength increased by 100~150 MPa and fatigue limit increased by 50~140 MPa，compared with the conventional C-Mn wheel steels. The fatigue limit increased with the increase of the tensile strength. The steel containing ferrite，bainite and retained austenite had a higher fatigue limit than the steel containing ferrite，bainite and pearlite or steel containing ferrite，pearlite and martensite-austenite islands.
To study the durability of a passenger car, this work investigates numerical simulation techniques. The investigations are based on an explicit–implicit approach in which substructure techniques are used to reduce the simulation time, allowing full vehicle dynamic analyses to be performed on a timescale that is difficult or impossible with the conventional finite element model (FEM). The model used here includes all necessary nonlinearities in order to maintain accuracy. All key components of the car structure are modeled with deformable materials. Tire–road interactions are modeled in the explicit package with contact-impact interfaces with arbitrary frictional and geometric properties. Key parameters of the responses of the car driven on six different kinds of test road surfaces are examined and compared with experimental values. It can be concluded that the explicit–implicit co-simulation techniques used here are efficient and accurate enough for engineering purposes. This paper also discusses the limitations of the proposed method and outlines possible improvements for future work.
To better support our new energy vehicles industry further decision, and promote the development of the industry rapidly and healthily, our research group fully research the development situation of domestic new energy vehicle industry, summarize the achievements of China's "12th Five-Year", systemly analysis the impact and effectiveness of the demonstration project and technology innovation project,and further evaluate the maturity level of technology,manufacturing and market.Finally make a pre-judgment of the base on the latest developments and rules.