The good integrated steering trapezoid of the commercial vehicle can reduce the running resistance, making the steering portability, and reduce tire wear. According to the Ackerman principle, establish the outer wheel theory and practice angle deviation minimum, which is as objective optimization mathematical model. Optimizing two important parameters of the steering trapezoid arm value and the steering trapezoid arrangement angle by the optimization toolbox of MATLAB. After optimization, the value of the actual the inner wheel angle deviation between the theoretical is smaller, so the steering characteristic has been significantly improved.

In the design of disconnected steering trapezoid, the Fmincon function of MATLAB optimization toolbox is used to optimize its basic parameters. First, establish the optimal mathematical model. Second, obtain wheel angle curve of inside and outside steering by least-squares fitting. Finally, compare the curve with the ideal Ackerman geometric curve to get the optimization parameters of disconnected steering trapezoid. The example of optimized design validated that the actual curve of deflection angle of the both sides of steering wheel was almost close to perfect Ackerman geometry curve, it ensures the steering of wheel do pure rolling in the common conditions, which reduce tire wear

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The diaphragm spring is the key element in modern automobile clutch. Its elastic characteristic affects the overall performance of the clutch. Taking a car as an example, According to the design requirements and characteristics, it was to establish the mathematical model of optimum design of automobile clutch diaphragm spring. It was to optimize the design parameters of the basic structure of the diaphragm spring by using the MATLAB optimization toolbox. It did finite element analysis for the 3D modeling using ANSYS software. The results show that: it can be obtained more reasonably of the diaphragm spring elastic curve by the optimal design, shorten the design cycle, reduce the cost of.

The influence of phase transformation cycle times on the plasticity and microstructure of FeMnSiCrNi alloy was researched in this paper. The results show that phase transformation cycling can significantly improve the plasticity of the alloy. Plasticity is improved with the increase of cycles. The elongation gets to 87.6% after 5 cycles, it increases 150% compared with non-treated. The more cycle times, the grain is smaller. During the inverse transformation the second phase directional precipitation significantly harden austenite and improve the reversibility of stress-induced martensite. Due to interaction of the second phase strengthening and grain refinement, the plasticity and strength of alloy are both increased significantly. This method provides a new way for the realization of transformation superplasticity.