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Chopped carbon fiber sheet molding compound (SMC) material is a promising material for mass-production lightweight vehicle components. However, the experimental characterization of SMC material property is a challenging task and needs to be further investigated. There now exist two ASTM standards (ASTM D7078/D7078M and ASTM D5379/D5379M) for characterizing the shear properties of composite materials. However, it is still not clear which standard is more suitable for SMC material characterization. In this work, a comparative study is conducted by performing two independent Digital Image Correlation (DIC) shear tests following the two standards, respectively. The results show that ASTM D5379/D5379M is not appropriate for testing SMC materials. Moreover, the failure mode of these samples indicates that the failure is caused by the additional moment raised by the improper design of the fixture.

The double-V micro-structures (DVMS) are a type of auxetic materials showing the negative Poisson’s ratio which can contract under compression different from the conventional materials. Due to the unique properties, it can have higher stiffness and better impact resistance with lightweight. In this paper, a cylindrical honeycomb tube based on the double-V unit cell is proposed. Firstly, the nominal Poisson’s ration and Young’s modulus in the longitudinal and circumferential directions are derived analytically. The effect of the geometry parameters of the DVMS tube on the mechanical properties is studied thoroughly. Also, the effect of the width in the radial direction on these mechanical properties is analyzed. Secondly, the finite element (FE) method is utilized to obtain the numerical solutions and verify the accuracy of the analytical solutions. The results show that there is a good agreement between the results obtained by the two methods when the width is smaller enough.

Experimental factors have great influence on the vibration medal test. Using a box body of automobile gearbox, firstly, the first several orders frequencies can be calculated by using finite element analysis method. Secondly, based on the vibration modal tests of box body of automobile gearbox, the corresponding modal parameters can be obtained on the both elastic suspension and elastic support; then the effect of the experimental results were discussed on different constraint conditions. Thirdly, by comparing the results of finite element analysis method with the experiment results on different constraint conditions, the reasons of the influence which caused by the constraint conditions were discussed. Finally, suggestion for reducing the errors induced by constraint conditions was put forward in the article. The results of the experimental Analysis have engineering significance.

Statistical energy analysis (SEA) has become an accepted method to predict noise, vibration and harshness (NVH) in vehicles. There may be, however, significant differences between the absolute value of the predicted mean and the value observed from measurement. These differences are associated with the statistical variability of the prediction. The methods for the statistical response prediction have been summarized in this paper. A mode decomposition method, which can simplify the response prediction in SEA when there are so many input resources act on the vehicle, was presented, and some ways needed to improve the precision of the statistical response prediction have been point out.

With the aim of improving vehicle steering stability through the introduction of active steering control in obstacle avoidance, the author undertook the development of the fuzzy neural networks. By using back propagation neural network as the base, it can use fuzzy theory and neural networks together to form a fuzzy neural networks control system. So it can auto pick-up the fuzzy rule and build the subordinate function. The result of simulation analyses and experiments indicate that the method proposed in the paper can achieve safe and stability in steering control of obstacle avoidance of intelligent mobile vehicle.

In order to improve the isolating performance of the power-train mount system of one light truck with the uncontrollable parameters of the stiffness and location, a robust optimization design problem based on the 6-DOF dynamical equation of the power-train mount system is presented in the paper. For the robust optimization design of the power-train mount system with the uncontrollable parameter variations, a deterministic, non-gradient approach for objective robust and constraint robust optimization is discussed based on the design of orthogonal experiment and Genetic Algorithm.