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A novel protective structure, based on shrimp chela structure and the shape of odontodactylus scyllarus, has been shown to improve impact resistance and energy absorption. A finite element model of NiTi alloy with shape memory was constructed based on the basic principles of structural bionics. The protective structure utilizes NiTi alloy as the matrix, a material with many advantages including excellent compression energy absorption, reusability after unloading, and long life. The mechanical properties of the single-layer model were obtained by static crushing experiments and numerical simulations. Building upon the idea of the monolayer bionic structure design, a two-layer structure is also conceived. Both single-layer and double-layer structures have excellent compression energy absorption and self-recovery capabilities. Compared with the single-layer structure, the double-layer structure showed larger compression deformation and exhibited better energy absorption capacity. These results have important academic and practical significance for improving the impact resistance of protective armor. Our study makes it possible to repair automatic rebounds under the action of pressure load and improves the endurance and material utilization rate of other protective structures.

Real-time simulation of grassland, especially the dynamic grassland under the effect of external forces such as wind is an important research topic in photorealistic simulation of natural scenes. It is also a challenging problem due to the huge number of grass blades. In this paper we put forward a method to represent the large area of dynamic grass realistically in real-time. In the method, we implement the real-time grass representation by using shell strategy, and based on the strategy, we further realize the simulation of dynamic grassland in wind. In order to solve the over transparent problem in the silhouette area of layered textures representation, we use vertical slices strategy, with which the rendering effects are improved. The grass shift in wind is simulated by moving the multilayer vertices. The vertices movement is computed by vertex shader program in GPU to achieve high simulating speed. To improve the rendering effects, we utilize the fragment shader of GPU to compute the grass lighting model. The quadrilateral continuity issues is also considered in the generation of layered grass textures. Experimental results show that our method can simulate dynamic grassland realistically in real-time, making our method is valuable for the application in virtual reality and games.

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This paper concentrates on modeling and simulation of the automatic transmission assembly using Matlab/Simulink. The entire simulink model includes four major models. They are the torque convertor and its lockup clutch model, the automatic transmission gearbox model, the equivalent spring model and the logical model respectively. After building the model, a comparison between this Simulink model and Carsim software is provided and the result curves matches very well, which proves that the Simulink model is accurate.