陶瓷纤维梯度增强活塞的梯度方程研究

Study on Material Composition Functions of Gradient Aluminum Matrix Composite Piston Reinforced by Ceramic Fibers

功能梯度材料零件具有单质材料零件无法比拟的理化性能优势,然而由于材料分布复杂以及对功能梯度材料本身性能研究不充分,使性能分析存在很多困难。论文应用复合材料热性能理论,采用有限元分析软件ADINA,分析陶瓷纤维梯度增强活塞(材料梯度方程的参数不同)的温度分布和应力分布,结果表明陶瓷纤维梯度层可以明显改变活塞温度分布,缓和由于热膨胀系数不匹配,在陶瓷纤维增强层与活塞本体交界处产生的应力。根据计算结果拟合出温度峰值、整体应力峰值和层间应力峰值与方程系数之间的曲线,并加以验证。

Functionally gradient material components have better physical and chemical properties than homogeneous material components. Because of material distributing complexity and insufficient study on functionally gradient material ,there are lots of difficulties in analysis of functionally gradient material components. Theory of thermal properties of composites and finite element analysis software ADINA are used to analyze the temperature field and stress field of gradient aluminum matrix composite piston reinforced by ceramic fibers which have different material composition functions. The result indicates that using gradient aluminum matrix composite layer reinforced by ceramic fibers can remarkably change the temperature distribution over the piston and relax the stresses at the interface between the gradient aluminum matrix composite layer reinforced by ceramic fibers and the noumenon of piston which is caused by mismatch among different thermal expansion coefficients. Based on the computing results, the curves of thermal peak value vs gradient function coefficient, entire stress peak value vs gradient function coefficient,and stress peak value between layers vs gradient function coefficient can he fitted and proved by computing other pistons.