考虑应变依赖性的硬涂层复合结构有限元分析

在简要介绍硬涂层材料应变依赖性的基础上,推导了用迭代有限元法求解硬涂层复合结构动力学特性的原理,进一步提出了求解硬涂层复合结构固有频率和振动响应的计算流程,即由振动响应值来修正硬涂层材料参数,进而迭代求解硬涂层复合结构的动力学参数.最后以一个涂敷MgO+Al2O3硬涂层的悬臂梁为例进行了实例研究,在考虑MgO+Al2O3硬涂层材料应变依赖性的基础上,获得了不同激励幅度下悬臂梁的固有频率和振动响应,并与线性计算结果进行了比对.结果表明;该硬涂层复合结构悬臂梁具有软式非线性,同时,对应于不同的激励幅度,迭代计算获得的共振响应相对于线性计算值减少了29%~48%,说明硬涂层材料的应变依赖性会进一步增强硬涂层的减振效果.

Finite element analysis of hard-coating composite structure considering strain-dependent characteristic

On the basis of introducing the strain-dependent characteristic of hard-coating material, the dynamic characteristic solution theory of iterative finite element method was derived. Moreover, the processes of calculating natural frequency and vibration response were presented, which can be summarized as: the hard coating material parameters were corrected by the vibration response, and then the dynamic parameters were solved by the iterative solution program. At last, a cantilever beam coated with MgO+Al₂O₃ hard coating was chosen to display the effectiveness of the proposed method. Considering the strain-dependent characteristic of MgO+Al₂O₃ hard coating, the natural frequency and vibration response were obtained under different exciting levels and also compared with the relative values obtained by linear calculation. Results show that the hard-coating composite structure cantilever beam displays the soft nonlinear phenomenon, and the resonance responses reduce by 29%-48% compared with linear calculation correspondingly to different exciting levels. This shows that the strain-dependent characteristic of hard-coating material can promote the effect of vibration reduction.