含层间界面损伤复合材料层压结构半解析法研究

发布时间：2018-02-25 22:30

本文关键词： 复合材料压电材料弱粘接分层有限元法无网格法半解析法　出处：《上海交通大学》2015年博士论文　论文类型：学位论文

【摘要】：复合材料层压结构层间界面损伤依据损伤程度的强弱可以分为两种形式,层间界面弱粘接损伤和分层损伤。层间界面弱粘接损伤的特点是层间应力连续而层间位移不连续,分层损伤的特点是层间应力和层间位移均不连续,即接触面可以自由地相对张开和滑动。在服役状态下,结构会承受各种载荷,将导致层间界面损伤的扩展。复合材料结构的刚度和强度会随之显著下降,并引发严重的安全隐患。因此,含层间界面损伤复合材料层压结构的力学性能研究具有重要意义。针对含层间界面损伤复合材料层压结构的弯曲、振动、屈曲、热屈曲特性和剩余强度的研究,本文提出了两种方法:基于两类变量变分原理的Hamilton正则方程有限元与径向基点插值无网格耦合半解析法和基于局部加权残值法的Hamilton正则方程局部径向基点插值无网格半解析法。在这两种方法中沿厚度方向采用解析法,保证了层间位移和平面外应力的连续性,数值结果精度高,平面内采用数值方法,能处理复杂的侧面边界条件及复杂的外载荷等问题,通过传递矩阵技术的实施,使得控制方程只含有结构上下表面的位移变量和应力变量,显著地减少了控制方程的未知量,计算效率高,对应力和位移两类变量没作其他任何假设,正交异性甚至各向异性材料的剪切效应得到了充分体现。另外,针对复合材料层压结构屈曲和热屈曲问题,本文修正了其中的能量密度函数,并扩展应用到含层间界面损伤压电材料层压结构的力学性能分析上。本文用含两种损伤形式的复合材料和压电材料层压结构的弯曲、振动、屈曲、热屈曲特性和含分层损伤复合材料层压结构分层前缘能量释放率相关算例验证了所提方法的准确性和有效性。
[Abstract]:The interlaminar interface damage of composite laminated structure can be divided into two forms according to the degree of damage, namely, the interlaminar interface weak adhesion damage and delamination damage. The characteristics of the interlaminar interface weak bonding damage are that the interlaminar stress is continuous and the interlaminar displacement is discontinuous. Delamination damage is characterized by the discontinuity of interlayer stresses and displacements, that is, the free opening and sliding of contact surfaces. The stiffness and strength of composite structures will decrease significantly, which will lead to serious safety risks. It is of great significance to study the mechanical properties of composite laminated structures with interlaminar interface damage. The bending, vibration, buckling, thermal buckling and residual strength of composite laminated structures with interlaminar interface damage are studied. In this paper, two methods are proposed: finite element method for Hamilton canonical equation and coupled meshless semi-analytical method for radial base point interpolation based on variational principle of two classes of variables and local radial base point interpolation for Hamilton canonical equation based on locally weighted residual method. In these two methods, the analytical method is used in the direction of thickness. The continuity of interlayer displacement and out-of-plane stress is ensured, the accuracy of numerical results is high, the numerical method is adopted in the plane, and the complex side boundary conditions and complex external loads can be dealt with. The governing equation contains only the displacement variables and stress variables of the upper and lower surfaces of the structure, which significantly reduces the unknown amount of the governing equation, and has a high computational efficiency. The corresponding forces and displacements are not assumed in any other way. The shear effect of orthotropic and even anisotropic materials is fully reflected. In addition, the energy density function is modified for the buckling and thermal buckling of composite laminated structures. In this paper, the bending, vibration and buckling of composite and piezoelectric laminated structures with interlaminar interface damage are investigated. Examples of thermal buckling characteristics and energy release rate of laminated composite structures with delamination damage verify the accuracy and effectiveness of the proposed method.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB33

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