Basic study of the strength evaluation of honeycomb structure which has an adhesion defect

本文将断裂力学中裂纹问题的方法应用于具有粘结缺陷的蜂窝结构的强度评定。对粘接缺陷尖端附近的应力分布进行了详细的分析。得出如下结论。(1)从基于有限元法的数值分析结果可以清楚地看出，应力奇异性发生在附近的粘附缺陷的尖端。(2)根据理论分析模型，明确了粘着缺陷尖端应力奇异性的阶数为-1/2。(3)通过理论分析模型，得到了蜂窝胶粘缺陷尖端形成奇异应力场的一般形式。(4)在此基础上，引入了表征奇异应力场强度的参数应力强度因子。(5)应力强度因子与粘附缺陷的长度的平方根成比例，这是检查施加它的每个几何形状的形状对 * 幂膨胀系数的影响的结果。（6）应力强度因子被控制在粘附层上的剪切应力中，并且与剪切应力的值成比例。

In the present study, the approach of the fracture mechanics for the crack problem is applied to the strength evaluation of honeycomb structure, which has an adhesion defect. A detailed examination was done about stress distribution in the neighborhood at the tip of the adhesion defect. It got the following conclusion.(1) It was cleared from results of the numerical analytic result based on the finite element method that the stress singularity occurs in the neighborhood at the tip of the adhesion defect.(2) Based on the theory analytic model, it was cleared that the order of the stress singularity at the tip of the adhesion defect is -1/2.(3) The general style of singular stress field to be formed at the tip of the adhesion defect of honeycomb was found by the theory analytic model.(4) Parameter of stress intensity factor, which defines the strength of the singular stress field, is introduced based on the above investigation.(5) The stress intensity factor is in proportion to the square root of the length of the adhesion defect as a result of examining the influence of the form like each geometry which exerted it on * power expansion coefficient(6) The stress intensity factor is controlled in the shear stress on the adhesion layer, and is in proportion to the value of the shear stress.