改进的虚裂纹闭合技术及其在复合材料脱层分析中的应用

提出一种改进的虚裂纹闭合技术（ＶＣＣＴ）对轮胎带束（一咱复合材料结构）不同脱层长度下的应变能释放率进行了计算。将强度裂纹闭合的位移作了一种可变约束施加在变形后的裂纹尖端，约束反力作了裂纹尖端力计算，应变能释放率由裂纹尖端力和约束位移的乘积得到。该方法的优点是简便易行，在物理理解上直观，实施起来方便。本文就用该技术对带束脱层进行了断裂力学分析，给出数值结果，并对带束的脱层寿命进行了评价。

A new VCCT and its application in composite delamination analysis

In this paper, a modified VCCT (Virtual Crack Close Technology) is developed to compute strain energy release rates of tire belt(a kind of composite structure) under different delamination lengths. The crack tip close displacements are enforced on the deformed configuration as the increment constraints, crack tip force being constraint reaction force, strain energy release rates being equal to the sum of constraint displacement timing constraint force. The advantages of this method are simple, convenient, physical direct, and saving computing amount. In addition, as an example, the belt delamination analysis is made using this method, and the numerical results are given. Then the evaluation of tire belt life is presented.