为了解决含有橡胶材料的界面断裂问题,提出了一种改进的虚裂纹闭合技术,该技术采用逐步线性化的方法,同时考虑了材料非线性与几何非线性的影响。首先,计算了双裂纹橡胶试件裂纹尖端的能量释放率,通过与已有文献的比较,可知所提出的改进的虚裂纹闭合技术是可靠、有效的。其次,对含有橡胶夹层的SLB模型进行了研究,通过计算分层前缘能量释放率Ⅰ型、Ⅱ型分量,和其与总能量释放率的比值,可知橡胶材料的引入使结构的能量释放率总量增大,Ⅱ型分量的比例明显增大。在多材料体系连接结构的断裂分析中,计算了不同分层位置下裂纹的能量释放率,并考虑了外层纤维缠绕层尺寸变化对能量释放率的影响。最后,提出了相应的多材料体系构件的断裂准则。
In order to deal with the issue of interface fracture including rubber material,a modified virtual crack closure technique was proposed,in which both material and geometric nonlinearities were considered through the method of step-by-step linearization.Firstly,the energy release rate was calculated on the crack tip of rubber specimens with double cracks.It can be seen through the comparison with existing papers that the modified virtual crack closure technique provided is of validity and efficiency.Then,an SLB model with a rubber sandwich was studied,the calculation of mode Ⅰ and Ⅱ component of energy release rate indicates that the introduction of a rubber sandwich raises the total energy release rate and greatly increases the proportion of mode Ⅱ component.In the fractural analysis of joint-structures with multi-material system,energy release rates under different positions of delaminations were calculated,and the effect of dimension of outer fiber-reinforced composite upon the value of total energy release rate was considered.Finally,a fracture criterion for joint-structures with multi-material system was established.