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为计算复合材料厚板在三维应力状态下的极限承载,综合考虑复合材料厚板的三维应力特性和厚板的本构理论,基于非线性本构关系与增量步迭代法,以Hashin 3D失效准则为单层板失效判据;当层压板中有一层或多层被检测到失效时,对失效层进行刚度折减,并在增量过程中不断更新刚度矩阵。同时,对航空结构件中使用的复合材料厚层压板进行了双轴载荷下的渐进失效过程模拟,分别计算了两种碳纤维环氧复合材料单向带在两种铺层形式以及三种载荷工况下的初始失效和极限承载包线;并给出了不同的铺层和材料组合下层压板的初始失效与最终失效强度包线及每一段所代表的失效模式,展示了层压板的渐进失效过程。本文研究方法解决了对复合材料厚层压板失效过程状态的跟踪与判定问题,同时又不必去建立复杂的三维有限元模型,减小了计算量。
In order to calculate the ultimate bearing capacity of composite slab in three-dimensional stress state, considering the three-dimensional stress characteristics of composite slab and the constitutive theory of slab, based on the nonlinear constitutive relationship and increment step iteration method, The criterion is the single-plate failure criterion. When one or more layers in the laminate are detected as failure, the stiffness of the failure layer is reduced and the stiffness matrix is continuously updated during the increment. At the same time, the progressive failure process under the biaxial load of composite thick laminates used in aeronautical structures was simulated. Two types of carbon fiber epoxy composite unidirectional strips were calculated respectively in two types of lamination and three kinds of load The initial failure and the ultimate load envelope are given. The initial failure and final failure strength of the laminate under different plies and combinations of materials are given, and the failure modes represented by each of the sections are presented, showing the progressive failure process of the laminate . The research method of this paper solves the problem of tracking and judging the failure state of composite thick laminates without having to build a complex three-dimensional finite element model and reduce the computational cost.