基于剪切非线性三维损伤本构模型的复合材料层合板失效强度预测

Failure strength prediction of composite laminates using 3D damage constitutive model with nonlinear shear effects

  • 摘要: 基于连续损伤力学,建立了同时考虑复合材料剪切非线性效应和损伤累积导致材料属性退化的三维损伤本构模型。模型能够区分纤维损伤、基体损伤和分层损伤不同的失效模式,并定义了相应损伤模式的损伤变量。复合材料层合板层内纤维初始损伤采用最大应力准则判定,基体初始损伤采用三维Puck准则中的基体失效准则判定,分层初始损伤采用三维Hou准则中的分层破坏准则判定,为了计算Puck失效理论中的基体失效断裂面角度,本文提出了分区抛物线法,通过Matlab软件编写计算程序并进行分析。结果表明,与Puck遍历法和分区黄金分割法对比,本文提出的分区抛物线法有效地降低了求解断裂面角度的计算次数,提高了计算效率和计算精度。推导了本构模型的应变驱动显式积分算法以更新应力和解答相关的状态变量,开发了包含数值积分算法的用户自定义子程序VUMAT,并嵌于有限元程序Abaqus v6.14中。通过对力学行为展现显著非线性效应的AS4碳纤维/3501-6环氧树脂复合材料层合板进行渐进失效分析,验证了本文提出的材料本构模型的有效性。结果显示,已提出的模型能够较准确地预测此类复合材料层合板的力学行为及其失效强度,为复合材料构件及其结构设计提供一种有效的分析方法。

     

    Abstract: Based on the continuum damage mechanics, a 3D damage constitutive model which takes into account the nonlinear shear behavior of composites and material properties degradation due to damage development was proposed. The model differentiates between different failure modes, such as fiber failure mode, matrix failure mode and delamination. The damage variables corresponding to each failure mode were defined. The onsets of fiber damage, matrix damage and delamination of composite laminates were predicted using maximum stress failure criteria, Puck’s matrix failure criteria and Hou’s delamination criteria, respectively. In order to predict the angle of fracture surface in Puck’s matrix fracture failure theory, a selective parabola algorithm was proposed and coded using Matlab procedure. Compared with the Puck’s algorithm and the selective range golden section search algorithm, it shows that the selective parabola algorithm effectively reduces the number of calculations and improves the calculation efficiency and accuracy. A strain-driven explicit integration algorithm for the proposed material constitutive model was developed to update stresses and solution dependent state variables. The user-defined material subroutine VUMAT containing the numerical integration algorithm was coded and implemented in the finite element procedure Abaqus v6.14. The efficiency of the material constitutive model was demonstrated through progressive failure analyses of AS4 carbon fiber/3501-6 epoxy composite laminates, the mechanical behavior of which demonstrates significant nonlinear shear effects. The numerical results show that the proposed model is able to predict the mechanical behavior and failure strength of composites with sufficient accuracy. The proposed approach provides an efficient method for the design of composite components and structures.

     

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