复合材料层板冰雹高速冲击损伤预测及失效分析

针对冰雹冲击对复合材料结构安全造成的潜在风险，提出了一种基于连续介质损伤力学的非线性有限元模型，研究了碳纤维复合材料层板冰雹高速冲击力学行为。综合采用拉格朗日法和光滑粒子流体动力学（SPH）法对冰雹进行建模，引入水的状态方程描述冰雹破碎后的流动特性；考虑应变率的单向复合材料本构模型，根据三维Hashin失效准则及材料刚度折减方案，进行复合材料层内损伤预测；引入界面单元结合双线性内聚力模型模拟层间分层现象；编写用户材料VUMAT子程序，实现基于ABAQUS/Explicit显式模块的数值求解。模拟了冰雹高速冲击复合材料层板的瞬态过程，分析了材料的损伤特性和失效机理。探讨了冰雹冲击速度、冲击角度对层板冲击损伤性能的影响，为复合材料结构冰雹冲击问题数值分析提供参考。 

Damage prediction and faiure mechanism of composite aminates under high-veocity haistone impact

Aiming at the potential risk of hailstone impact on the safety of composite structures, a continuum damage mechanics based nonlinear finite element model was developed to study the mechanical behavior of carbon fiber composite laminates under high-velocity hailstone impact. The Lagrangian method and smoothed particle hydrodynamics (SPH) method were used together to model the impact of hailstone, and the equation of state of water was introduced to describe the flow characteristics of the hailstone after breaking. A rate-dependent constitutive model of unidirectional composite, as well as 3D Hashin failure criteria and material stiffness reduction rule, was applied to predict the in-plane damage in composite layers. Interface elements governed by bilinear cohesive model were employed to simulate the inter-laminar delamination phenomena induced by impact. A user material subroutine VUMAT was coded and implemented to obtain the numerical solution based on ABAQUS/Explicit solver. The transient process of composite laminates under hailstone impact was reproduced and the damage characteristics and failure mechanism were analyzed in detail. The effects of impact velocity and impact angle of hailstone on the impact properties of composite laminates are discussed, which provides proper reference for numerical investigation of hailstone impact problems in composite structures.