C_SiC陶瓷基复合材料界面力学性能的离散元模拟.docVIP

  C/SiC 陶瓷基复合材料界面力学性能的离散 元模拟# 李林涛，谭援强，姜胜强** 5 10 （湘潭大学机械工程学院，湘潭 411105） 摘要：复合材料结构非常复杂，界面特性是决定复合材料性能的关键性因素。本文用离散元 法(DEM)，用 BPM(parallel bond model)分别建立并校准了 SiC 陶瓷基体和碳纤维的离散元模 型，采用位移软化接触模型表征层间和纤维/基体之间的界面元损伤双线性本构关系。通过 DCB 试验和微滴脱黏试验分别对其界面强度进行校准，动态的观察了裂纹的扩展、界面处 塑性变形和界面的脱黏过程。结果表明位移接触软化模型可以很好的表征界面损伤过程，采 用离散元法可以很好的动态模拟较复杂复合材料的损坏过程。 关键词：C/SiC 复合材料；界面性能；离散元法(DEM)；位移软化接触模型；模拟 中图分类号：TB332 15 Study on interfaces properties of C/SiC ceramic matrix composites using discrete element method LI Lintao, TAN Yuanqiang, JIANG Shengqiang (School of Mechanical Engineering, Xiangtan University, Xiangtan 411105) 20 25 30 Abstract: Structure of composites was very complicated, Interface properties was the key factor in composite material properties. By using BPM(parallel bond model), mechanical properties of SiC ceramics matrix and carbon fiber were simulated through setting up and calibrating Discrete Element Models (DEM). The displacement-softening contact model was used in interlayer and the same in interface between matrix and fiber to characterize the interface element damage bilinear constitutive relation. Which were calibrated by DCB test (Double Cantilever Beam virtual test) and microbond test respectively. Plastic deformation and the cracking growth situation were observed in these simulation tests, and the dynamic processes of interface debonding. The results show that the displacement-softening contact model could characterize interfacial damage process well and it is good to simulate dynamic damage process for more complex composite materials using discrete element method. Key words: C/SiC composites; interfacial properties; discrete element method; displacement-softening contact model; simulation 0 引言  35 40 C/SiC 陶瓷基复合材料具有耐高温、抗腐蚀、高强度、高韧性等优良的高温力学性能, 在航空、航天、航海、汽车等领域有着广泛应用[1]。与 SiC 陶瓷材料相比，由于碳纤维的 加入，C/SiC 陶瓷基复合材料有效的提高了韧性，使陶瓷脆性材料表现出伪塑性行为，减少 了发生灾难性损坏的几率[2, 3]。 目前而言，国内外研究学者主要采用有限元法（FEM）对复合材料进行计算模拟研究。 张博明等[4]通过有限元模拟方法分析微观参数（如，界面强度等）对材料宏观性能的影响， 从而对复合材料进行优化设计。李典森等[5]用有限元建立编