Creep Fracture of Graphite/Polymer Composites: Experiments and Modeling to Predict Lifetime

CMS 9800128 PI：L.S. Schadler RPI 摘要 对单向石墨纤维/聚合物基复合材料在拉伸下的蠕变断裂进行了实验和理论相结合的研究。蠕变断裂在各种应用中都很重要，例如纤维缠绕压力容器、拉挤杆和梁、海上平台稳定电缆和管道，所有这些都需要长时间承受高负载。 该模型结合了复合材料中的微观机械和统计失效过程，并产生强度和长期寿命的概率分布。显微拉曼光谱 (MRS) 用于研究接近纤维直径的长度尺度下的基体蠕变以及随时间变化的界面脱粘和滑移现象。 开发了复合材料的快速计算微力学模型，为大型随机纤维断裂阵列和断裂簇提供应力和位移场，用于大型蒙特卡罗模拟。 MRS 实验和计算模型交互地用于解释随时间变化的实验应力分布。 ***

CMS 9800128 PI: L.S. Schadler RPI ABSTRACT A combined experimental and theoretical study of the creep fracture in unidirectional, graphite fiber/polymer-matrix composite materials in tension is conducted. Creep fracture is important in various applications such as filament wound pressure vessels, pultruded rods and beams, offshore platform stabilizing cables and pipes, all of which sustain high loads for long times. The model incorporates micromechanical and statistical failure processes in the composite, and yields probability distributions for strength and long-term lifetime. Micro-Raman Spectroscopy (MRS) is used to study matrix creep and time-dependent interfacial debond and slip phenomena at length scales closer to fiber diameter. Fast comutational micromechanics model for the composite is developed that provides stress and displacement fields for large random arrays of fiber breaks and break clusters for use in large Monte Carlo simulations. The MRS experiments and computational model are interactively used to interpret experimental stress profiles as they change over time. ***