Process Modeling of Composite Materials: Residual Stress Development during Cure. Part I. Model Formulation
Process Modeling of Composite Materials: Residual Stress Development during Cure. Part I. Model Formulation
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DOI：
10.1177/002199839202601604
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发表时间：
1992-01
影响因子：
2.9
通讯作者：
Scott R. White;H. T. Hahn
中科院分区：
文献类型：
--
作者：
Scott R. White;H. T. Hahn
在复合材料部件的生产中，相关的工艺参数是时间、温度和压力。这三个参数的明智选择生产出完全固化、压实和高质量的复合材料。与推荐的加工条件稍有偏差就会导致质量不合格。复合材料加工中最重要的问题之一是残余应力。加工引起的残余应力可能足够高，甚至在机械加载之前在基体内引起开裂。基质的这种微裂纹会使纤维暴露于化学侵蚀的降解。由于引入了预加载，残余应力会对强度产生不利影响。本文所考虑和讨论的主题已被选择来处理的问题，了解如何在加工过程中的残余应力的发展，以及如何可以预测。本文提出了一个可用于预测复合材料层合板固化过程中残余应力历史的过程模型。该模型包括化学和热应变的影响，并假设材料表现出线性维斯粘弹性行为。一个唯象模型被用来预测在固化周期的固化历史的程度。允许基于对固化状态（固化程度）的功能依赖性来开发机械性能，并且将横向顺应性作为唯一的时间依赖性顺应性。同时应用固化动力学和粘弹性应力分析，得到了非对称正交铺层层板的残余弯矩和曲率。实验相关性在随附的论文中提供。
In the production of composite parts the pertinent processing parameters are time, temperature, and pressure. A judicious choice of these three parameters pro duces composites which are fully cured, compacted, and of high quality. Slight deviations from the recommended processing conditions can result in unacceptable quality. One of the most significant problems in the processing of composites is residual stresses. Processing-induced residual stresses can be high enough to cause cracking within the matrix even before mechanical loading. This microcracking of the matrix can expose the fibers to degradation by chemical attack. Strength is adversely affected by residual stresses since a pre-loading has been introduced. The topics considered and discussion presented in this paper have been chosen to ad dress the issue of understanding how residual stresses develop during processing and how they can be predicted. A process model has been developed which can be used to predict the residual stress history during the curing of composite laminates. This model includes the effects of chemical and thermal strains and assumes the material to exhibit linear, vis coelastic behavior. A phenomenological model is used to predict the degree of cure history during the cure cycle. Mechanical properties are allowed to develop based on a functional dependence on the cure state (degree of cure) and the transverse compliance is taken as the only time-dependent compliance. Simultaneous application of the cure kinetics and a vis coelastic stress analysis yields the residual moments and curvatures for unsymmetric cross-ply laminates. An experimental correlation is provided in an accompanying paper.