Process Modeling of Composite Materials: Residual Stress Development during Cure. Part II. Experimental Validation
Process Modeling of Composite Materials: Residual Stress Development during Cure. Part II. Experimental Validation
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DOI：
10.1177/002199839202601605
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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：
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作者：
Scott R. White;H. T. Hahn
在一篇配套论文[1]中，开发了一种工艺模型，用于研究热固性聚合物基复合材料在热压或热压过程中的残余应力发展。几个材料性能表征研究需要作为输入到这个模型。本文总结了输入模型所需的特征化研究的结果，并通过测量加工引起的剩余曲率的非对称正交铺层层压板的间歇固化来完成模型的验证。选用IM 6/3100石墨/双马来酰亚胺复合材料体系进行研究。纵向和横向的机械性能被证明是增加在固化周期期间，由于基体强度和刚度的增加和纤维/基体粘结的发展。热应变被证明在固化过程中保持相对恒定。化学应变发生在固化周期的早期，并在固化完全发展之前完成。BMI的粘弹力学响应强烈依赖于固化状态。在低固化状态下，蠕变响应相当显著。当接近完全固化时，材料变得主要是弹性的。基于实测的输入数据，粘弹性分析表明，对于典型的固化循环，化学应变对残余应力的贡献小于4%。一个很好的相关性模型预测和实验翘曲数据之间的固化周期的调查。
In a companion paper [1] a process model was developed for investigation of residual stress development during autoclave or hot press processing of thermosetting polymer matrix composites. Several material property characterization studies are re quired as input to this model. The present paper summarizes the results of the character ization studies required for input to the model and validation of the model is accomplished by the intermittent cure of unsymmetric cross-ply laminates in which the processing- induced residual curvatures are measured. An IM6/3100 graphite/bismaleimide composite system was chosen for the study. Longi tudinal and transverse mechanical properties were shown to increase during the cure cycle due to increase in matrix strength and stiffness and development of the fiber/matrix bond. Thermal strains were shown to remain relatively constant during cure. Chemical strains occur early in the cure cycle and are completed before cure is fully developed. The vis coelastic mechanical response of BMI is strongly dependent on the cure state. At low cure states the creep response is quite significant. As full cure is approached, the material becomes predominantly elastic. Based on the measured input data, the viscoelastic analy sis showed that the contribution of chemical strains to residual stress was less than 4% for a typical cure cycle. A good correlation was obtained between model predictions and ex perimental warpage data for the cure cycle investigated.