Nondestructive Evaluation of Debonding in Fibrous Composites through Multiaxial Loading

提出了一种新的纤维复合材料脱粘无损评价方法的可行性。该方法基于细观力学预测，结果表明，单向金属基复合材料的脱粘损伤对纤维方向的轴向弹性模量值没有影响，但对承受复合应力状态的纯纵向复合材料的剪切弹性模量值有显著影响，这仍是一个悬而未决的问题。建议的测试方法将利用微观力学预测的知识，通过一系列精心选择的顺序、多轴加载增量来评估碳化硅/钛管材的脱粘。这种方法是非破坏性的，因为原位应力和应变测量提供了必要的数据。不需要将样品从试验机中取出、获取边缘复制品、使用x射线设备或对样品的切片部分进行显微镜研究。

It is proposed to determine the feasibility of a new method for nondestructive evaluation of debonding in fibrous composite materials. The method is based upon micromechanical predictions which indicate that damage in the form of debonding in unidirectional metal matrix composites has no influence on the axial modulus in the fiber direction, but it does have an appreciable influence on the shear modulus for loading by pure longitudinal composites subjected to combined stress states remains an open question. The proposed test method will exploit the knowledge available from the micromechanical predictions to assess debonding in silicon-carbide/titanium tubes through a series of carefully chosen sequential, multiaxial load increments. The method is nondestructive in the sense that in - situ stress and strain measurements provide the necessary data. It is not necessary to remove the specimen form the test machine, take edge replicas, use x-ray equipment, or conduct microscopic studies on sectioned portions of the specimens.