环氧树脂基体中圆柱夹杂引起的界面残余应力研究

Investigation of Interfacial Residual Stress Caused by Cylindrical Inclusions in Epoxy Resin Matrix

环氧树脂基复合材料中的填充物会引起界面残余应力,这将影响复合材料的力学性能与使用寿命。将不同弹性模量或不同直径的圆柱金属丝作为环氧树脂基体中的填充物以制备试样。在显微光弹测试系统中获取平面偏振光场中试样的光弹条纹图,同时利用Berek补偿器进行补偿获得非整级次等差线条纹级次,并结合试样界面处环向残余应力值等于径向残余应力值的弹性力学解对圆形界面处的残余应力进行测试。实验结果表明,相同直径条件下,随着圆柱夹杂弹性模量的增大,圆柱体抵抗环氧树脂基体收缩变形的能力增强,复合材料界面残余应力增大;而随着圆柱夹杂直径的减小,界面残余应力也增大,同时发现夹杂圆柱体的弹性模量对复合材料界面残余应力的影响比夹杂圆柱体的尺寸对界面残余应力的影响更大。

Fillers in epoxy-based composites can cause interfacial residual stress,which affects the mechanical properties and service life of the material.Cylindrical wires with different elastic modulus or diameters were placed as fillers in epoxy resin matrix to prepare samples.The photoelastic fringe pattern of the samples in plane polarized light field was obtained in the microscopic photoelastic measurement system.Meanwhile,the non-integral order isometric fringe order was obtained by using Berek compensator.The residual stress at the circular interface of the specimen was measured by combining the non-integral order isometric fringe order with the elastic mechanical solution(i.e.the annular residual stress is equal to the radial residual stress)at the interface.The experimental results show that with the increase of elastic modulus of cylindrical inclusion,the cylindrical resistance to shrinkage deformation of epoxy resin matrix increase,and the residual stress of composite interface increase.With the decrease of cylindrical inclusion diameter,the interface residual stress also increase.It was found that the elastic modulus of the inclusion cylinder had more influence on the interface residual stress than the size of the cylinder inclusion.