厚截面复合材料层间剪切性能的尺寸效应  

Effect of pore microstructure on interlaminar shear properties of thick section composites

作　　者：王晓宇 王雅娜 郝自清 谌广昌[3] 魏高健 刘刘 WANG Xiaoyu;WANG Yana;HAO Ziqing;CHEN Guangchang;WEI Gaojian;LIU Liu(School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China;Testing Research Center for Aeronautical Materials,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Science and Technology Development Department,China Helicopter Design and Research Institute,Tianjin 333001,China)

机构地区：[1]北京理工大学宇航学院,北京100081 [2]中国航发北京航空材料研究院检测研究中心,北京100095 [3]中国直升机设计研究所科技发展部,天津333001

出　　处：《航空材料学报》2024年第6期61-71,共11页Journal of Aeronautical Materials

基　　金：国家自然科学基金(11472043);基础加强计划重点基础研究项目(2019-JCJQ-ZD-308-00)。

摘　　要：针对厚截面玻璃纤维增强树脂基复合材料,开展数字图像相关技术辅助的短梁剪切实验,获得不同厚度单向复合材料层间剪切行为随厚度的变化规律。为了探索材料层间剪切力学行为的尺寸效应机制,通过试样切片扫描电镜照片,观察不同厚度试样的孔隙微观特征。采用图像处理,获得不规则孔隙轮廓,提出定量表征微观特征的参数。随机生成包含纤维、基体、纤维/基体界面和孔隙的三维代表体元(RVE)模型,并通过数值分析研究不同尺寸和分布的不规则孔隙对复合材料层间剪切强度的影响。短梁剪切实验结果表明单向复合材料的层间剪切力学行为与试样厚度无关,但剪切强度随着试样厚度的增加下降。图像分析结果可见不同厚度试样孔隙的分布规律,大小,集中和不规则程度存在显著差异。RVE的数值分析结果表明:损伤是由于靠近孔隙的纤维与基体界面破坏引起的,且随着在相同孔隙率的情况下最大孔隙尺寸的增加,厚截面复合材料的层间剪切强度下降。同时孔隙集中度、孔隙率也对材料层间剪切强度有明显的影响。上述实验与分析结果表明厚截面复合材料层间剪切强度尺寸效应与材料孔隙的微观特征参数有关,随复合材料厚度增加,孔隙率、最大孔隙尺寸和集中程度变大,剪切强度下降,因此不同厚度材料孔隙微观特征的差异性是导致了材料层间剪切强度下降的重要机制之一。Short beam shear tests conbined with digital image correlation were carried out for thick-section glass fiber reinforced resin matrix composites,and the variation of interlaminar shear behavior of unidirectional composites with different thicknesses with thickness was obtained.In order to explore the size effect mechanism of interlaminar shear mechanical behavior of materials,the microscopic characteristics of pores of samples with different thicknesses were observed through scanning electron microscope photos of sample slices.Image processing was used to obtain the contours of irregular pores,and parameters for quantitative characterization of microscopic characteristics were proposed.A three-dimensional representative volume element(RVE)model containing fibers,matrix,fiber/matrix interface and pores was randomly generated,and the effect of irregular pores of different sizes and distributions on the interlaminar shear strength of composites was studied by numerical analysis.The results of short beam shear tests showed that the interlaminar shear mechanical behavior of unidirectional composites was independent of the thickness of the specimens,but the shear strength decreased with the increase of the thickness of the specimens.The image analysis results showed that the distribution law,size,concentration and irregularity of the pores in samples of different thicknesses were significantly different. The numerical analysis results of RVE showed that the damage was caused by the destruction of the fiber-matrix interface close to the pores,and the interlaminar shear strength of thick-section composites decreased with the increase of the maximum pore size under the same porosity. At the same time, pore concentration and porosity also have a significant effect on the interlaminar shear strength of the material. The above experimental and analytical results show that the size effect of the interlaminar shear strength of thick-section composite materials is related to the microscopic characteristic parameters of the mate

关 键 词：不规则孔隙 剪切强度 孔隙率 孔隙尺寸 孔隙集中度 损伤趋势 

分 类 号：V258[一般工业技术—材料科学与工程] TB332[航空宇航科学与技术—航空宇航制造工程]