高低温交变湿热环境下外加载荷对不同孔隙率CFRP 拉伸力学性能影响  

Influence of external loading on tensile mechanical properties of CFRP with different porosity under high and low temperature alternating humidity-heat environment

作　　者：贾近[1] 姜明 肖海英[1] 张东兴[1] JIA Jin;JIANG Ming;XIAO Haiying;ZHANG Dongxing(School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China;Shanghai Composites Science &Technology CO.,Ltd,Shanghai 201112,China)

机构地区：[1]哈尔滨工业大学材料科学与工程学院,哈尔滨150001 [2]上海复合材料科技有限公司,上海201112

出　　处：《哈尔滨工业大学学报》2019年第5期23-31,共9页Journal of Harbin Institute of Technology

基　　金：黑龙江省自然科学基金(E201311)

摘　　要：通过高低温交变加速湿热循环试验及有限元模拟,研究了孔隙率和外加载荷对CFRP层合板湿热拉伸力学性能及界面破坏机理的影响.通过控制模压压力,制备出3种孔隙率的层合板;加载载荷分别为层合板最大弯曲载荷的30%、40%和60%.结果表明,孔隙率的增大是导致CFRP层合板湿热老化后拉伸性能大幅下降的主要原因,孔隙率越大,湿热拉伸强度下降越多.外加载荷能加速纤维与树脂基体界面脱粘,使材料湿热拉伸性能进一步下降,而且对不同孔隙率的层合板影响程度不一样,其中影响最大的是孔隙率为0.08的层合板,其次是孔隙率0.04的层合板,影响最小的是孔隙率为0.11的层合板.并且载荷越大,影响也越大,但其对材料湿热拉伸性能的影响远不如孔隙率的影响大.使用ABAQUS软件建立有限元模型,计算得到了层合板的各层拉伸应力分布,结果发现湿热循环导致90°层承受的拉伸应力上升,因此容易发生基体开裂及纤维/基体界面脱粘,导致力学性能下降,这一结果与试验结果相一致.计算得到的拉伸力学强度变化趋势与试验结果相一致.The effects of porosity and external loading on hygrothermal tensile mechanical properties and interfacial failure mechanism of CFRP laminates were studied by high and low temperature alternating accelerated hygrothermal cyclical test and finite element simulation. 3 kinds of laminates with different porosities were prepared by controlling molding pressure. The load on specimen was 30%, 40% and 60% of the maximum bending load of laminates, respectively. The results showed that the increase of porosity was the main reason leading to the sharp decrease of tensile properties of CFRP laminates after hot-humid aging. The greater the porosity was, the more hygrothermal tensile strength decreased. The external load could accelerate the debonding of the interface between fibers and resin matrix, further degraded the hygrothermal tensile strength of the composites, and had different effects on the laminates with different porosity. Among of them, the most influential one was the laminate with porosity of 0.08, the second was the laminate with porosity of 0.04, and the least was the laminate with porosity of 0.11. And the greater the load, the greater the impact, but the influence of load on the hygrothermal tensile properties of the laminates was far less than that of the porosity. ABAQUS software was employed to simulate tensile properties of composite specimen. The tensile stress distribution of the laminates was investigated, and it was found that the tensile stress increased at 90 degree layer due to the hydrothermal cycle. Therefore, the matrix cracking and fiber/matrix interface debonding were prone to occur, resulting in the decrease of mechanical properties, which was consistent with the experimental results. The variation trend of tensile mechanical strength calculated by the ABAQUS software was consistent with the experimental results.

关 键 词：CFRP 孔隙率 弯曲载荷 湿热环境 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]