单面贴补修理后层合板的拉伸性能
TENSILE BEHAVIOR OF COMPOSITELAMINATES WITHONE-SIDE BONDED REPAIR
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摘要: 对含孔损伤复合材料层合板单面贴补后进行拉伸试验研究。测量了层合板的应变分布、修理后层合板中心点的离面位移及拉伸强度等, 考察了补片的厚度、大小等因素对修理效果的影响。结果显示, 增加补片的厚度和直径能够提高母板的承拉能力, 但是增加补片的厚度会导致层合板离面位移增大。对无侧边支持的单面贴补层合板进行计算分析时, 必须考虑偏心载荷引起的弯矩的影响。在此基础上, 采用分层损伤判据建立了三维有限元模型, 对单面贴补层合板的破坏机理和拉伸强度进行了计算和分析。结果表明, 修理后层合板的拉伸破坏是由补片或母板内与胶接面相邻的层间分层引起的; 计算结果与试验结果一致。Abstract: The tensile failure mechanism of composite laminates with the damage of a hole was studied af ter beingrepaired with one-sided bonding. The out-of-plane displacement of the center point of the repaired laminates, tensilest rength and st rain dist ribution were measured. The influence of the patch size and thickness on tensile st rengthof the repaired laminates was examined experimentally. The result s demonst rate that increasing the patch thicknessand it s diameter can improve motherboard tensile st rength. However, enhancing the thickness of the patch will increase the out-of-plane displacement of the laminates. When undertaking computational analysis of one-side bondedlaminates without any support on the unloaded side, it is necessary to consider the effect s of the bending moment resulted f rom the eccent ric load. A three-dimensional finite element analysis was performed to detect the failure mechanism and predict the tensile st rength of the repaired specimens with delamination criterion. It was found that thefailure began in the first interface of the motherboard under the patch at the edge of hole or the patch. The analysisdata are good agreement with the test results.