GLARE层板挤压渐进损伤分析
Progressive damage analysis of GLARE laminates under bearing load

对GLARE36/5层板进行挤压性能试验研究,采用超声C扫描、断口微距拍摄和扫描电子显微镜等方法观测GLARE层板挤压渐进损伤过程和最终破坏模式。结果表明:GLARE层板挤压起始损伤为铝合金塑性变形;损伤扩展阶段,0°纤维主要承受挤压正应力,铝合金塑性变形增大,铺层间分层起始并扩展;0°纤维屈曲折断后层内纤维基体损伤和分层损伤急剧扩展,层板最终发生挤压破坏。将GLARE层板挤压失效分为层内失效和层间失效,采用应变描述的Hashin准则和界面单元方法并引入金属塑性建立GLARE层板挤压渐进损伤数值模型,数值模型对层板损伤起始位置、分层产生位置、损伤演化过程、最终破坏模式及破坏载荷进行了预测,计算结果与试验结果吻合较好,说明该计算方法能够有效模拟GLARE层板挤压渐进损伤性能。 Test investigation enforcing bearing load was occupied on GLARE36/5 laminates. The bearing damage progressive and ultimate failure modes of GLARE laminates were observed using ultrasonic C-scan, fracture macro photography and scanning electron microscope. Results indicate that the bearing damage of GLARE laminates initially occurred as plastic deformation of aluminium alloy, while in the stage of damage extension, delamination in layer appears and develops due to larger plastic deformation of aluminium alloy and bearing normal stress is mainly carried by 0°fiber. After the buckling and fracture of fiber in 0°ply, the matrix damage and delamination progress rapidly. Finally, bearing failure of the laminates occurres. Bearing progressive damage numerical model was developed, in which bearing failure in GLARE laminates were classified as in-ply failure and inter-ply failure, modelled with Hashin criteria in strain form and cohesive element approach respectively, while considering metal plasticity. This model was used to predict the locations where in-ply damage and delamination occur firstly, the progression of damage, final failure modes and failure loads. The calculation results are in good agreement with test results, meaning that the calculation method is able to simulate the progressive damage of GLARE laminates under bearing load effectively.