航空复合材料-金属连接结构的拉伸性能及其渐进损伤

Tensile Property of Aeronautical Composite-Metal Joint Structure and Its Progressive Damage

利用有限元软件建立了某型飞机复合材料-金属连接结构件模型,以改进的Camanho损伤退化模型作为失效判定准则,模拟了该连接结构件的拉伸性能和损伤累积过程并进行了试验验证。结果表明:在加装防弯夹具后,复合材料-金属连接结构件的拉伸试验结果更加准确,拉伸破坏模式由拉脱破坏变为挤压破坏;在较小的拉伸载荷下,其应变随载荷的增加呈线性增大,在金属上的应变明显大于复合材料层合板上的;损伤从复合材料和金属连接螺栓处产生,随载荷的增大逐渐累积并沿螺栓挤压方向扩展;模拟得到的最终破坏载荷为90kN,与试验值的相对误差仅为6.5%,证明了模拟结果的准确性。

The model of the composite-metal joint structure of one type aircrafe was established using the finite element software.Then with the modified Camanho damage degradation model as the criterion of failure judgment,the tensile property and damage accumulation process of the joint structure were simulated and verified by the tests.The results show that after assembled with the anti-bending fixture,the tensile test results of the composite-metal joint structure were more accurate and the tensile damage mode changed from pull-off failure to crushing failure.Under relatively low tensile loads,the strain increased linearly with the increase of load and was obviously larger on the metal than on the composite laminate.The damage was produced from the connecting bolts between the composite and metal,then accumulated gradually and extended along the compressive direction of the bolts with the increase of load.The simulated final destruction load was 90 kN with the relative error of only 6.5%comparing to the test result,indicating the accuracy of the simulation.