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论文选取磁悬浮列车车身所用的由铝面板与聚甲基苯丙酰亚胺(PMI)聚合物泡沫芯层所组成的轻质夹层复合材料为研究对象,对夹层结构在室温下进行静态强度测试和进行以位移为控制变量的疲劳损伤演化试验,探讨分析了PMI泡沫夹层结构在交变位移控制下的疲劳性能和破坏行为.给出了PMI泡沫夹层结构在静态载荷作用下的力学性能参数.参考静态试验结果加载适当的位移载荷进行疲劳试验,发现在位移控制模式下,夹层结构的疲劳损伤过程和破坏模式明显区别于载荷控制模式.当最大控制位移较小时破坏形式为面板与泡沫层脱离;位移较大时为面板断裂和泡沫芯层塌陷.通过引入载荷的变化作为损伤参量建立了位移控制模式下损伤演变公式,并对两种模式的破坏行为进行了较好的预测.
In this paper, the lightweight sandwich composite consisting of an aluminum panel and polymethyl-phenylpropionimide (PMI) polymer foam core used in the maglev train body is selected as the research object. The sandwich structure is tested at room temperature for static strength and The fatigue damage evolution of the PMI foam sandwich structure under alternating displacement control was investigated and analyzed, and the mechanical performance parameters of the PMI foam sandwich structure under static loading were given. The results of static test show that under the displacement control mode, the fatigue damage process and failure mode of sandwich structure are obviously different from that of load control mode.When the maximum control displacement is small, the failure mode is the detachment between the panel and the foam layer. When the displacement is larger, the failure of the panel and the collapse of the foam core layer are discussed. The damage evolution formula under the displacement control mode is established by introducing the change of the load as the damage parameter, and the damage behavior of the two modes is well predicted.