摘要
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.
Experimental Study on Fatigue Damage of the Sandwich Structure with PMI Core under Cyclic Displacement Loading
ZHU Zhi-peng, YANG Feng-peng, LIN Qiao-yue （School of Naval Architecture, Ocean ＆ Civil Engineering, Shanghai Jiaotong University, Shanghai 200240, China） Abstract： In this paper, a lightweight sandwich composite composed of an aluminum panel and PMI polymer foam core used for magnetic suspension train vehicle body was selected as the subject of this study. The static strength test and fatigue experiment under displacement control were conducted on sandwich structures consisting of aluminum skin sheets and PMI foam core at room temperature. The fatigue behavior and failure behavior of PMI foam sandwich structure under cyclic displacement control are discussed, and the related static mechanics parameters were obtained. The fatigue test was conducted by applying appropriate displacement loading referring to the static test results. It is found that the fatigue damage process and failure mode of the sandwich structure under displacement control were significantly different from those under load control. For small displacement loading, the failure mode was mainly debonding between skin sheet and foam core. For large displacement loading, the failure mode was the fracture of skin sheet and the collapse of foam core. The damage evolution equation was established by introducing variation of loading as the damage parameter under displacement control mode. Kay words： PMI foam; sandwich structure; displacement control; fatigue life; damage assessment
出处
《力学季刊》
CSCD
北大核心
2017年第1期94-101,共8页
Chinese Quarterly of Mechanics
基金
国家自然科学基金(11102107)
上海市自然科学基金项目(16ZR1417700)
关键词
PMI泡沫
夹层结构
位移控制
疲劳寿命
损伤评估
PMI foam
sandwich structure
displacement control
fatigue life
damage assessment
