MT300/KH420碳纤维/聚酰亚胺树脂复合材料层合圆柱壳高温承载性能

基于Donnell-Mushtali近似理论及热弹性理论，考虑结构热变形和材料高温性能衰减等温度影响因素，对MT300/KH420碳纤维/聚酰亚胺树脂复合材料圆柱壳在常温、420℃及周向210~420℃不均匀温度场等热载工况下的承载性能进行了理论分析。并引入一阶屈曲模态缺陷作为几何初始扰动，利用ABAQUS，采用非线性显式动力学方法完成对MT300/KH420复合材料圆柱壳在以上热载工况下的轴压稳定性有限元仿真计算，计算结果与理论分析较为一致。设计并开展MT300/KH420复合材料圆柱壳力-热载荷联合轴压试验，获得圆柱壳在以上热载工况下的破坏载荷和破坏模式。研究表明:高温工况下，力学性能衰减和温场不均匀引起的结构热变形是影响MT300/KH420复合材料圆柱壳轴向失稳载荷的主要因素。 

Load-bearing capability of laminated MT300/KH420 carbon fiber/polyimide resin composite cylindrical shell at high temperatures

Based on Donnell-Mushtali approximate theory, combined with thermal elasticity theory, the axial load-bearing capability of MT300/KH420 carbon fiber/polyimide resin composite shell at ambient temperature, 420℃ and circumferential temperature distribution of 210–420℃ were evaluated by analytical methods, taking into consideration of the thermal deformation of structure, material’s degradation and other terms at high temperatures. In addition, the FEM analysis model was established by ABAQUS, which introduced the 1st buckling mode generated by buckle analysis as the original imperfection, and then studied the axial stability characteristics of MT300/KH420 composite shells by non-linear explicit dynamic method. The instability load and buckling mode are both presented which agree with the results obtained by analytical method. Furthermore, a thermal-mechanical joint axial compression test was designed and implemented, thus the failure loads and modes were obtained at above thermal fields. The results indicate that the material’s degradation and asymmetry deformation caused by non-uniform thermal fields are principal factors which impact the load-bearing capability of MT300/KH420 composite shells at high temperatures.