温度对缝合气凝胶夹芯复合材料面内压缩性能的影响

Effect of temperature on the edgewise compression properties of the stitched aerogel-core sandwich composite

分别开展缝合气凝胶夹芯复合材料在不同温度下的面内压缩试验,研究材料在室温、300℃、600℃和800℃下的面内压缩力学性能,并采用微焦点工业CT扫描的方法对试样内部结构进行分析,结合有限元分析方法,探究其结构破坏机制。结果表明:在面内压缩载荷作用下,材料存在极限载荷,面板的局部屈曲、芯层的剪切破坏以及缝线柱的断裂是材料破坏的主要方式。随着温度的升高,材料的面内压缩模量和极限载荷也逐渐升高,面板破坏处的断口逐渐呈现出类似脆性的断裂。300℃、600℃和800℃下材料的面内压缩模量分别为室温的1.05倍、1.57倍和1.65倍;极限载荷分别为室温的1.14倍、1.46倍和1.67倍。室温下有限元分析结果和试验结果的对比,验证了缝合气凝胶夹芯复合材料面内压缩破坏模式的合理性。

Edgewise compression experiments were conducted at different temperatures for the stitched aerogeb core sandwich composite, and the edgewise compression mechanical properties were investigated at RT, 300℃, 600℃ and 800℃, respectively. Micro-focus industrial computed tomography （Micro-CT） technology was adopted to scan the internal structure of the composite. And combined with FEM analysis method, edgewise compression failure mechanisms were discussed. The results reveal that in the case of edgewise compression, the composite has ultimate load. The local buckling of the panel, shear failure of the core and crush of the stitches are the main damage mechanisms of the specimens. With the increasing temperature, the edgewise compression modulus and the ultimate stress increase, and the fracture mode of the panel trends to be brittle. The compression modulus of 300℃, 600℃ and 800~C is about 1.05 times, 1.57 times and 1.65 times that of room temperature, respectively, and the ultimate strength is 1.14 times, 1.46 times and 1.67 times that of room temperature, respectively. The comparison of finite element analysis results and the experimental results at room temperature shows that the failure mode of the stitched aerogel-core sandwich composite is reasonable.