空心及PMI泡沫填充铝波纹夹芯梁冲击性能实验研究

Experimental Investigation on Impact Response of Aluminum Corrugated Sandwich Beams with Empty and PMI Foam Filling

为了提高油罐车罐体在冲击载荷下的强度和耐撞性,提出了两种三明治结构:空心和PMI泡沫填充率波纹夹心结构,来代替传统的均质结构,通过泡沫块冲击实验,对两种构型的三明治夹芯梁的冲击性能进行了研究。通过高速摄影观察了夹芯梁的变形过程,得出了在不同冲击速度下同质量不同芯体结构的夹芯梁后面板所产生位移的时程曲线,考察了两种类型夹芯梁在冲击载荷下的后面板中点位移及各自的变形特点。实验结果表明:空心波纹夹芯梁在速度较高的冲击载荷作用下,前面板在冲击区域发生撕裂,波纹芯体发生较大幅度的压缩;相对于空心夹芯梁,PMI泡沫填充夹芯梁前面板的撕裂和芯体的压缩程度大幅减小,但后面板中点位移较空心夹芯梁更大。由于结构的撕裂在罐车的行进过程中容易扩展并至更严重的破坏,因而填充夹芯结构相对空心结构更具优势。

Two corrugated aluminum sandwich structures with empty and PMI foam filling are proposed to improve the strength and crashworthiness of oil tank structure under impact loading, and to provide substitutes for traditional monolithic counterpart. Aluminum foam projectile impact test is conducted to investigate the dynamic performance of the sandwich beams with the two proposed configurations. High-velocity photography is employed to capture the features of the beam deflecting process. The deflection history at the mid-span of the back face, as well as the deformation and failure modes, is studied for different sandwich beams with same total weight. Experimental results show that when impact velocities are relatively high, the corrugated core of empty sandwiches is significantly compressed and the front face experiences large scale indentation and severe tearing, whereas both core compression and front face tearing in foamfilled sandwiches are significantly reduced as a result of foam filling. The back face deflection of a foam-filled sandwich is nonetheless larger than that of an empty sandwich. From a realistic point of view, the filled sandwich is preferable compared to the empty sandwich.