【摘要】 系列实验结果表明,在较强的滑移爆轰加载下,许多金属材料的旋转柱壳会呈现一种奇特的单旋剪切失稳破坏模式———受驱动壳壁结构上众多剪切滑移带及断口取向一致化,在45°和135°两族剪切带中,出现一族占优的现象。通过高速分幅和X光照相对剪切裂纹在壳壁内、外表的生成发展图像的记录和碎片样品回收,结合过程应力分析,对微剪切断裂发展过程中环向和纵向关联的可能机制进行了分析讨论,但疑点仍较多。在分析柱壳的高应变率失稳行为时,对于与加载条件及几何构形紧密耦合的材料动载剪切强度、各向异性性质所扮演的角色需要进一步认识。剪切断裂的单旋与聚能罩内层无破坏的射流整体旋转现象表现方式和程度虽有差异,但可能有着共同本质,值得深入探索。更多还原

【Abstract】 The self-organized shear bands phenomena of cylindrical metal shells driven by sliding explosively loading in either outward or inward direction are discussed. By means of high-speed photograph, the processes of the appearance of initial shear bands and their developments on out and inner surfaces were recorded and the fractured surfaces of recovery specimen are analyzed, showing the longitude shear fracture cell characteristics typical for some metals, such as HR2. The mechanism of the exclusive selection of shear bands orientation remains unexplained about the correlation between the shear bands on a given periphery of cylinder section and between the shear bands along a generatrix of the explosively loaded cylindrical shell with respect to the short time delay before shear bands orientations to be fixed. This uniform selection of shear failure anisotropy from two alternatively groups (45°/135°with respect to the cylinder radii) under explosive loading seems not always related to initial metallurgical texture. It might have some common basic with jet spin phenomenon.更多还原