强冲击载荷下边界对固支方板的毁伤破坏试验

冲击载荷作用下边界条件对方板的毁伤破坏具有很大影响。利用落锤试验机开展了不同边界支撑下固支方板的冲击试验,为获取固支方板边界撕裂的典型破坏模式,专门设计加工了与固支方板尺寸相当的冲击锤头和可改变倒角的方板支撑框架。研究结果表明:(1)冲击载荷作用下,固支方板呈现出塑性大变形、单边撕裂、双边撕裂等典型破坏模式,倒角越小,方板越容易撕裂;(2)边界支撑对固支方板中心位移、整体变形轮廓影响较小,但对方板的撕裂长度、临界撕裂阈值存在较大影响;(3)不同边界支撑主要改变方板边界处的剪切应变,边界支撑倒角越小,剪切效果越明显,方板边界临界撕裂应变位于0.191,0.241]区间。

Failure of Square Plate under the Influence of Boundary Conditions Subjected to Shock Loading

Boundary condition exerts great influence on the failure mode of square plate under intensive loading.In this paper,a series of experiments of clamped square plates with different boundary chamfer radius were performed in the drop hammer impacting machine,in which the drop hammer was specially designed nearly same as the square plate in dimension and the supporting framework could offer various boundary conditions.The results show that:(1)the failure mode of large plastic deformation,one-side tearing and double-side tearing can be observed,and the square plates are more easily damaged under smaller boundary chamfer radius.(2)The boundary chamfer radius has a minor effect on the plate center displacement and deformation profile,but a major influence on the boundary tearing length and crack forming process.(3)The shear effect on the boundary region of clamped square plate would decrease with increasing boundary chamfer radius,and it is more easier for the plate with smaller boundary chamfer radius to get torn under the same intense impulsive loading.The critical failure strain of square plate is among0.191,0.241].