垂向载荷作用下的冰层破裂及其影响因素分析

Analysis of ice breaking under vertical loads and its influencing factors

为了研究冰层在垂向载荷作用下的破裂过程及其影响因素,应用显式动力学分析软件LS-DYNA,基于罚函数接触算法,开展圆柱体-冰层垂向相互作用下的数值模拟。分析了垂向载荷作用下冰层的破裂过程和裂纹扩展,以及圆柱体与冰层不同的相对速度、接触角度和接触面积对冰层突破载荷的影响。计算结果表明:冰层在垂向载荷作用下,当最大拉应力大于冰的抗拉强度时,冰层会相继生成径向裂纹和周向裂纹,径向裂纹产生时的突破载荷小于冰层最终破裂时的突破载荷;集中载荷作用下的冰层相比于均布载荷作用下的冰层更易发生破裂;不同相对速度下,冰层突破载荷曲线会有较明显变化;当圆柱体与冰层之间有接触倾角时,冰层的破坏模式会发生较大改变。

In order to study the fracture process of an ice layer under vertical loads and its influencing factors,the explicit dynamics analysis software LS-DYNA was used to carry out the numerical simulation of the interaction of the ice layer and rigid cylinder based on a penalty function contact algorithm.The fracture process and phenomena of the ice layer under different vertical load,relative velocity,contact angle,as well as contact area between cylinder and ice layer were analyzed.The results show that:when the maximum tensile stress is greater than the tensile strength of ice,the ice layer under the vertical load will generate radial cracks and circumferential cracks one after another,and the breaking load of radial cracks is less than that of the final ice layer breaking.The cracking of the ice layer under the concentrated load is more likely to occur than that under the uniform load.When there is a contact angle between the cylinder and ice layer,the failure mode of the ice layer changes significantly.