冲击荷载作用下混凝土的受力分析

溜井的稳定与否对矿山的生产有很大影响,既受静载作用,又受冲击荷载作用.冲击荷载是使其产生较高破坏率的主要原因.为了探求冲击荷载的作用,应用Hertz接触弹性分析,对钢球冲击下不同尺寸的混凝土试件进行受力求解;同时应用动力分析软件LS-DYNA3D对冲击过程进行数值模拟求解混凝土的受力.随着试件尺寸的增大,解析结果和数值模拟结果表明,虽然钢球的冲击能有所增加,但是试件受力增长缓慢;试验结果表明塑性变形能的尺寸效应越来越明显,导致了试件破坏时冲击次数的增多.

Stress Analysis of Concrete Under Impact Loading

The stability of a pass has great effect on the mine production,on which not only the static load but also impact load act.Among them the latter is the main cause of high rate of failure of the pass.To explore the effect of impact load on the pass,the contact elasticity analysis by Hertz is made to solve the stress in the concrete specimens of different sizes under steel ball impact,and the dynamic analysis software LS-DYNA3D is used to simulate numerically the impact process for the same stress.The two results are compared and reveal that the stress in specimens increases slowly with the increasing impact energy of steel ball especially the increasing size of specimens.It implies that the higher the plastic deformation energy,the more obvious the size effect,thus resulting in the fact that the specimen failure is due to the increase in the frequency of impact.