低速冲击下钢筋混凝土深梁抗冲击性能及其损伤评估

为研究钢筋混凝土深梁在低速冲击下的抗冲击性能和损伤机理,采用有限元软件ANSYS/LS-DYNA对不同冲击速度下深梁动力响应进行模拟.分析深梁的动态损伤过程及横截面的损伤分布,采用截面损伤因子对钢筋混凝土深梁的损伤程度进行定量评估;进一步分析边界条件、冲击位置对深梁抗冲击性能和损伤的影响.分析结果表明:建立的模型可以合理模拟低速冲击下深梁的动力响应;低速冲击下深梁先在局部范围内形成损伤,再向整体扩展,在回弹变形阶段冲击位置处局部损伤二次增大;冲击速度对深梁冲击位置附近的截面损伤程度影响显著;增强边界约束条件,能够提高低速冲击下深梁承载力,降低损伤程度;冲击位置对深梁的竖向变形和破坏位置有明显影响,但对损失程度影响轻微.

Impact resistance and damage evaluation of reinforced concrete deep beam under low velocity impact

In order to study the impact resistance and damage mechanism of reinforced concrete deep beams under low-speed impact, the structural response of deep beams at different impact speeds was simulated by finite element software ANSYS/LS-DYNA. The dynamic damage process and the damage distribution of the cross section of the deep beam were analyzed, and the damage of it was quantitatively evaluated by the section damage factor. The influence of boundary conditions and impact position on the impact resistance and damage of deep beams were further analyzed. The analysis results show that the model established is capable of simulating the dynamic response of deep beams under low-speed impact reasonably, under which circumstance, the damage is formed in local area firstly, and then, it expands to the whole structure, the local damage increases again at the impact position ultimately. The impact velocity has a significant influence on the local damage degree at the impact position. Strengthening boundary conditions can improve the bearing capacity of deep beams under low-speed impact and reduce damage degree. The impact position has a significant impact on the vertical deformation and damage position of the deep beam, while it has little influence on the damage degree.