钢筋混凝土梁抗冲击性能研究的细观数值模拟方法

A mesoscale numerical simulation method for anti-impact performance of RC beams

为更真实地描述钢筋混凝土梁在冲击荷载作用下复杂的破坏过程,结合混凝土细观结构非均质性,假定混凝土是由骨料颗粒、砂浆基质以及界面过渡区(ITZ)组成的三相复合材料,考虑混凝土细观组分的率效应,将钢筋网嵌入至素混凝土梁,建立了钢筋混凝土梁抗冲击力学行为研究的三维细观尺度数值模型。基于该数值分析模型与方法,研究了落锤速度对钢筋混凝土梁抗冲击性能的影响规律。将细观数值模拟结果与宏观模型结果以及已有试验结果进行了对比分析,包括破坏模式、冲击力、跨中位移以及支座反力等,发现模拟结果与试验结果吻合良好,验证了细观数值分析模型在钢筋混凝土梁抗冲击性能模拟中运用的可行性。

To describe the complex failure process of reinforced concrete( RC) beams subjected to impact loading accurately,a mesoscale numerical analysis method was established to explore the anti-impact performance of a RC beam considering concrete heterogeneity,strain rate effect of concrete mesocomponents,concrete being assumed as a 3-phase composite composed of aggregate particles,mortar matrix and interfacial transition zones( ITZs),and a web reinforcement being embedded into the plain concrete beam. Using the proposed simulation method,effects of dropping hammer velocity on anti-impact performance of a RC beam were investigated. The simulation results including failure modes,impact loading,mid-span deflection and support reaction were compared with those of the macro-scale simulation results and the published test results. It was shown that the simulation results agree well with those of tests; the proposed meso-scale numerical model and method are feasible for simulating anti-impact performance of RC beams.