爆炸载荷下地下钢管道混凝土围岩结构损伤效应数值模拟

摘要

采用LS-DYNA有限元软件对某地下钢管道混凝土围岩结构的抗爆炸冲击响应进行了数值模拟。对混凝土结构模拟采用 Holmquist模型、Malvar模型和 RHT模型；对花岗岩结构的模拟则根据实测数据拟合了 Holmquist模型参数。理论分析比较了3个模型的特点，并结合实际工况要求得出结论：1）Holmquist模型和 Malvar模型、RHT模型均能较好地模拟混凝土结构在爆炸载荷下的损伤效应，但Holmquist模型更适用于模拟压缩损伤，后两个模型模拟拉伸损伤更为合理；2）须根据实际工况和工程目标对各模型预测的损伤分布结果进行判定、取舍，获得更为准确信息；3）对混凝土材料性质未知或知之甚少的典型工况，可使用多个本构模型进行数值模拟对比分析，能够快速、全面地把握结构响应特征。%A numerical simulation was performed with the code LS-DYNA on an under-ground steel pipeline-concrete-rock structure under explosive loading.The Holmquist mod-elthe Malvar model and the RHT model were employed respectively for the concrete struc-turewhile for the simulation of granite structurethe parameters of the Holmquist model were obtained from the test data.The computation results indicate that the damage distribu-tions predicted by the three models are very different from each otherwhich can hardly sat-isfy the requirements of the engineering design.We theoretically analyzed and compared the distinguishing features of the three modelsand got the following conclusions1All of the three models can well predict the damage effects of concrete structure under explosive load-ingbut the Holmquist model is adept at simulation of compressive damagewhile the other two are more rational in describing tensile damage2In order to obtain more exact informa-tionthe predicted results of damage distribution with the three models should be determined according to the practical circumstances and proj ect obj ectives3In the case that the con-crete material is uncharacterized or little information about the concrete material is availablemultiple concrete constitutive models such as the simple input models are more helpful.