冲击波和破片复合作用下RC框架结构损伤倒塌及防护技术研究

Study on damage-collapse and protection technology of RC frame structure subjected to synergistic effects of blast and fragments

基于有限元软件ANSYS/LS-DYNA建立钢筋混凝土框架结构、炸药、空气、破片的模型,研究RC框架结构在破片和冲击波作用下的损伤倒塌及防护加固技术。通过对爆炸荷载下框架结构的动力响应及破片侵彻混凝土的实验进行数值模拟,验证本构模型选取、研究方法、接触选择等的合理性。对框架角柱、边中柱、中柱在不同爆点处冲击波单独作用、冲击波和破片复合作用下,结构的毁伤破坏以及连续倒塌情况进行对比分析,并研究破片层数对框架结构损伤破坏及连续倒塌的影响。研究结果表明:在抗爆设计时,应考虑破片侵彻作用对结构的毁伤破坏;当炸药位于不同爆点时,结构的倒塌速率、倒塌面积存在差异;随着破片层数增加,结构的损伤破坏程度增大,倒塌速率加快;聚脲弹性体加钢丝网的联合防护方式能够明显提升结构的抗复合作用性能;在梁柱节点处沿梁长设置加固钢筋以及附加钢板,能够提高框架结构抗连续倒塌能力,防止结构的连续倒塌。

The models of reinforced concrete frame structure,explosive,air and fragments were set up based on the finite element software ANSYS/LS-DYNA.The damage-collapse and protection of RC frame structure subjected to the synergistic effects of blast and fragments were studied.Through the numerical simulation of the experiment of dynamic response of the frame structure under the explosion load and with fragments penetrating into the concrete,the rationality of the selection of the constitutive model,research method and contact selection were verified.The damage-collapse of corner column,side middle column and middle column of the RC frame under the action of shock wave alone and the combined action of blast and fragments at different explosion points were compared and analyzed,and the effects of multistory fragments on damage failure and continuous collapse of frame structure were studied.The results show that in the design of anti explosion,the damage and destruction of structure caused by fragment penetration should be considered.When explosives are located at different explosion points,the collapse rate and collapse area of the structure are different significantly.With the increase of the layer of fragments,the damage degree of the structure increases and the collapse rate speeds up.The anti-composite performance of the structure will be improved by adopting the union measures of high-strength steel wire mesh and polyurea elastomer.Strengthening steel bars and attaching steel plates along the beam at the beam-column joints can improve the anti-continuous collapse ability of the RC frame structure and prevent the continuous collapse of the structure.