CFRP加固钢筋混凝土板爆炸冲击作用下动力响应分析的数值模拟

Numerical simulation of dynamic response analysis of reinforced concrete slabs strengthened with CFRP under blast load

运用LS-DYNA非线性有限元软件,建立分离式钢筋混凝土板及CFRP防护材料的三维有限元模型,使用罚函数法实现钢筋-混凝土-CFRP材料的非线性耦合作用;采用ALE多物质流-固耦合算法对比分析普通钢筋混凝土板和外贴CFRP材料的钢筋混凝土板在爆炸冲击荷载作用下的动力响应特性,研究CFRP材料在爆炸荷载作用下对于钢筋混凝土板的防护机理,对比分析CFRP外贴材料厚度、CFPR外贴材料形式对钢筋混凝土板的动态响应的影响,并通过现有试验成果证明了数值模拟的可靠性。研究结果表明,CFRP材料起到的作用更多是增强钢筋混凝土结构的整体性,而不是降低高压冲击波对于混凝土结构的损伤效应,外贴CFRP条带可以明显延缓混凝土裂缝的发展趋势,延缓结构的破坏时间。CFRP材料真正发挥其作用是在混凝土裂缝扩展的后期,并且CFRP外贴材料越厚,在爆炸冲击荷载作用下,这种抵抗混凝土区域裂缝扩展的效果越明显。不同外贴形式的CFRP材料对钢筋混凝土板的影响具有差异性,中间加密型的防护效果最好、均匀分布型防护效果次之、边缘加密型的防护效果相对较差。研究结果可以为钢筋混凝土结构抗爆设计提供参考依据。

By using nonlinear finite element software LS-DYNA,this paper established a three-dimensional finite element model of separated reinforced concrete slabs and CFRP shields.This paper used the penalty function method to realize the nonlinear coupling between reinforcement and concrete and CFRP material.Comparison and analysis research on the dynamic response characteristics of ordinary reinforced concrete slab and reinforced concrete slabs affixed with CFRP material respectively under blast loads are given in this paper byμsing ALE multi material coupling algorithm.The protection mechanism of CFRP material to reinforced concrete slabs under explosive loading is studied in this paper.The effects of the thickness of CFRP and the forms of CFPR on the dynamic response of reinforced concrete slabs are discμssed in details.The reliability of the simulation is proved by the existing experimental results.The result show that CFRP materials play a major role in enhancing the integrity of the reinforced concrete structure,rather than reduce the damage effect of shock wave for the concrete structure.The development trend of concrete cracks can be significantly delayed by sticking CFRP strips outside,and delay the damage time of the structure.CFRP material really plays its role in the later stage of concrete crack propagation,and the thicker the CFRP sticking material is the more obvioμs.It is to resist the crack propagation in concrete zone under blast load.The CFRP strips with different forms have great influence on the reinforced concrete slabs,and the intermediate encryption type has the best protection effect,second by the uniform distribution and the edge encryption.The results of the research can provide reference for anti-explosion design of reinforced concrete structures.