预应力加固砌体结构有限元模拟研究

Finite element simulation of prestressed masonry structures

由于整体式建模方法不能模拟砌块和砂浆之间的摩擦作用,导致模拟得到的滞回曲线在耗能上与试验结果相差较大。为解决这一问题,采用MSC.Marc有限元软件对某预应力加固二层砌体结构进行整体式建模时,在砌体结构的分层壳单元中增加一层强度极低的类似软钢的材料,结果表明,增加的软钢材料可以在几乎不提高结构承载力的前提下增加耗能能力,使模拟得到的滞回曲线与试验结果吻合良好。在此基础上,对结构进行改变预应力值的参数分析,结果表明,预应力筋对墙体施加0.13MPa的压应力时可将结构的整体抗震承载力提高6%,且结构的抗震性能随着预应力值的提高而增加。

Because the integral modeling method cannot simulate the friction between the block and mortar,the hysteretic curve obtained by simulation differs greatly from the experimental results in terms of energy dissipation.Therefore,adding a layer of extremely low strength soft steel material to the layered shell element of the masonry structure,when the finite element software MSC.Marc is used for the integral modeling of a prestressed two-story masonry structure,the results show that the additional mild steel material can increase the energy dissipation capacity of the structure almost without increasing the bearing capacity.On this basis,the parameter analysis of changing the prestress value of the structure shows that the seismicbearing capacity of the structure can be increased by 6%when the prestress reinforcement applies the compressive stress of 0.13 MPa to the wall,and the seismic performance of the structure increases with the increase of the prestress value.