加腋梁对RC框架结构的抗连续倒塌模拟分析

Simulation analysis of Progressive collapse of RC frame structure with haunched beam

为研究加腋梁对RC框架结构的抗连续倒塌能力,文章使用有限元软件ABAQUS进行建模,设计了九个不同尺寸加腋的三层四跨RC框架。采用拆除构件法,在拆除底层中柱和边柱的情况下进行非线性静力分析。结果表明加腋梁框架在拆除底层中柱时均未发生倒塌,且加腋梁框架KJ-L1的抗倒塌能力最好;拆除底层边柱时,未加腋框架及加腋框架均倒塌,但加腋梁框架倒塌时,框架整体的水平位移很小;加腋梁有利于节点区塑性铰的转移,使得框架在梁机制阶段的承载能力明显提升;加腋长直角边C1对中柱柱端竖向位移起着决定性影响———C1越大中柱柱端竖向位移越小。

In order to study the Progressive collapse resistance about haunched beam to the RC frame structure,nine different sizes of haunched three-story four-span RC frames are designed by using finite element software ABAQUS.Using the method of dismantling the components,the non-linear static analysis is carried out with the middle and side column of the bottom floor removed.It shows that the haunched beam frames have no collapses without the middle column of the bottom floor,and the haunched beam frame KJ-L1 has the best collapse resistance;Both the un-haunched frame and the haunched frame collapse when the middle column of the bottom floor are removed.However,when the haunched-beamed frame collapses,the overall horizontal displacement of the frame is very small.The haunched frame profits the transfer of plastic hinges in the joint area,which makes the frame’s load-bearing capacity at the beam mechanism stage significantly improved;Long right-angle side of the haunched C1 has a decisive influence on the vertical displacement of the middle column end———the larger C1 is,the smaller the displacement is.