冲击作用下带肋焊接工字钢梁动力响应和损伤研究

Research on dynamic response and damage of ribbed welded I⁃beam under impact

为研究冲击作用下焊接工字钢梁的动力响应和损伤,采用有限元软件Abaqus对不带肋和带肋三种构造形式的焊接工字钢梁在冲击荷载作用下的动力响应进行了数值模拟分析。通过与落锤试验结果对比,验证有限元模型的合理性。建立27个模型对冲击荷载作用下焊接工字钢梁的动力响应和损伤进行研究,分析了冲击质量、冲击速度、构造形式对焊接工字钢梁动力响应的影响,并分析其加速度响应和损伤程度。研究结果表明:随冲击速度增加,同一构造形式的钢梁其冲击力峰值和跨中残余位移增大;冲击质量对钢梁的峰值冲击力影响不大,但对其跨中位移影响明显;对于不同带肋间距的钢梁,其侧向位移和跨中残余位移随加劲肋间距的减小而明显减小;带肋钢梁的侧向位移比无肋钢梁小;带肋钢梁比无肋钢梁更有利于减小其跨中加速度,从而减小惯性力;基于最大位移评估指标建立以冲击质量、冲击速度为主控影响参数的损伤等级评估曲线,根据冲击质量、速度的组合点所在损伤等级评估曲线的位置,可快速判定冲击后焊接工字钢梁的损伤等级。

In order to study the dynamic response and damage of welded I⁃beams under impact,the finite element software Abaqus is used to numerically simulate the dynamic response of welded I⁃beams without ribs and ribs under impact loads.The rationality of the finite element model is verified by comparing with the results of the drop weight test.The 27 models are established to study the dynamic response and damage of welded I⁃beams under impact load.The impact mass,impact velocity and structural form are analyzed on the dynamic response of welded I⁃beams,and its acceleration response and damage degree are analyzed.The research results show that:with the increase of the impact velocity,the peak impact force and the mid⁃span residual displacement of the steel beam with the same structural form increase;the impact mass has little effect on the peak impact force of the steel beam,but it has a significant impact on its mid⁃span displacement.For steel beams with different rib spacing,the lateral displacement and mid⁃span residual displacement are significantly reduced with the decrease of the stiffening rib spacing.The lateral displacement of ribbed steel beams is smaller than that of non⁃ribbed steel beams.The ribbed steel beam is more conducive to reducing its mid⁃span acceleration,thereby reducing the inertial force.Based on the maximum displacement evaluation index,a damage level evaluation curve with impact quality and impact speed as the main control parameters is established.According to the position of the damage grade evaluation curve where the combination point of impact mass and velocity is located,the damage grade of damaged steel bean can be quickly determined.