弯剪状态下铝合金板式节点的静力试验及有限元分析

Experimental investigation and FE analysis on aluminum alloy gusset joints subjected to combined bending moments and shear forces

为研究铝合金板式节点弯剪作用下的受力特性,对足尺试件进行静力加载试验.试验测得了板式节点的荷载-位移曲线、荷载-滑移曲线以及关键位置的应变.同时对节点试件进行了有限元分析,并将试验结果与数值计算结果进行了对比.研究结果表明:加载结束后,杆件承受的最大弯矩约为其纯弯状态下强度设计值的0.88倍;试件上盖板存在明显的传递路径和高应力区,而下盖板高应力区域主要集中在与主受力杆件顶端对应的位置;各工字铝构件总体上处于弹性工作状态,且杆端剪力通过腹板分别传递至上、下翼缘后经盖板传递至其他杆件;盖板和工字铝翼缘板间产生明显的相对滑移;垂直于主受力方向的环槽铆钉受力最为不利,呈剪切受力状态,但由于不锈钢的强度较高,并未出现铆钉破坏;板式节点的有限元分析结果与试验结果吻合较好,反映了本文有限元模拟方法的可靠性.

In order to investigate the mechanical characteristics of aluminum alloy gusset joint subjected to combined bending moments and shear forces,experimental and numerical study has been carried out.The load-displacement curves,the load-slippage curves and the strain at the concerned positions were measured.Finite element analysis（FEA）models were established.The results of experiments and FEA models were compared.The studies show that the ultimate bending moment is 0.88 times of the design strength of the member under pure bending.Stresses of the upper cover plate are relatively high and transfer in a clear path,while the high stresses in lower cover plate mainly distribute in the corresponding position of main bars.All I section aluminum members are basically in elastic working condition.The shear forces transmit to the upper and lower flange plate through web plate,and then the force sequentially transmit to other members connected to the joint through the joint cover plate.Relative slippage occurs obviously between the cover plates and the flange of I section aluminum.The lockboltsperpendicular to the direction of the main force are in shearing state under the most unfavorable loading state,but they have not been damaged because of the high strength of stainless steel.Numerical results obtained are verified by the experiment,which proves the reliability of the numerical model in this paper.