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钢结构设计规范GB 50017-2003规定箱形截面轴心受压构件板件宽厚比不应超过y40 235/f,但实际工程中板件宽厚比达到120,远远超过此值。该文采用ANSYS有限元软件建立模型分析了高强度钢(名义屈服强度为460MPa)宽厚比超限的焊接箱形截面轴心受压构件的极限承载力。分析中考虑几何缺陷(整体、局部初弯曲)和残余应力,以及几何非线性和材料非线性的影响。同时,采用曲线a代替规范GB 50017-2003中规定的曲线b,用直接强度法对这些构件进行计算,并将计算结果和有限元模拟结果相比较。针对误差较大的压杆,提出修正的直接强度法。研究表明:该文有限元模型能够很好地模拟高强度钢焊接箱形截面轴心受压构件非线性屈曲的性能;对板件宽厚比B/T≥45的轴心受压构件,有限元计算结果和直接强度法计算结果吻合较好,而对B/T<45者,二者相差较大;提出的修正直接强度法和试验结果吻合很好。
Steel Structure Design Code GB 50017-2003 provides box-section axial compression member plate thickness ratio should not exceed y40 235 / f, but the actual project board width to thickness ratio of 120, far exceeding this value. In this paper, ANSYS finite element software was used to establish a model to analyze the ultimate bearing capacity of welded box-sectioned axial compression members with high-strength steel (nominal yield strength of 460MPa). The analysis takes into account geometric imperfections (global, local initial bending) and residual stresses as well as geometrical and material nonlinearities. At the same time, curve a is used instead of the curve b specified in GB 50017-2003, and the direct strength method is used to calculate these components. The calculated results are compared with the results of finite element simulation. For the larger error bar, put forward a revised direct strength method. The results show that the finite element model can simulate the nonlinear buckling performance of high-strength steel welded box-section axial compression members well. The axial compression member with B / T ratio of 45, The calculated results are in good agreement with the results of direct strength method, but for B / T <45, the difference between them is large. The corrected direct strength method is in good agreement with the experimental results.