【摘要】 为了研究大型石油储罐在地震载荷作用下发生象足屈曲时的临界载荷与理论计算值之间的差异成因,采用数值模拟方法分析大型石油储罐纵环焊缝、焊接次序等因素对象足屈曲临界载荷的影响.提出焊接残余变形可以看作圆柱壳壁上的初始几何缺陷,在一定程度上会减小大型油罐的象足屈曲临界载荷.利用固有应变有限元法建立考虑焊接残余应力及变形的大型油罐象足屈曲准静态计算模型,分析焊缝有无、焊缝类型、焊接残余应力和变形、焊接次序对油罐象足屈曲的影响.结果表明,焊缝的存在都在不同程度上降低了油罐的象足屈曲临界载荷;在相同的固有应变下,油罐象足屈曲临界载荷降低的程度与焊缝的类型有关;焊接残余应力和变形越大,象足屈曲临界载荷越低,焊接次序对油罐的象足屈曲临界载荷影响不大;焊接产生的残余应力及变形的存在使得油罐罐壁发生象足屈曲处的位置有了一定程度的提高.更多还原

【Abstract】 Influence of longitudinal weld,circumferential weld,and welding sequence on elephant foot buckling critical load of large oil storage tank under earthquake was analyzed using numerical simulation method in order to explore the difference between actual elephant buckling critical load with theory calculated value.Welding residual stress and deformation was proposed to be seen as initial geometrical defect of cylindrical shells,which can decrease elephant foot buckling critical load of large oil tank to some extent.A quasistatic elephant foot buckling model of large oil storage tank was established using inherent strain finite element method,which incorporates effect of welding residual stress and deformation.The effect of with weld or not,weld type,magnitude of welding residual stress and deformation,and welding sequence on elephant foot buckling critical load was analyzed.Weld has a negative effect on elephant foot buckling critical load,the extent to which the elephant foot buckling critical load reduced is depending on the weld type under the same imposed inherent strain;the larger welding residual stress and deformation is,the less elephant foot buckling critical load is;welding sequence has little effect on elephant foot buckling critical load;welding residual stress and deformation affect the buckling location of oil tank to some extent.更多还原