常温下局部加载拉应力对柱壳应力场分布的影响

研究采用有限元模拟技术,考察常温局部加载条件下,加载宽度和试样尺寸对柱壳应力场分布的影响,揭示应力场的变化规律及机理.在常温下,柱壳结构局部受轴向外载拉伸时,随结构体长度的增加,在距加载区越远的横截面上应力分布越均匀;随加载宽度的增加,在结构体的中截面上应力最大值逐渐增加.当外加载荷大小、加载宽度及结构体长度相同时,柱壳结构中截面上拉应力最大值大于平板.因此可以预见,对于应用局部加载降低结构体焊接残余应力,柱壳结构要比平板结构效果更好.

Effect of Local Loading on Distribution of Cylindrical Shell Stress Field at Normal Temperature

With the FEM simulation technology,under the condition of local loading at normal temperature,effect of loading width and dimensions of specimens on distribution of stress field for cylindrical shell structure is investigated and rules and mechanism of the stress field are revealed.At the normal atmospheric temperature,when the cylindrical shell structure is drawn outward along the shaft axle,with an increase in the length of the structure,the stress distribution will be more uniform on the cross-section far from the loading area.The farther,the more uniform.With an increase in the loading width,the stress on the center of cross-section will grow.When their loading sizes,widths and lengths are the same,the maximum value of stress at the center of cross-section will be greater than that of the plane structure.It can be predicted that the cylindrical shell structure is better than the plane structure in reducing welding residual stress through local loading.