摘要
基于薄膜理论、试验数据和有限元法对大直径贮箱三心底在内压作用下的应力分布进行了分析比较,同时利用有限法对大直径贮箱三心箱底的弹性屈曲和塑性屈曲行为进行了计算分析,并对模态缺陷对塑性屈曲载荷的影响进行了研究。研究结果表明:三心底过渡区处于经向受拉、环向受压状态,应力波动较大,结构存在屈曲的可能;塑性屈曲载荷与模态缺陷幅值成反比,模态缺陷能有效降低塑性屈曲载荷;D/t、r/D、Rs/D三个参数对弹性屈曲载荷和塑性屈曲载荷的影响规律基本一致,Rs/D、D/t与屈曲载荷成反比,r/D与屈曲载荷成正比;当D/t和Rs/D在一定参数区间内,三心底将不会发生塑性屈曲。
Based on the membrane theory, the test data and the finite element method, the stress distribution of the large diameter tank three-center bottom was analyzed comparatively in this paper. The elastic and plastic buckling behavior of the large diameter tank three-center bottom were calculated by the membrane theory, and the effects of the mode imperfection to the plastic buckling load were studied. Thefollowing conclusions can be drawn from the analysis results. The transition region of three-center bottom is in the state of warp tension and toroidal pressure, and the stress is fluctuating,the transition region of three-center bottom should be bucking . The buckling load is inversely proportional to mode imperfection amplitude, and the mode imperfection can effectively reduce the plastic buckling load. The influence regular of the three parameters, D/t, r/D and Rs /D to the elastic and plastic buckling load is basically identical, the buckling load is inversely proportional to Rs /D、D/t, and proportional to r/D. If D/t and Rs /D are in a fixed parameter range, the plastic buckling of the three-center bottom should not occur.
出处
《强度与环境》
2016年第6期29-37,共9页
Structure & Environment Engineering
基金
总装预研重点项目航天箭体结构优化减重设计的关键技术(625010345)
民用航天大推力运载火箭结构轻质化设计技术
关键词
三心底
力学性能
弹性屈曲
塑性屈曲
模态缺陷
three-center bottom
mechanical properties
elastic buckling
plastic buckling
mode imperfection
