结构非线性特性对金属蜗壳结构应力影响分析

Analysis on influences of nonlinear characteristics on stress of steel spiral case structure

应用ABAQUS有限元软件,结合实际工程,对不同埋设方式蜗壳进行了三维非线性有限元计算,分析了各种结构的非线性特性对蜗壳结构受力状态的影响。结果表明,垫层蜗壳结构中,接触非线性特性考虑与否对数值分析结果影响较大,而是否考虑混凝土的开裂非线性则影响较小;直埋蜗壳结构中,混凝土采用弹塑性模型时,钢衬应力水平相比采用线弹性模型可提高50%以上,混凝土结构开裂非线性对数值分析结果影响明显,而是否考虑钢衬与混凝土间接触非线性特性,则对数值分析结果影响较小。明确各种结构非线性特性对数值计算结果的影响程度,能便于工程设计人员更为有效地利用数值分析手段进行蜗壳结构设计。

By software of ABAQUS, three dimensional nonlinear finite element calcnlations on spiral case embedded in different manners are carried out for a practical case and the influences of various nonlinear characteristics on stress of steel spiral case structure are analyzed. For spiral case structure with cushion layer, the influence of contact nonlinear characteristic on numerical analysis result is significant, while cracking nonlinear characteristic is not obvious. For complete bearing spiral case structure, when elastic - plastic institutive concrete model is adopted, the stress of steel lining is 50% larger than the results calculated by elastic concrete model, furthermore, the influence of cracking nonlinear characteristic on numerical analysis result is significant, but the influence of the nonlinear characteristic of contact between steel lining and concrete can be ignored. The influence of different nonlinear characteristics on the calculation results were made clear.