JJ160/41-K型钻井井架非线性稳定性分析

Nonlinear Stability Analysis of JJ160/41-K Type Oil Derrick

根据对JJ160/41-K型井架的结构分析,确定该井架的失稳类型属于极值点失稳,具有很强的非线性,在计算时需考虑结构几何非线性和材料非线性对结构承载能力的影响。应用ANSYS软件建立了井架有限元分析模型,对结构材料本构关系采用线性增强型的弹塑性模型。通过线性屈曲分析及非线性稳定性分析,得到结构临界载荷系数分别为4.21和2.44,计算结果表明,非线性稳定性分析可以更准确地评估出结构的稳定极限承载能力,采用非线性的分析方法更接近实际。

JJ160/41-K type oil derrick was widely used in Daqing oil field. On the basis of structure analysis, it is confirmed that instability problem for this type derrick belongs to extremepoint instability. Extreme-point instability has strongly nonlinear characteristics; effects of geometric and material nonlinearities to structure load capacity must be considered in structure analysis. Using software ANSYS build up the structure finite element analysis model, constitutive re lations of materials adopted linear strengthen elastic-plastic model. By linear buckling and nonlinear stability analysis, the structure critical load factor obtained, respectively, are 4.21 and 2.44, the results show that nonlinear stability analysis can more accurately evaluate the structure＇s load capacity limit. Nonlinear analysis method is more closed to practical structure and very necessary in evaluating the structure load capacity.