局部腐蚀下钢圈限位装置力学性能及使用年限预测

Mechanical Behaviour and Service Life of a Novel Steel Ring Restrainer with Local Corrosion

目的研究局部腐蚀后钢圈限位装置的力学性能,建立承载力退化比计算公式,并提出该装置使用年限的计算方法。方法通过改变腐蚀率与腐蚀区域建立210个局部腐蚀钢圈限位装置有限元模型。通过有限元分析得到不同腐蚀率下、不同区域出现局部腐蚀后钢圈限位装置刚度、极限承载力与极限位移等力学性能。量化分析腐蚀率及腐蚀区域对其力学性能的影响。结果随腐蚀率增加,钢圈限位装置的极限承载力显著下降,但其极限位移与刚度变化微小。腐蚀率相同情况下,随腐蚀区域改变,钢圈限位装置的极限承载力退化明显。结论腐蚀敏感区能反映局部腐蚀区域对钢圈限位装置极限承载力的影响。承载力退化比与使用年限计算式能有效预测局部腐蚀钢圈限位装置的承载能力与使用年限。

The purpose of this paper is to explore the mechanical behavior of steel ring restrainers(SRR)with local corrosion damage,build formulas of the ultimate strength degradation ratio,and propose the calculation method of the service life of SRRs.A total of 210 finite element(FE)models of locally corroded SRRs were established by changing corrosion rates and corrosion regions.Then the stiffness,ultimate strength,and ultimate displacement of the SRRs corroded in different regions were obtained from FE analyses under different corrosion rates.Subsequently,the influence of corrosion rates and corrosion regions on the mechanical performance of SRRs were studied.The results show that,as the corrosion rate increases,the ultimate strength of SRRs degrades obviously,but the ultimate displacement and stiffness varies slightly.Under the same corrosion rates,the ultimate strength of SRRs degrades obviously with the variation of corrosion regions.The corrosion sensitive regions can reflect the influence of local corrosion regions on the ultimate strength of SRRs.The formulas of ultimate strength degradation ratio and service life can effectively predict the bearing capacity and service life of SRRs with local corrosion.