Experimental and numerical study of localized pitting effect on compressive behavior of tubular members

• Published in: Marine structures 2020-07, Vol.72, p.102784-22, Article 102784
• Main Authors: Wang, Renhua, Guo, Haichao, Shenoi, R. Ajit
• Format: Article
• Language: English
• Subjects: Buckling; Columns (structural); Compressive column test; Compressive properties; Corrosion; Cracking (corrosion); Cracking (fracturing); Damage localization; Deformation; Deformation effects; Failure mode; Failure modes; Localized pitting damage; Modelling; Pits; Pitting (corrosion); Random pitting modelling; Shape; Slenderness ratio; Stochasticity; Strength; Tubular member; Ultimate strength; Ultimate tensile strength
• ISSN: 0951-8339; 1873-4170
• DOI: 10.1016/j.marstruc.2020.102784

Locally pitted tubular members are usually considered as stub columns to assess the ultimate strength. However, it is not suitable for those with relatively larger slenderness ratios as their failure behavior is more complex and closely related to corrosion features of localized pitting. This paper presents compressive column tests on locally pitted tubular members of a moderate slenderness ratio. Corrosion pits were artificially introduced on local surface of the members, forming corrosion patches with various corrosion features. A numerical modelling method was proposed to reproduce the test specimens. Localized pitting damage was proven to cause substantial declines in the load deformation capacity and ultimate strength, and have a significant effect on the failure mode. The failure of a pitted member is mostly initiated by local buckling after yielding occurs in the corrosion patch, concurrent with pitting closure, and even shear cracking of member wall due to the perforated pits. Moreover, shape change of the corrosion patch most likely results in the failure mode to alter from column buckling to local buckling or interactive buckling. The shape ratio of the corrosion patch is one of the critical factor to influence the ultimate strength of locally pitted members. The proposed modelling method is applicable for extensive stochastic simulations so as to develop an empirical formula and to clarify the probabilistic characteristics of ultimate strength. •Compressive column tests of locally pitted tubular members were carried out.•Localized pitting corrosion was modeled in detail using a novel modelling method.•Numerical modelling can reproduce experiments of locally pitted members.•Effects of size, location and shape of corrosion patches were clarified.