Experimental study of the uniaxial compressive behaviour of DH36 steel plates with mechanically induced pits

摘要

Local discontinuities and stress concentrations from pitting corrosion on a component can significantly affect the mechanical properties and failure mode of a structure, even though the total mass loss from pitting is not prominent. To analyse these problems, experimental specimens are created from high-strength steel DH36. Tests are performed to analyse the compressive behaviour of plate specimens with different dimensions and pitting crater parameters. And the influence of the above parameters on the uniaxial compressive mechanical properties and failure mode of the test specimens are investigated. Furthermore, the volume loss rate is found to be the most suitable damage indicator for describing the degradation in mechanical properties of specimens with pitting. Based on the test results and classical constitutive model, a linear-exponential model for strength failure specimens and a bilinear model for buckling failure specimens are created using the volume loss rate as a variable. The compressive mechanical properties of plate specimens with different degrees of pitting damage can be predicted with these models. The results show that under compression, the specimen with pitting damage is more likely to exhibit buckling failure than the undamaged specimen, especially when the undamaged specimen is in or close to the critical buckling state.