Microstructural investigation and model of fatigue short crack in EH36 steels

Abstract

For better revealing the behavior and mechanism of fatigue short crack (SC) propagation, five different kinds of notched samples were designed. Based on the crack growth rate-SC length map, finite element method and electron backscatter diffraction (EBSD) pattern, the evolution theory of geometrically necessary dislocation density (ρ GND ) versus SC length was proposed to distinguish the physically short crack (PSC) length; Schmid factor was utilized to define the length of microstructurally short crack (MSC). Thus, the whole SC growth was divided into three parts: MSC, transition zone and PSC. Finally, an original piecewise model containing two parameters was proposed to describe the whole SC growth of EH36 steels.

A State‐of‐Art Review on Prediction Model for Fatigue Performance of Welded Joints via Data‐Driven Method

“…[1][2][3] As shown in Figure 1, fatigue performance is affected by several factors (material type, service environment, temperature, stress range, residual stress, weld defects, weld geometry, plate thickness, stress ratio, welding method, joint type, loading type, etc.). [4][5][6][7][8][9][10][11][12][13][14][15][16][17] In addition, the mechanism of fatigue fracture contains a large number of nonlinear relationships and the influencing factors (IFs) that are difficult to describe quantitatively. Additionally, welding is one of the most commonly used connection methods in engineering, and the fatigue fracture generally originates from welded joints.…”