Numerical analysis of fatigue performance of CFRP–repaired steel plates with central inclined cracks. (15th April 2019)

• Record Type: Journal Article
• Authors: Li, Lingzhen; Chen, Tao; Zhang, Ningxi
• Is Part Of: Engineering structures. Volume 185(2019)
• Page Start: 194
• Page End: 202
• Publication Date: 2019-04-15
• Subjects: Mixed-mode fatigue crack -- Crack inclination angle -- CFRP repair -- Stress intensity factor (SIF) -- Fatigue life; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2019.01.128
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Within a specific inclination angle range, crack inclination angle had minor effect on fatigue life subjected to uniaxial tensile fatigue loading. Within this range, fatigue lives tended to be similar if the crack projection lengths on the direction perpendicular to the loading axis were identical. Beyond this range, fatigue life increased as inclination angle rose. Fatigue life difference of specimens with distinct inclination angles originated mainly in the early crack propagation period. Initial stress intensity factor can be changed by modifying the initial crack tip direction. Abstract: Previous experimental and numerical studies on central inclined cracked steel plates demonstrated that when the initial crack inclination angles range from 0° to 60°, fatigue lives are similar if the initial crack projection lengths on the direction perpendicular to the loading direction are the same. This is applicable to both unrepaired and repaired specimens. This numerical study extended the inclination angle range from 60° to 80° and was conducted on the stress intensity factor (SIF) and fatigue life of CFRP–repaired steel plates with inclined central cracks subjected to tensile fatigue loading. In the case of unrepaired specimens with a crack inclination angle of 0–70° and double-sided repaired specimens with a crack inclination angle of 0–60°, it was concluded that the crack projection length on the direction perpendicular to the loading axis is the main influence of fatigue life, even though the projection length is calculated from the crack length and inclination angle. Beyond these limits, there is an obvious increase of fatigue life as the crack inclination angle rises. To minimize the effect of mode II component of SIF on the crack tip, two tail slots perpendicular to the loading axis were induced in the front of the inclined crack tips. The tail slots caused the effective SIF to increase and this led to a reduction of fatigue life. However, the limits of the initial crack angle of fatigue life calculation did not change. The results of previous research were also compared to the findings of this study; they supported the conclusions to some extent.