Fatigue life assessment of electromagnetic riveted carbon fiber reinforce plastic/aluminum alloy lap joints using Weibull distribution

• Published in: International journal of fatigue 2017-12, Vol.105, p.180-189
• Main Authors: Jiang, Hao, Luo, Tong, Li, Guangyao, Zhang, Xu, Cui, Junjia
• Format: Article
• Language: English
• Subjects: Aluminum alloys; Aluminum base alloys; Carbon fiber reinforced plastics; Carbon fiber reinforcement; Crack propagation; Cracks; Cyclic loads; Electromagnetic riveting; Failure modes; Fatigue behaviors; Fatigue cracks; Fatigue failure; Fatigue life; Fatigue life assessment; Fracture mechanics; Fretting; Hysteresis loops; Lap joints; Life assessment; Load distribution (forces); Materials fatigue; Microstructure; Polymers; Reinforced plastics; Reliability engineering; Riveting; S N diagrams; Stress concentration; Weibull distribution
• ISSN: 0142-1123; 1879-3452
• DOI: 10.1016/j.ijfatigue.2017.08.026

[Display omitted] •The microstructural characteristics of CFRP/Al electromagnetic riveted joints were obtained.•The quasi-static shear behaviors for CFRP/Al electromagnetic riveted joints were investigated.•Two-parameters Weibull distribution was employed to analyze statistically fatigue results.•The hysteresis loop and fatigue fracture appearances were analyzed. Electromagnetic riveting (EMR) has received increasing attention asa new kind of riveting technique in engineering industry. In this paper, EMR process was used to connect carbon fiber reinforced plastics (CFRP) and aluminum alloy (Al) hybrid joints. The mechanical behaviors (including static and fatigue properties) of the electromagnetic riveted lap joints were comprehensively investigated. The microstructure observation and the mechanical property tests were conducted to evaluate the joints performance. The mechanical test results showed that the failure modes of shear specimens were bending of the Al sheet and damage of the CFRP sheet, which was caused by rivet squeezing effect under static loading. However, the failure mode of fatigue specimens under each stress level was all ruptured at the Al sheet and the fracture analysis showed that cracks firstly initiated around the hole of Al sheet. This was caused by the fretting wear between Al sheet and rivet under cyclic loading. Two-parameter Weibull distribution was employed to analyze statistically fatigue cycles results. The S-N curves were drawn for different reliability levels (10%, 36.8%, 50% and 90%) for engineering applications. In addition, Hysteresis loop analysis implied that the specimens had no obvious flaw after EMR.