Damage and failure characteristics of CFRP/aluminum single lap joints designed for lightweight applications. (August 2020)

• Record Type: Journal Article
• Authors: Chen, Yiwei; Li, Maojun; Yang, Xujing; Luo, Weihao
• Is Part Of: Thin-walled structures. Volume 153(2020)
• Publication Date: 2020-08
• Subjects: Lightweight materials -- Joining -- Digital image correlation -- Failure mechanism -- Strain distribution; Thin-walled structures -- Periodicals; 690.1
• DOI: 10.1016/j.tws.2020.106802
• Languages: English
• ISSNs: 0263-8231

Abstract

Abstract: In this study, a full-factorial experimental design was employed for evaluating mechanical behavior of riveted, adhesively bonded and hybrid joints. The effects of significant design factors including overlap length, rivet diameter and adhesive thickness on progressive failure process of CFRP/Al6061-T6 single lap joints under quasi-static loads were investigated using high speed imaging technique. The complex strain distributions were evaluated using digital image correlation method. Results showed that load-displacement curves and failure process of hybrid joints presented two stages to prevent premature joint failure. Final failure mechanisms of hybrid joints were significantly affected by rivet diameter, while independent on overlap length and adhesive thickness. Various types of failure including severe adhesive and cohesive failure, fiber-tear failure and rivet fracture were found on damaged surfaces of hybrid joints using 3.0 mm diameter rivet, while joints using 5.0 mm diameter rivet were featured with flexural fracture of CFRP substrate. Highlights: Hybrid joint presented severe bending and out-of-plane displacement with DIC analysis. Peak load and energy absorption were highly affected by overlap length with statistical analysis. Overlap length and adhesive thickness had limited effect on failure modes. The complex strain distributions were analyzed using digital image correlation technique. Various failure mechanisms of different joining methods and design factors were analyzed.