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Quasi-static tests of spot welded and weld-bonded joints with 1.5 mm-thick SUS304 stainless steel sheets were conducted. Joint weld diameters were measured using scanning acoustic microscopy. Fatigue tests were performed to obtain the fatigue lives of two joint types subjected to different stress levels. The equations of load-life curves were obtained by nonlinear regression using a three parameter power function. Scanning electron microscopy was used to explore fatigue failure mechanisms of the joints. The results illustrate that nugget diameters of weld-bonded joints were smaller than those of spot welded joints. Their shear strength was lower, but weld-bonded joints showed a better fatigue performance than that of spot welded joints. Two fatigue failure modes were observed via testing: eyebrow failure mode and substrate fracture. [ABSTRACT FROM AUTHOR]

Self-piercing riveting (SPR) and clinching are new high-speed mechanical fastening techniques which are suitable for point joining lightweight sheet materials. The joinabilities of copper alloy H62 by SPR and clinching are discussed in this paper. Mechanical tests were conducted to study the static and fatigue properties of joints, and the properties of joints using SPR and clinching technologies were investigated. The effectiveness of experimental data was validated statistically, using Student's t test and a two-parameter Weibull distribution. The fatigue load ( F ) and fatigue life ( N ) results were plotted against log–log axes. Lines were fitted using least square methods and the two-parameter power function equations of F – N curves were obtained. The results showed that SPR joints had superior static and fatigue properties, but the clinched joints also presented favorable fatigue performance. [ABSTRACT FROM AUTHOR]

As a well-established modern manufacturing process, laser welding is widely adopted in different industry fields to assemble lightweight structures. Major advances have been made in recent years in laser welding. This article reviews the latest development of finite element analysis of laser welding, in terms of process, damage modeling, fatigue behavior, dynamic characteristics, and laser hybrid welding. Some important numerical issues such as materials modeling, meshing procedure, and failure criteria are discussed. Finite element analysis of laser welding will allow many different laser welding processes to be simulated in order to perform a selection of different system parameters before testing, which would be time-consuming or be prohibitively expensive in practice. The main methods used in finite element analysis of laser welding are discussed and illustrated with brief case studies. [ABSTRACT FROM AUTHOR]