Spot welding

About: Spot welding is a research topic. Over the lifetime, 12491 publications have been published within this topic receiving 89845 citations. The topic is also known as: Spot_welding.

Spot welding method and its device

Abstract: PROBLEM TO BE SOLVED: To prevent generation of expulsion and welding defects by actually applying a proper pressurizing force between members in a weld zone, in a spot welding method in which the weld zone of a liquid tank is held between a pair of electrode tips, pressurized and energized for welding. SOLUTION: In the servo gun electrode tips oppositely vertically arranged with a weld zone of a liquid tank in between, the upper electrode tip is advanced by a servo motor, pressurizing a weld zone (S4). With the inter- electrode distance detected based on the output signal of the servo motor (S5), and with the distance equalized to the total thicknesses of a work in the weld zone (S6), the pressurizing force to the weld zone by the electrode is detected and stored (S8). The weld zone is pressurized with the value in which the detected pressurizing force is added to the preset proper pressurizing force required for welding (S9, 10, 11).

Fatigue cracking and its influence on dynamic response characteristics of spot welded specimens

Abstract: X-ray imaging has been used to determine the fatigue crack growth behavior and failure mechanisms of spot welded specimens. Cracks critical to final failure of the tensileshear specimens studied are through-thickness plate cracks, which are usually initiated about 0.2–1.0 mm away from the edge of the nugget. In addition, frequency response functions (FRFs), obtained by impact hammer-accelerometer experiments throughout the fatigue process, show that the natural frequencies of these joints nonlinearly decrease with the growth of fatigue cracks. The three-dimensional finite-element analysis results for FRFs of uncracked and cracked spot welded joints are shown to be in good agreement with the experimental data. It is also shown that the fatigue cracks have different degrees of influence on different natural frequencies because of the location of cracks and vibrating modes. The results by both experiment and finite element analysis indicate that analysis of the variation of natural frequencies and vibrating modes may be used to study the fatigue crack propagating shape and the location of the fatigue crack.

Development of Friction Spot Joining

Abstract: This paper describes the fundamental procedure and joint properties of Friction Spot Joining (FSJ), a new spot welding method for aluminium and other light metal alloys. The process uses frictional heat between a joining tool and work piece as the heat source, and produces a solid phase joining by causing plastic flow of the material. Technological essences of the process including the joining tool, a prototypic FSJ equipment, and process parameters were first fundamentally established. Consequently, based on those results, FSJ systems for practical use have been produced. Furthermore, various properties of the friction spot joint including metallurgical structure, hardness distribution, and tensile strength were investigated.