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.

Analysis of aluminum resistance spot welding processes using coupled finite element procedures

Abstract: A comprehensive analysis procedure has been developed to perform the incrementally coupled thermal-electrical-mechanical analysis to simulate the resistance spot welding process of aluminum alloys. Because aluminum has high thermal conductivity, low melting temperature and low yield strength, deformation resulting from resistance spot welding is expected to be more severe than for steel. Compared with most of the published work in this area, this paper takes into account the incremental changes in sheet-deformed shape, contact area and current density profile as well as large deformation effects. The present analysis procedures consider electrical contact resistivities to be not only functions of contact temperature but also functions of pressure. Joule heating at the contact surfaces is computed using an equivalent surface heat generation concept. This new procedure is suitable for analyzing many important parameters such as contact area changes, electrode movement and dynamic resistance, as well as other factors that contribute to weld quality such as weld size, weld indentation, sheet separation and weld residual stresses. It can also be used to study nugget development and analyze the mechanisms of electrode wear and weld cracking.

Formable light weight composites

Abstract: The present invention relates to light weight composite materials which comprise a metallic layer and a polymeric layer, the polymeric layer containing a filled thermoplastic polymer which includes a thermoplastic polymer and a metallic fiber. The composite materials of the present invention may be formed using conventional stamping equipment at ambient temperatures. Composite materials of the present invention may also be capable of being welded to other metal materials using a resistance welding process such as resistance spot welding.

On the calculation of the free surface temperature of gas-tungsten-arc weld pools from first principles: Part II. modeling the weld pool and comparison with experiments

Abstract: By combining a mathematical model of the welding arc and of the weld pool, calculations are presented to describe the free surface temperature of weld pools for spot welding operations. The novel aspects of the treatment include the calculation of the heat and current fluxes falling on the free weld pool surface from first principles, a realistic allowance for heat losses due to vaporization, and a realistic allowance for the temperature dependence of the surface tension. The most important finding reported in this article is that the free surface temperature of weld pools appears to be limited by Marangoni convection, rather than heat losses due to vaporiza-tion. Furthermore, it was found that once thermocapillary flow can produce high enough surface velocities (>25 cm/s), the precise nature of the relationship between temperature and surface tension will become less important.

Weld electrode for attractive weld appearance

Abstract: Weld faces of electrodes for resistance spot welding are formed with a suitable area of protrusions and/or intrusions. The size, shape, and elevation or depths of the protrusions or intrusions are determined for the formation of suitable spot welds in and between metal workpieces such as aluminum or steel panels for vehicle bodies. The protrusions or intrusions are also conceived and used to form an image on at least a visible surface of the welded article to produce an attractive appearance on the surface of the welded sheet.