MAY 2003 -S 116 ABSTRACT. Mechanical characteristics of resistance spot welding machines, such as stiffness, friction, and moving mass, have complex influences on the resistance welding process and weld quality. In this paper, these influences are systematically investigated through experiments. The mechanisms of the influences are explored by analyzing process signatures, such as welding force...

In this research, a method for implementing automatic seam-tracking for friction stir welding, referred to hear as WeaveTrack, is presented. In this extrumum-seeking control technique, the tool weaves back and forth during welding to maintain the location where axial force is greatest, which is shown to be the center of the weld. Results demonstrate the effectiveness of this technique in tracki...

Welding is a reliable and effective metal fabrication process which is widely used in industries. High heating at a one location during welding and further rapid cooling generates residual stress and distortion in the weld and base metal. In last few decades various research efforts have been directed towards the control of welding process parameter aiming at reducing residual stress and distor...

Distribution of residual stresses arising after welding is quite complex and inhomogeneous. Many factors have influence on the magnitude and the profile of the stress distribution curve. In the present paper an x-ray technique was used to analyze the residual stress distribution in steel sheets jointed by industrial welding with linear or circular weld seams. Interpretation of experimental resu...

formability of automotive friction stir welded twb (tailor welded blank) sheets isnumerically investigated in biaxial stretching based on hemispherical dome stretch (hds) test infour automotive sheets of aluminum alloy 6111-t4, 5083-h18, 5083-o and dp590 steel, havingdifferent thicknesses. the effects of the weld zone modeling and the thickness ratio on formabilityare evaluated. in order to car...

T-joint fillet welds are a very common occurrence found in industry today. Localized heating and cooling from the welding process lead to the rise of distortion and residual stresses. Weld fixturing is a common practice in industry used to address the problems associated with welding, however fixturing also creates problems of residual stresses being locked into the weldment. This research invo...

Aluminum alloy welding suffers from problems such as solidification cracking and hydrogen-induced porosity, which are sufficiently severe to limit its potential applications. Because mitigated porosity incidence and solidification cracking are observed in aluminum welds using double pulsed gas metal arc welding (DP-GMAW), a comprehensive review of the mechanism is necessary, but absent from the...

watermelon is handled and stored in bulk package as some other fruits and vegetables are. package height must be so appropriately selected that bottom fruit layers will receive no damage or failure. this research was performed to determine and compare the mechanical properties of two varieties in three sizes of watermelon under static load conditions to obtain parameters used in transportation ...

Resistance spot welding is an important manufacturing process in the automotive industry for assembling bodies. The quality and strength of the welds and, by extension, the body is mainly defined by the quality of the weld nuggets. The most effective parameters in this process are sheet material, geometry of electrodes, electrode force, current intensity, welding time and sheet thickness. The p...

Ill EXECUTIVE SUMMARY IV