Forming-limit diagrams of aluminum tailor-welded blank weld material

Abstract

The current work develops forming-limit diagrams (FLDs) for weld materials in aluminum tailorwelded blanks (TWBs) under biaxial stretching conditions. Aluminum TWBs consist of multiplethickness and alloy sheet materials welded together into a single, variable-thickness blank. The manufacture of TWBs and their application in automotive body panels requires their constituent weld material to deform under biaxial loading during sheet-metal stamping. The weld geometry is typically nonuniform and relatively small, causing difficulty if one attempts to determine the weld metal FLDs via traditional experimental methods. The subject work primarily relies on theoretical FLD calculation techniques using the Marciniak and Kuczynski (M-K) method. This numerical technique requires the use of material constants and levels of initial material imperfection that have been experimentally determined using unique miniature tensile specimens to isolate and characterize the weld metal. The experimental and numerical work, together with statistical analysis of the level of initial imperfection, allows generation of both an average and safe FLD. The weld metals studied in this work were produced via autogeneous gas tungsten arc welding of a 1-to 2-mm-thick 5000 series aluminum alloy sheet.

Crashworthiness analysis and multiobjective optimization for circular tubes with functionally graded thickness under multiple loading angles

“…These thin-walled structures have the same wall thickness, but their inherent weakness is that they are not able to make full use of the material to meet the requirements for lighter weight. 5 Therefore, it is widely considered that a new structure with varying thicknesses should be used to improve material usage. Tailor rolling blanks (TRBs), which lead to a continuous thickness variation in a workpiece, have been developed in recent years.…”

Hot stamping of AA6082 tailor welded blanks: experiment and FE simulation

“…Many studies have concentrated on the mechanical properties of TWBs [3], the movement of weld line [4], forming process design [5], finite element simulation [6], forming limit (formability) [7] and failure prediction for TWBs [8]. Generally, the overall formability of TWBs is significantly affected by the welding parameters [9], especially for heat-treatable aluminium alloys.…”

Effect of Manufacturing Processes and Welding Type on Quasi-static and Dynamic Responses of Aluminum Alloys: Experiments and Modeling

“…Further, negative strain rate sensitivity was observed at all strain rates. Davies et al [10] reported their work in developing theoretical forming limit diagrams (FLDs) for weld materials. They used power law along with the Hosford yield criteria to obtain right-hand-side of FLD.…”