A. Al-Samhan

Finite element modeling of weld-bonded joints

Abstract The present work aimed at predicting the strength of weld-bonded joints having square or spew fillet adhesive layer. For comparison purposes, adhesive bonded and resistance spot-welded joints were also included in this study. The present work demonstrated that, the major principal stress predicted in joints having spew fillet adhesive layer is lower than that predicted in joints having adhesive layer with square edges. Consequently, it is advised to use adhesive layer having spew fillet to strengthen weld-bonded joints.

Design rationale of weld-bonded joints

The aim of the present work is to study the most influential parameters governing the strength of weld-bonded joints. The thickness and elastic modulus of adhesive, the stress concentration factor and the adherent materials, were all considered and their effectiveness evaluated. The present work demonstrated that for rationale design of weld-bonded joints, adhesives with the less Youngs modulus available should be coupled with maximum permissible gap thickness.

Strength prediction of weld-bonded joints

The present work aimed at predicting the strength of weld-bonded joints. For comparison purposes, adhesive-bonded and resistance spot-welded joints were also included in this study. The present work demonstrated that, the major principal stress predicted in spot-welded joints is nearly five to six times, when compared with those associated with weld-bonded and adhesive-bonded joints, respectively The present work also demonstrated the effective role played by the adhesive layer in strengthening weld-bonded joints.

The computer simulation of cold-roll-forming using FE methods and applied real time re-meshing techniques

Abstract Cold-roll-forming (CRF) is an important sheet metal forming process. However, product design procedures, in terms of rolls design and rolls pass schedule, remains more an art than science. Finite element (FE) computer simulation can be used to predict the deformation and final product geometry, hence, reduce the design time and cost. The main objective of this work is to develop a FE models to simulate the CRF process, and to predict membrane strain distributions. The model was used to simulate CRF of a trapezoidal channel section, and the simulation results were compared to publish experiments. Two models were investigated in this paper, simulating strip rolling with friction was investigated using two FE models. The first model involves closing the rolls over the undeformed stock to predict the initial deformed mesh, as a first stage, followed by rolling, as a second stage. The second model involved a rolling simulation with a pre-deformed mesh until the deformation was fully developed. Furthermore, to decrease the computation time and to continue the rolling simulation, a technique using dual meshes and re-meshing was applied to simulate roll-forming trapezoidal channel section.

The development of real time re-meshing technique for simulating cold-roll-forming using FE methods

Abstract Cold-roll-forming (CRF) is an important sheet metal forming process. However, product design procedures, in terms of rolls design and rolls pass schedule, remains more an art than science. Finite-element (FE) computer simulation can be used to predict the deformation and final product geometry, hence, reduce the design time and cost. The main objective of this work is to develop a real time re-meshing technique that can be used to run and complete the computer simulation of CRF process. This will enable decreasing the computational time and predicting the final geometry of cold-roll-formed product. A real time re-meshing technique using dual meshes was developed and benchmarked by applying the technique on traditional flat stripe rolling with friction.