An innovative methodology for the thermomechanical simulation of the infrared heating diaphragm forming (DF) process is proposed. In the first section of the paper, the heat transfer mechanisms between the infrared (IR) heating lamps and the thermoplastic plate are simulated, and the effect of the various preheating parameters on the heating time and temperature distribution is investigated. In the second section, the mechanical deformation of the thermoplastic component is simulated to enable prediction of heat losses due to the plate contact with the mold. Based on the developed simulation methodology, the main process parameterse.g., the number, location, and power of IR lamps for optimal preheating; the heat losses during plate deformation; and the minimum required mold temperature throughout the forming phase -are derived for five different thicknesses. The optimization results show that the forming parameters considered influence the heating of the plate in a complex and interactive way; in addition, it is found that with increasing plate thickness, the heating time required to reach the desired temperature also increases.

Formability of Magnesium alloys is limited especially at room temperature due to their hexagonal close packed (HCP) structure. At room temperature (RT), the critical resolved shear stress for non basal slip systems is much greater than those for basal slips. As only basal systems may contribute to plastic deformation, magnesium alloys have limited formability at RT. However, increased formability is observed at higher temperatures ranging between 150 0 C and 300 0 C due to the activation of additional slip planes. Additionally it has been observed that the formability is very sensitive to strain rates. In this paper, experimental and Finite Element (FE) analysis are applied to develop a methodology to determine the forming limits of magnesium alloys AZ31 and WE43 in the deep drawing process using a ductile fracture criterion based on the strain energy density. Based on the developed methodology optimal forming parameters, namely punch radius, temperature, profile radius and forming depth are determined.

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Structures and Buildings Volume 165 Issue SB4Finite-element simulation of a beam to column connection with circle web opening Apostolopoulos, Moraitis and Watiti Connections with pre-cast hollow sections are commonly preferred in recent times because of the convenience they offer. The present work describes a finite-element model developed to simulate the structural behaviour of beam-tocolumn joints with hollow sections. In order to verify the model, a simple beam-to-column joint is modelled in a laboratory test; the joint consists of an end-plate welded to a beam and bolted to a column. The validity of the finite-element model is then established by comparing its results with the corresponding experimental tests.Thereafter a parametric study is carried out to investigate the structural behaviour with variations in the pre-cast web opening radius and distance from the connection.