Papers by Keyword: Metal Plates

Abstract: Numerical simulations with ABAQUS/Explicit into which Johnson-Cook constitutive relation is incorporated, are performed to study the perforation of Weldox 460E steel plates struck normally by conical-nosed projectiles with different cone angles. Different failure modes and perforation process are obtained. Numerical results are found to be in good agreement with available test data. It is revealed that with increasing cone angle, the failure modes of metal plates become to shear plugging from ductile hole enlargement, and the ballistic limits decrease with that. The conclusions are helpful for the design of protective structures.

Abstract: PLC (programmable logic controller) is one type of general industrial control platforms. Based on the PLC of SIMENS S7-200 series, this paper introduces a control scheme of cutting metal plates control system in the flame cutting machine. The hardware design and PLC program are given in details, which achieve accurate position and fixed-length cutting by the stepper motor through the control of PLC. In addition, the configuration simulation of the system is performed by the application of King view software. The control system has multiple operating modes, high reliability, stability and is able to meet the variety of different work requirements. The automatic control of cutting metal plates is achieved. The control system is applied to actual projects and can greatly enhance productivity.

Abstract: The principle of laser peen forming (LPF) is introduced, the loading model of laser shock wave is established. This paper focuses on applying finite element analyses, instead of a complicated experimental procedure, to predict the development, magnitude and distribution of residual stresses induced by laser impacts on a metal plate, and dynamic process of laser continuous peen forming is realized with the FEM code ABAQUS. Based on the numerical analysis, the laser processing parameters can be optimized and the deformation contour of metal plate can be analyzed. The results calculated by the finite element method are correlated well with the available experimental results. The simulated results also reveal that adjusting the laser energy appropriately can result in an anticipated shape of plate in LPF process.

Abstract: The laser peen forming (LPF) uses high-power pulsed laser beam replacing the tiny medium balls to peen the surface of plate and generate compressive stress near the surface, the metals respond to this residual stresses by elongating at the peened surface and effectively bend the overall shape. In this paper, the deforming process of metal plate induced by repetitive pulsed laser was discussed from theory firstly, and the bending mechanism of LPF was investigated. Then a mathematical model of bending curvature concerning the depth of residual stress was presented, the influence of residual stresses on the deformation of plate was analyzed. Lastly, the line-track-peening experiment for SUS 304 plate was carried out to evaluate the reasonability of the theoretical analysis model.

Abstract: In the current world of engineering, structural vibration problems continue impact the design and construction of a wide range of products. Amid the parameters that determine the dynamic behaviour of a structure the one that takes into account the dissipation of energy resulting in the decay of the vibration is the least understood and the most difficult to quantify [1]. The estimation of damping factors is of interest in most branches of engineering sciences. In the field of aircraft structures the damping directly affects the fatigue life, a parameter which is applied conservatively due to the inherent complexity in modelling the damping of built up structures and the potentially catastrophic consequences of a fatigue failure. One of the most important problems is the limited knowledge of how joints affect the damping of the complete structure. This work therefore addresses this issue and focuses on the damping of joints in metal plates as part of a larger project to investigate the damping of built up structures. Various plate configurations are experimentally investigated using two different approaches. The results from the configurations are compared and discussed along with the advantages and disadvantages of each experimental approach. This enables a link to be identified between the damping magnitudes and the mode shapes and joint stiffnesses.