The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform
J Duszczyk - One of the best experts on this subject based on the ideXlab platform.
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3d fem simulation of the whole cycle of aluminium extrusion throughout the transient state and the steady state using the updated lagrangian approach
Journal of Materials Processing Technology, 2003Co-Authors: J Zhou, J DuszczykAbstract:Abstract Aluminium extrusion involves the generation of free surface, thermal effects, large deformations and complex geometries. The established finite element method (FEM)-based 3D simulation tools using the updated Lagrangian approach, or the Eulerian approach or the arbitrary Lagrangian Eulerian approach all have limitations in describing the process that develops from the transient state to the steady state before reaching the end when the steady state is disturbed. As a result, the simulation of aluminium extrusion performed so far has been restricted to simple geometries, small length-to-diameter (L/D) ratios, the beginning stage or steady-state conditions. This paper reports on an unprecedented attempt to simulate an entire cycle of aluminium extrusion from a billet with an L/D ratio of 4 to a solid cross-shaped profile, using the DEFORM 3D software based on the updated Lagrangian approach. Simulation successfully predicts a complete extrusion pressure/ram displacement diagram that begins with a pressure breakthrough and ends with another pressure rise due to the inhibition of metal flow by the rigid Dummy Block. The developments of velocity, effective strain and temperature inside the deforming billet indicate that the process is non-steady, even in the steady state, as a result of continuous heat generation and sticking condition at the billet–container interface. The non-steady characteristics are reflected in the expanding deformation zone and shrinking dead metal zone. Simulation also reveals the patterns of the maximum temperature variations in the workpiece and in the tooling, due to heat generation and exchange. Even at a relatively low ram speed of 2 mm/s, the maximum temperature of the workpiece, after an initial steep rise, increases gradually till the end of the process, which may well lead to the occurrence of hot shortness. On the basis of these results, a change of the conventional mode of aluminium extrusion is recommended, which at present operates almost all at a constant ram speed and often begins with a uniform billet temperature across the aluminium extrusion industry in the world.
J Zhou - One of the best experts on this subject based on the ideXlab platform.
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3d fem simulation of the whole cycle of aluminium extrusion throughout the transient state and the steady state using the updated lagrangian approach
Journal of Materials Processing Technology, 2003Co-Authors: J Zhou, J DuszczykAbstract:Abstract Aluminium extrusion involves the generation of free surface, thermal effects, large deformations and complex geometries. The established finite element method (FEM)-based 3D simulation tools using the updated Lagrangian approach, or the Eulerian approach or the arbitrary Lagrangian Eulerian approach all have limitations in describing the process that develops from the transient state to the steady state before reaching the end when the steady state is disturbed. As a result, the simulation of aluminium extrusion performed so far has been restricted to simple geometries, small length-to-diameter (L/D) ratios, the beginning stage or steady-state conditions. This paper reports on an unprecedented attempt to simulate an entire cycle of aluminium extrusion from a billet with an L/D ratio of 4 to a solid cross-shaped profile, using the DEFORM 3D software based on the updated Lagrangian approach. Simulation successfully predicts a complete extrusion pressure/ram displacement diagram that begins with a pressure breakthrough and ends with another pressure rise due to the inhibition of metal flow by the rigid Dummy Block. The developments of velocity, effective strain and temperature inside the deforming billet indicate that the process is non-steady, even in the steady state, as a result of continuous heat generation and sticking condition at the billet–container interface. The non-steady characteristics are reflected in the expanding deformation zone and shrinking dead metal zone. Simulation also reveals the patterns of the maximum temperature variations in the workpiece and in the tooling, due to heat generation and exchange. Even at a relatively low ram speed of 2 mm/s, the maximum temperature of the workpiece, after an initial steep rise, increases gradually till the end of the process, which may well lead to the occurrence of hot shortness. On the basis of these results, a change of the conventional mode of aluminium extrusion is recommended, which at present operates almost all at a constant ram speed and often begins with a uniform billet temperature across the aluminium extrusion industry in the world.
Tan Jianping - One of the best experts on this subject based on the ideXlab platform.
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design and application in 125mn extrusion press Dummy Block transportation system of the variable frequency speed regulation system
Modern Manufacturing Engineering, 2009Co-Authors: Tan JianpingAbstract:Combined with technical transformation of 125MN extrusion press extrusion Dummy Block transportation system,by analyzing the existing problem in the old system,choose a scientific project-to make a frequency-converter speeding-adjusting system of crane based on communication of Profibus-DP.This system has reduced trouble times and improved circulate speed and control accuracy besides,credible experience is provided for other equipment alteration.
Han Hon - One of the best experts on this subject based on the ideXlab platform.
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automatic control of Dummy Block transport manipulator of aluminum extrusion press
Forging and Stamping Technology, 2013Co-Authors: Han HonAbstract:The method of Dummy Block transport is a key technology of double aluminium extrusion press which uses running Dummy Block usually.According to extrusion characteristics of the Dummy Block for transport,the Dummy Block transport manipulator was designed,the original transport mode of lifting-translation-reverse was promoted,the new transport mode of translation-ratation was taken,and the automatic control system was designed and developed independently.The practice proves that the reliable and stable operation of manipulator is got,the position control accuracy is improved,the activity of the gasket automatic circulation is realized,the double non-extrusion of aluminium extrusion press time is reduced and the double aluminium extrusion machine productivity is effectively improved.
W U Kaikai - One of the best experts on this subject based on the ideXlab platform.
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thermal structure analysis on fixed Dummy Block of 55 mn aluminum extrusion press
Forging and Stamping Technology, 2011Co-Authors: W U KaikaiAbstract:The fixed Dummy Block bears high temperature,high pressure,and friction under complex working condition.The three dimensional finite element analysis model of fixed Dummy Block of 55 MN aluminum extrusion press was established using finite element software MSC.Marc,which includes pad Block,outer jacket,and fastening pad Block as deformation contact body,and considering temperature effect,the thermal-structure analysis was carried out using direct coupling method.It indicates that working surface node radial expansion of the outer jacket is gradually incremental with successive working load,and has three different increase intervals of rapid,slow and steady rate.These conclusions provide a reference for optimal design of fixed Dummy Block.
