共查询到17条相似文献,搜索用时 187 毫秒
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电磁成形中板料厚度与变形深度的关系 总被引:2,自引:0,他引:2
通过纯铝板的电磁胀形试验,发现在工艺条件相同的情况下,不同厚度的板料有不同的变形深度,而且在试验条件下,对于性能相同的材料,厚板的变形深度比薄板的要大。对这一现象进行了分析,认为这是由于不同的板料厚度可以导致不同的设备能量利用率,而其最根本的原因则是趋肤效应。在设备能量相同的情况下,若板料厚度小于趋肤深度,则板料的厚度越大,变形深度越大;板料厚度大于趋肤深度时,板料厚度越大,变形深度越小。并且分析了如何能获得一个最高的设备能量利用率,得出了设备电容与放电回路电感之间的关系。研究成果对指导电磁成形的工艺设计有着重要的意义。 相似文献
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钛合金板料激光冲击变形的数值模拟和实验 总被引:3,自引:0,他引:3
实验研究了激光能量和不同的冲击路径、冲击次数对TA2钛合金板料变形的影响,并用ABAQUS软件进行了有限元模拟。结果表明:随着激光能量的增加,板料的变形量增大;板料几何尺寸和厚度越大,板料越难变形;冲击次序不同,板的变形量也不同,板的变形以沿板的长度方向且对称冲击为最大。通过数值模拟可优化激光冲击的相关参数,预测板料变形。 相似文献
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在数控加工前,必须根据工件的形状、尺寸精度等将工件各关键点坐标的位置准确无误地确定在平面上,通过分析这些点的坐标尺寸及相互关系,并用机床所能接受的指令编制出程序,作为信息输入机床,使其加工工件。但有大量工件,其尺寸精度要求高,形状复杂,APT编程时,在XOY平面上难以确定出关键点的位置,需借助大量的辅助点进行辅助运算,这样计算出的关键点坐标就会产生取舍误差,不仅编程时间长,也影响工件的加工精度,甚至会造成工件报废。在这种情况下,若采用极坐标法,则只需确定关键点的一个极半径ρ和极角θ两参数,而且在编… 相似文献
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Quanliang Cao Liang Li Zhipeng Lai Zhongyu Zhou Qi Xiong Xiao Zhang Xiaotao Han 《The International Journal of Advanced Manufacturing Technology》2014,74(1-4):361-368
This paper presents a simple and efficient method for the analysis of dynamic behavior of the workpiece in the electromagnetic forming process. A two-dimensional (2D) axisymmetric finite element model with the equations of electrical equivalent circuit, electromagnetic field, and mechanical field has been developed for calculating the discharge currents through the forming coil, the magnetic forces acting on the workpiece, and the plastic deformation of the workpiece. By considering the effects of the sheet geometry and velocity on the above parameters, the method realizes the full coupling between the electromagnetic fields and the workpiece deformation, which should be more accurate than the existing loose coupling and sequential coupling simulation methods. 相似文献
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Fenqiang Li Jianhua Mo Jianjun Li Haiyang Zhou Liang Huang 《The International Journal of Advanced Manufacturing Technology》2013,69(1-4):127-137
In order to improve energy efficiency, a driver plate made from high-conductivity material is normally used in the electromagnetic forming process of high-strength but low-conductivity sheet metal. The choice of driver plate significantly influences final deformation of the workpiece. In this paper, the electromagnetic free bulging process of Ti-6Al-4V titanium alloy sheet, widely used in aerospace, was studied by both experimental means and numerical simulation. The forming efficiency and quality of the workpiece under different types of driver plates were investigated in detail. The results show that by using high-conductivity and easily deformed materials such as aluminum alloy, with a skin depth in thickness, high efficiency and uniform deformation can be achieved. The results of this study can provide guidance on the choice of process parameters such as the material and thickness of a driver plate. 相似文献
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激光冲击金属板料变形的 最小激光能量估算及其实验研究 总被引:3,自引:7,他引:3
介绍了激光冲击板料变形的机理和冲击波产生的原因,提出了激光冲击板料变形中激光-能量转换体-靶材系统的爆轰波压力估算式。根据此压力估算式和材料的动态屈服强度,对激光冲击板料变形中所需的最小激光能量进行了估算,板料厚度为0.5 mm,约束凹模孔径Φ20 mm,在光斑直径6 mm,脉宽25 ns条件下的不锈钢靶材变形所需的最低脉冲能量大约为11 J。实验结果表明估算的最小激光能量与板料变形所需的能量阈值基本一致,且板料变形量随激光能量的增加呈非线性增大。最小激光能量的估算以及能量与板料变形的实验研究为板料变形的精确控制和预测提供了理论依据。 相似文献
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为了更高效地清洗圆柱形金属工件内表面,设计了此套毛刷清洗设备。毛刷清洗机主要执行元件有加热电阻、电磁阀、气缸和三相交流电动机。该电气控制系统以三菱FX2N系列PLC为核心控制器,通过对线圈和电磁阀的控制,能够方便地实现毛刷电机的转动、清洗篮的上下摆动、储液箱的循环加热以及清洗液的排放,从而完成对金属工件内表面的清洗。该设备投入使用后,表现出工作性能稳定、操作方便、经济适用等优点,能够很好地完成对金属工件的清洗工作。 相似文献
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J.P.M. Correia M.A. Siddiqui S. Ahzi S. Belouettar R. Davies 《International Journal of Mechanical Sciences》2008,50(10-11):1466-1475
Electromagnetic sheet forming is a high-velocity forming process driven by the coupled electromagnetic and mechanical phenomena. The deformation of the workpiece is governed by the body forces (Lorentz forces) that results from a pulsed magnetic field produced by a flat spiral coil. Formability can be increased using this high-velocity forming technique due to the inertial forces and high strain rates. In this study, we consider the electromagnetic and the mechanical aspect of the process as two independent problems. The finite difference method has been employed to solve the electromagnetic equations. The pressure acting on the sheet and due to the Lorentz forces is estimated neglecting the influence of the sheet velocity on the magnetic field. Then it has been treated as a load in the mechanical problem. Numerical simulations of the mechanical problem have been performed with the commercial finite element code ABAQUS/Explicit. The magnetic pressure has been introduced in ABAQUS/Explicit as an analytical pressure distribution. The general objective of this study is to better understand the complex phenomenon of deformation and the influence of viscoplastic material behaviour during the simulation of a free bulging electromagnetic sheet forming process. 相似文献
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Hak-Gon Noh Woo-Jin Song Beom-Soo Kang Jeong Kim 《Journal of Mechanical Science and Technology》2014,28(8):3263-3271
Electromagnetic forming (EMF) is a high strain rate forming process that uses Lorentz force. In this study, electromagnetic forming with a rectangular block shape in the center of the forming die was examined to determine the possibility and applicability of EMF. However, the high speed of the process in the absence of a medium between the coil and the workpiece results in bouncing of the workpiece, which may result in poor forming. So, in this study, the use of a cushion plate is proposed as a means of reducing the degree of bounce in an EMF process. A 3D electromagnetic numerical model using a spiral forming coil was considered. An RLC circuit, coupled with the spiral coil, was numerically simulated to determine the deformation behavior and design parameters, such as the input current and the magnetic forces. A cushion plate was used between the forming coil and the sheet to be deformed to reduce the extent of bounce. In the numerical simulation, the sheet was found to be well fitted to the objective die with the cushion plate. The simulation results showed that the extent of bounce was drastically reduced because of the velocity direction of the workpiece and the cushion plate. The experiment was performed using 24 kJ to deform Al 1100 with a thickness of 1.27 mm, based on the simulation results. The deformed sheet was well formed, and closely fitted the objective die with a minimum of wrinkling, relative to the results obtained without a cushion plate. As a result, an EMF process with a middle-block die was successfully established both numerically and experimentally to reduce the bouncing. 相似文献
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Shih-Bin Wang Chih-Fu Wu 《The International Journal of Advanced Manufacturing Technology》2006,28(1-2):31-37
In this study, the grinding force of the creep feed grinding are modeled and forecasted by using the improved back propagation
neural (BPN) network. The results show that the grinding energy can be accurately predicted by the application of the grinding
force model. Due to the previous paper, the workpiece burning occurs as the grinding energy is greater than the critical grinding.
Thus, a judgment for the occurrence of the workpiece burning can be achieved. Comparing with the experimental results, the
applied algorithm of the improved BPN network is proved to be effective in forecasting the working conditions of the workpiece
burning. Thus, a selection scheme of working conditions in view of the avoidance of the workpiece burning is further developed.
Considering the working efficiency, the working conditions are selected to maximum metal removed rate, MRRmax. The results show that a larger size of wheel is available to have a better working efficiency. 相似文献