共查询到17条相似文献,搜索用时 125 毫秒
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《塑性工程学报》2018,(6)
为了分析激光弯曲成形过程中各个工艺参数对弯曲角度的影响,从而对弯曲角度进行预测,在激光弯曲成形过程中对激光功率、光斑大小、扫描速度、扫描次数、线能量密度等参数进行了合理控制,根据实验结果分析了各个工艺参量对弯曲角度的影响,并基于最小二乘法对激光弯曲角度进行了预测。结果表明当光斑大小和扫描速率等工艺参数恒定时,工件的形变角度随功率增大而逐渐增大,弯曲角度随扫描速率的增加呈先增后减的凸函数曲线形状;弯曲角度与扫描次数近似呈线性关系;弯曲角度随线能量密度增大先增大后减小。若激光弯曲后工件能够得到充分冷却,则每次扫描引起的角度增量基本相等。本实验条件下,线能量密度取6. 7 J·mm-2时可在多次加工后获得最大弯曲角度。 相似文献
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为了探究汽车车身用DP980双相高强钢板的激光弯曲成形特性以及激光参数对弯曲角的影响,利用ABAQUS有限元分析软件对DP980双相高强钢板的激光弯曲成形过程进行了数值模拟,研究了激光扫描过程中板材内部的温度场分布,揭示了DP980钢板激光弯曲成形的机理;并对激光功率、扫描速度、线能量等激光参数对板材弯曲角的影响进行了分析。结果表明,DP980双相高强度钢板的弯曲角随着激光功率的增加而增加,随着扫描速度的增加而减小,在一定的线能量范围内,弯曲角大小与线能量呈线性增长关系,并推导出了用于预测钢板弯曲角的数学模型。 相似文献
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中厚船舶钢板激光弯曲成形几何效应的数值模拟 总被引:2,自引:0,他引:2
建立板材激光弯曲的三维非线性准静态弹塑性热力耦合有限元模型。使用有限元软件 MSC Marc对中厚船舶钢板的激光弯曲成形过程进行数值模拟。计算了船舶钢板激光弯曲成形过程的温度场和变形场, 并进行相应的实验验证。模拟结果与实验结果吻合较好。用建立的模型对中厚船舶钢板的激光弯曲成形过程中钢板的几何效应进行数值模拟, 讨论了一定工艺条件下钢板几何参数与弯曲角度之间的关系, 为在将来实际生产中制定和优化钢板激光弯曲成形的工艺参数提供理论依据。 相似文献
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激光参数对Ti6Al4V钛合金激光冲击成形的影响 总被引:1,自引:1,他引:1
研究在Ti6Al4V合金激光冲击成形过程中,不同激光参数对板料弯曲角及表层硬度的影响。结果表明:当激光功率密度小于3GW/cm2时,弯曲角随着激光功率密度线性增加,激光功率密度超过3GW/cm2时,由于表面熔化现象的出现,弯曲角出现减小的趋势;板料弯曲角随冲击次数的增加也呈线性增长,但弯曲阻力的增加使得弯曲角的增长速度逐渐减慢;随着激光功率密度的增加,材料表面冲击区的硬度增高,表面硬化层的显微硬度最高达HV490,硬化层厚度约为1.0mm。 相似文献
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Z. Hu M. Labudovic H. Wang R. Kovacevic 《International Journal of Machine Tools and Manufacture》2001,41(4)
Computer simulation and experimental investigation of the sheet metal bending into a V-shape by the laser beam scanning without an external force exerted onto it have been performed. A 3-D FEM simulation has been carried out, which includes a non-linear transient indirect coupled thermal-structural analysis accounting for the temperature dependency of the thermal and mechanical properties of the materials. The bending angle, distribution of stress–strain, temperature and residual stresses have been obtained from the simulations. The sheet metal bending had been performed for different materials, thicknesses, scanning speeds and laser powers. The measurement of real-time temperature and bending angle was carried out. The bending angle is affected by the mechanical and thermal properties of the sheet metal material, the process parameters, and the output of laser energy. The bending angle is increased with the number of laser beam scanning passes and is the function of the laser power and the laser beam scanning speed. The simulation results are in agreement with the experimental results. 相似文献
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Yanjin Guan Hongmei ZhangJie Liu Shen Sun 《Journal of Materials Processing Technology》2012,212(3):662-671
The laser polarization is a basic characteristic of CO2 and solid-state lasers. The material's absorptivity to laser is dependent upon the laser incident angle. Thus, the laser polarization can be utilized to control the bending angle by changing the laser incident angle during laser bending. The laser polarization is introduced into laser micro-bending, and an experimental system is established. Laser micro-bending process based on the characteristic of the laser polarization is realized. For uncoated stainless steel specimen, the bending angles acquired at bigger incident angles are bigger than those acquired at zero incident angles. The bending angles increase linearly with the increase of the incident angle when the incident angle changes from 60° to 80°. During laser multi-scan bending, the final bending angle no longer varies with the scanning number, and approximately equals to the complement angle of the incident angle when it approaches to the complement angle. By means of adjusting the laser incident angle and scanning velocity, unfinished and finishing laser bending can be realized to satisfy the forming efficiency and accuracy. The absolute error between the final bending angle and the expected angle is less than 0.1°. 相似文献
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NUMERICAL INVESTIGATION OF STRAIGHT-LINE LASER FORMING UNDER THE TEMPERATURE GRADIENT MECHANISM 总被引:1,自引:0,他引:1
Y.J. Shi H. Shen Z.Q. Yao J. Hu 《金属学报(英文版)》2006,19(2):144-150
Laser forraing is a new flexible and dieless forming technique. To achieve the high accuracy forming, the temperature gradient mechanism (TGM) is studied. In the analysis of TGM, the plate bends about x-axis and about y-axis as well. To understand the deformation trend, the numerical simulation of deformation of plate is conducted by choosing different laser powers, laser spot diameters, scanning speeds, lengths, widths and thicknesses. From the results of simulation, it can be seen that the laser spot diameter, the scanning speed, laser power and thickness of plate play dominant roles in the laser forming process. However, the bending angles αx and αy show different trends with the variation of parameters. In addition, in comparison with above four parameters, the effect of length and width of plate on the beading angle may be neglected, but their effects are significant for the bending radius R. 相似文献
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在综合分析材料热物理性能和力学性能的基础上,建立了板料激光弯曲成形的三维热力耦合模型。利用有限元分析软件对1Cr17Ni2不锈钢板的激光单次扫描弯曲过程进行了数值模拟,得到了应力一应变场模拟结果。模拟结果表明,当高能激光束沿板料表面扫描,在板厚方向会产生强烈的温度梯度,致使加热区材料的塑性应变沿板厚方向差别很大,从而导致板料的弯曲变形。 相似文献
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J. Lawrence M. J. J. Schmidt L. Li 《International Journal of Machine Tools and Manufacture》2001,41(7)
Bending of 07 M20 mild steel sheets to various degrees using a contemporary 2.5 kW high power diode laser (HPDL) has been successfully demonstrated for the first time. The experimental results revealed that the HPDL induced bending angle increased with an increasing number of irradiations and high laser powers, yet decreased as the traverse speed was increased. It was also apparent from the experimental results that the laser bending angle was only linearly proportional to the number of irradiations when the latter was small. It is believed that the absence of linearity observed when the number of irradiations was high is due to local material thickening along the bend edge. From graphical results and the employment of an analytical model, the laser line energy range in which accurate control of the HPDL bending of the 07 M20 mild steel sheets could be exercised was found to be between 138 and 260 J/mm−1. 相似文献
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以Q235钢为基板,采用IPGYLS-4000型光纤激光器以及旁轴送粉器,搭建旁轴同步送粉式激光扫描熔覆工艺试验平台,在基板上进行熔覆试验。研究了激光功率、扫描速度和扫描宽度对熔覆层成形尺寸和对熔覆层组织的影响,结果表明:随着激光功率增大,铁基合金粉末熔化量提高,单层金属熔覆层的余高增加;扫描速度对熔覆层熔宽和余高的影响均较大,随着扫描速度的降低,金属熔覆层熔宽余高均增加,裂纹数量增多。约束应力是导致熔覆层出现裂纹的主要原因,通过优选工艺参数可以获得工艺良好无裂纹熔覆层,为下一步研究激光扫描多层熔覆无(小)变形焊接技术提供理论和技术依据。 相似文献
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目的获得制备形貌较佳的CBN激光熔覆层的工艺参数。方法以CBN粉末为熔覆材料,在TC11钛合金表面制备CBN熔覆层。设计正交试验,利用金相法检测熔覆层的几何形貌参数,研究工艺参数(激光功率、扫描速度、离焦量、预置层厚度)对涂层几何形貌的影响规律。结果随着激光功率、扫描速度、离焦量和预置层厚度的增大,熔覆层宽度、高度以及熔池深度都发生相应的改变。其中扫描速度对熔覆层形貌的影响最大,其次为激光功率和预置层厚度,离焦量的影响最小。随着激光功率增大,熔覆层宽度先增大后减小,熔覆层高度逐渐降低,熔池深度逐渐增大。扫描速度、离焦量和预置层厚度的增加都导致熔覆层宽高和熔池深度的减小。结论最优的工艺参数为:激光功率1400W,扫描速度4mm/s,离焦量35mm,预置层厚度0.4mm。 相似文献