共查询到20条相似文献,搜索用时 207 毫秒
1.
2.
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
3.
为提高旋压成形数值模拟的计算效率和精度,对偏心管件缩径旋压成形数值模拟网格自适应技术进行了研究。通过有限元数值模拟软件MARC建立了偏心件三旋轮缩径旋压成形的有限元模型;基于MARC软件的UADAPBOX接口,采用箱盒准则,利用二次开发所获得的子程序来控制箱盒区域的运动,实现了成形模拟过程中的网格加密以及加密网格完全可逆等关键技术;对比了采用与未采用自适应技术的等效应变、外层网格扭转、轴向伸长量以及计算效率的变化。结果表明:采用自适应完全可逆技术可以在保证计算精度的前提下,大大缩短了计算时间,提高计算效率近3倍。 相似文献
4.
为探索镁合金整体壁板压弯成形的可行性,以及镁合金壁板压弯成形过程中金属的流动规律,对AZ31镁合金网格壁板压弯成形进行了数值模拟和实验研究。建立了有限元数值模拟的几何模型,采用有限元计算软件对AZ31镁合金网格壁板压弯成形过程进行了数值模拟研究,分析了镁合金网格壁板压弯成形中的温度场、应变场、应力场、破坏系数等的分布规律。确定了合适的AZ31镁合金壁板压弯成形工艺参数,并对镁合金网格壁板压弯成形进行了实验研究,获得了合格的镁合金网格壁板弯曲件,并分析了镁合金网格壁板成形件尺寸精度,模拟结果与实验结果相吻合,最大相对误差为16.7%。 相似文献
5.
6.
为了揭示小弯曲半径高强不锈钢管数控绕弯成形机理,实现精确成形和有效控制的目的,基于ABAQUS有限元平台建立了小弯曲半径21-6-9高强不锈钢管数控绕弯成形全过程三维弹塑性有限元模型;研究了网格尺寸和质量放大因子对有限元模型计算精度和效率的影响,并从理论和实验方面验证了模型的稳定性和可靠性;分析了小弯曲半径高强不锈钢管数控绕弯全过程应力和应变以及对称平面和典型截面上的应力和应变分布的历史演变规律。获取了合理的网格尺寸和质量放大因子分别为0.6×0.6 mm和3000,以及全过程、对称平面和典型截面上的应力和应变分布规律。 相似文献
7.
基于Ansys ls-dyna及Ls-prepost的对同曲率弯管连续二次弯曲进行数值模拟。利用Ansys ls-dy na软件,基于多弯曲模组,实现弯管的二次弯曲。在弯管的成形过程中,观察弯管的成形变化,包括弯管最外侧的减薄率及内侧的增厚率,同时在二次弯曲建模网格划分过程中,采用自适应网格技术,更加贴近实际地反映成形中应力应变的变化。在Ls-prepost中进行后处理,观察管壁减薄率等的变化。弯管的同曲率连续弯曲数值模拟结果有助于工程实际的应用,同时有限元方法有助于促进对弯管弯曲成形的研究。 相似文献
8.
9.
10.
11.
The laser bending of single-crystal silicon sheet (0.2 mm in thickness) was investigated with JK701 Nd:YAG laser. The models were developed to describe the beam characteristics of pulsed laser. In order to simulate the process of laser bending, the FEM software ANSYS was used to predict the heat temperature and stress-strain fields. The periodic transformation of temperature field and stress-strain distribution was analyzed during pulsed laser scanning silicon sheet. The results indicate that the mechanism of pulsed laser bending silicon is a hybrid mechanism in silicon bending, rather than a simple mechanism of TGM or BM. This work also gets silicon sheet bent after scanning 6 times with pulsed laser, and its bending angle is up to 6.5°. The simulation and prediction results reach well agreement with the verifying experiments. 相似文献
12.
激光弯曲工艺中板材厚度的影响规律 总被引:11,自引:0,他引:11
用大变形弹塑性有限元法对金属板材柔性成形新工艺———激光弯曲进行了动态数值模拟。从热学及热力学的观点出发,阐明了该工艺的变形机理,建立了弯曲过程中的应力模型;论证了板料厚度对温度梯度和弯曲角度的影响,提出了能够实现激光弯曲工艺的最小相对光束半径的新概念,为该工艺进一步深入研究奠定了基础。模拟结果与试验吻合较好。 相似文献
13.
WANG Xu-yue XU Wei-xing XU Wen-ji HU Ya-feng LIANG Yan-de WANG Lian-ji Key Laboratory for Precision Non-traditional Machining Technology of the Ministry of Education Dalian University of Technology Dalian China 《中国有色金属学会会刊》2011,(Z1):188-193
The laser bending of single-crystal silicon sheet (0.2 mm in thickness) was investigated with JK701 Nd:YAG laser. The models were developed to describe the beam characteristics of pulsed laser. In order to simulate the process of laser bending, the FEM software ANSYS was used to predict the heat temperature and stress-strain fields. The periodic transformation of temperature field and stress-strain distribution was analyzed during pulsed laser scanning silicon sheet. The results indicate that the mechanism of pulsed laser bending silicon is a hybrid mechanism in silicon bending, rather than a simple mechanism of TGM or BM. This work also gets silicon sheet bent after scanning 6 times with pulsed laser, and its bending angle is up to 6.5o. The simulation and prediction results reach well agreement with the verifying experiments. 相似文献
14.
Francesco Lambiase 《Journal of Materials Engineering and Performance》2012,21(10):2044-2052
In this study, an analytical model is developed to evaluate the bending angle in laser forming of metal sheets. The model is based on the assumption of elastic-bending theory without taking into account plastic deformation during heating and cooling phases. A thermal field is first established, then the thermal component of deformation is calculated and it is used in the strain balance to evaluate the bending angle. The basic idea is that it is possible to use a two-layer model whereas the heated layer thickness depends on the effective temperature distribution along the sheet thickness. A comprehensive experimental study is carried out and the main process parameters, i.e., laser power, scanning speed, sheet thickness, were varied among several levels to evaluate the accuracy of the developed model. Model predictions were confirmed by experimental measurements especially on materials with low conductivity. The established analytical model has demonstrated to provide a great insight into the process parameters effects onto the deformation mechanism within pure temperature gradient mechanism and bucking to temperature gradient transition conditions. 相似文献
15.
16.
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
17.
激光加热弯曲成型技术 总被引:1,自引:0,他引:1
板材激光加热弯曲成形是近年来提出的一种先进的零件成形方法。通过对金属板材激光加热弯曲成型的特点分析,探讨了激光加热弯曲成型的机理,同时对这一技术的发展现状作了归纳并对其发展进行了展望。 相似文献
18.
19.
Sheet metal bending of modern lightweight materials like high-strength low-alloyed steels (HSLA) is one major challenge in metal forming, because conventional methods of predicting failure in numerical simulation, like the forming limit diagram (FLD), can generally not be applied to bending processes. Furthermore, the damage and failure behaviour of HSLA steels are changing as the fracture mechanisms are mainly depending on the microstructure, which is very fine-grained in HSLA steels composed with different alloying elements compared to established mild steels. Especially for high gradients of strain and stress over the sheet thickness, as they occur in small curvature bending processes, other damage models than the FLD have to be utilised. Within this paper a finite element (FE) 3D model of small curvature bending processes is created. The model includes continuum damage mechanics model in order to predict and study occurring failure by means of ductile coherence loss of the material and crack formation with respect to influencing process parameters. Damage parameters are determined by inverse numerical identification method. The FE-model is strain based validated considering the deformation field at the outer bending edge of the specimen by using an optical strain measurement system. The Lemaitre based damage model is calibrated against the experimental results within metallographic analysis adapting the identified damage parameters to the bending process und thus adjusting the crack occurrence in experiment and simulation. Using this model the bendability of common HSLA steel, used for structural components, is evaluated with respect to occurring damage and failure by numerical analysis. 相似文献
20.
Yoshihiro Sagisaka Masayoshi Kamiya Minoru Matsuda Yukihiro Ohta 《Journal of Materials Processing Technology》2010,210(15):2304-2309
A femtosecond laser is a type of ultrashort-pulse laser. Femtosecond laser irradiation induces high-pressure plasma and shock waves at the surface of a target. Under some irradiation conditions, such shock waves are enough to deform the target plastically. Laser peen forming is a type of sheet metal forming using this deformation by shock waves. The author adopted laser peen forming using femtosecond laser for thin-sheet-metal bending. Generally, shock waves induced in air are much smaller than those induced in water, and thus; are unfavorable for plastic deformation. However, the shock waves induced by a femtosecond laser were enough to bend a thin sheet metal even in air. Elastic pre-bending was adopted during the process. Bending angle was increased by applying pre-bending. The effects of laser irradiation conditions on bending efficiency were investigated. The large spot diameter and high fluence improved bending efficiency. 相似文献