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1.
板料激光弯曲成形工艺参数优化设计   总被引:1,自引:1,他引:0  
提出了一种以动态显式有限元为解算器,并采用遗传算法对矩形板激光弯曲成形工艺参数进行优化设计的方法。介绍了根据拟成形角度,制定板料激光弯曲成形工艺参数的过程,并通过一算例公布了一组优化的工艺参数。  相似文献   

2.
基于人工神经网络的板料激光成形工艺优化   总被引:1,自引:0,他引:1  
刘韧  王忠雷  季忠 《锻压技术》2005,30(1):26-29
采用BP算法的人工神经网络系统,以激光能量、光斑大小、扫描速度、矩形板料的厚度和宽度作为输入层节点,预测板料激光成形的温度峰值和弯曲角度,并将该系统用于08F薄钢板激光弯曲成形的工艺参数优化之中,可以快速获得最大成形角度所对应的最优工艺参数组合。  相似文献   

3.
针对超高强钢难成形的问题,提出了激光辅助机器人双点滚压成形工艺。以弯曲为例,研究了激光功率密度对弯曲零件回弹的影响,并基于响应曲面法,以回弹角度为目标函数,成形载荷为约束条件优化了角度增量和工业机器人位移补偿参数。结果表明,超高强钢零件回弹角度随着激光功率密度的增大而减小,激光功率密度为125 W·mm-2时零件回弹角度相较于常温成形减小了78.5%,但回弹减小趋势随着激光功率密度继续增大趋于平缓;将激光功率密度固定为125 W·mm-2,进一步通过响应曲面法将成形过程载荷控制在600~900 N范围内,得到了优化的4道次角度增量和两滚轮位移补偿值,相较于优化前的4道次成形策略,弯曲零件的回弹角度从6.0°降低到接近于0°。响应曲面法可用于优化机器人双点滚压成形工艺参数,从而显著降低滚压成形零件的回弹并且提高成形效率。  相似文献   

4.
基于遗传算法的板料激光弯曲成形工艺优化设计   总被引:7,自引:3,他引:4  
遗传算法是一种全局优化方法,它较之其他经典的优化方法的优点是不会陷于局部最优,而且能够处理大规模优化问题,因此,更适合于工程分析及应用。文中将激光弯曲成形过程分为粗加工及精加工阶段,并应用遗传算法与动态显式有限元相结合,采用分步优化的方法对其工艺参数进行了优化设计,并通过一个实例公布了一组优化结果。  相似文献   

5.
金属板材激光弯曲成形应力应变场的数值模拟   总被引:1,自引:0,他引:1  
采用有限元对激光弯曲成形过程中应力应变场的过程进行了模拟,分析了弯曲成形过程中钢板上下表面弹塑性变形的变化规律及激光工艺参数对成形的影响。模拟结果与实验结果基本一致。  相似文献   

6.
激光诱发热应力成形试验研究   总被引:1,自引:0,他引:1  
利用2kW CO2激光器研究了低碳钢板料的激光弯曲情况,试验结果表明,对于多道扫描激光成形工艺,弯曲角度受到许多工艺参数的影响。其中,激光功率、光束直径、扫描速度、扫描次数、板料厚度等参数的效应尤其显著。对试验结果的定性分析,所得的结论可为激光弯曲成形技术的进一步理论研究和可能的工业应用提供依据。  相似文献   

7.
船舶钢板激光弯曲成形的实验研究   总被引:6,自引:0,他引:6  
在对船舶钢板激光弯曲成形过程进行实验研究中,采用CO2激光器研究了激光功率、扫描速度、扫描次数以及钢板厚度对船舶钢板激光弯曲成形的影响规律。实验中实时测量了船舶钢板激光弯曲成形过程钢板弯曲角度和温度的变化。结果表明:钢板弯曲角度随激光功率的增加而增加,随激光束扫描速度的增加而减小,而且随着钢板厚度的增加,弯曲角度减小;激光工艺参数和钢板厚度都对钢板激光多次扫描成形产生影响,钢板的弯曲角度随着激光扫描次数的增加而增加。对于较薄的船舶钢板,钢板弯曲角度随扫描次数增加近似呈线性增加,而较厚的钢板,随扫描次数的增加,钢板弯曲角度的增加逐渐减小。  相似文献   

8.
渐进式板料激光三维成形及工艺优化   总被引:1,自引:0,他引:1  
将板料的激光三维成形视为V形激光弯曲成形的复合 ,分析了曲面筒形件与V形弯曲件的几何相关性 ,建立了用点坐标表示的弧面曲率表达式。以工件的曲率半径为优化目标 ,有限元软件包ls dyna3D作为目标函数解算器 ,并结合遗传算法 ,求出了优化的工艺参数及其各成形瞬时的位移场 ,并与实验进行了对照  相似文献   

9.
激光成形工艺方法及其发展前景   总被引:4,自引:0,他引:4  
介绍了激光成形的工艺特点和四种不同的工艺方法:板材正向弯曲,板材反向弯曲,型材弯曲、空间变形。分别阐述了这四种工艺的成形机理和可能的应用领域,以及激光成形的发展前景。  相似文献   

10.
以汽车离合器波形弹簧片作为分析对象,利用响应曲面法对冲压成形工艺参数进行优化。通过中心设计组合法及弯曲成形模具得出板料成形高度的响应值,建立了工艺参数与成形高度之间的二阶响应面模型,研究得知工艺参数对板料成形高度交互式影响的顺序依次为:弯曲半径与冲压速度、模具间隙与冲压速度、弯曲半径与模具间隙。将模具间隙、弯曲半径以及冲压速度作为设计变量,以板料成形高度作为优化目标,结合Design Expert软件对响应曲面模型进行优化,通过分析得出优化的冲压工艺参数:弯曲半径为22.13 mm,模具间隙为1.01t mm,冲压速度为2699.47 mm·s-1,成形高度的响应值为1.782 mm,经过工艺参数的修正,成形高度的试验值为1.72 mm。然而相比于正交试验得出的成形高度优化值1.65 mm,响应曲面法在波形弹簧片冲压成形工艺参数的优化中更具优越性。  相似文献   

11.
In resistance spot welding of thin sheet–thick sheet–thick sheet joint, when the sheet thickness ratio is large (sheet thickness ratio = total thickness of sheet joint/thickness of the thin sheet positioned on the outside of the joint), how to stably secure the nugget between the thin sheet and the adjoining thick sheet is a key issue. If the sheet thickness ratio is so large, nugget formation between the thin sheet and thick sheet is extremely difficult. In order to control of the nugget (position of formation, shape, etc. of the nugget) during welding for three sheets joint with a high sheet thickness ratio, optimum welding process was investigated. The developed ‘two-step force, two-step current’ welding process was suitable for high sheet thickness ratio joint and relaxed the constraints on the sheet thickness ratio. In Step 1 (first part of welding period) of the welding process, a nugget is reliably formed between the thin sheet and thick sheet by applying conditions of low electrode force, short welding time, and high current. In the subsequent Step 2 (second part of welding period), a nugget is formed between the two thick sheets by applying high welding force and a long welding time. In the weld results of a three sheet joint (0.7+2.3+2.3 mm; sheet thickness ratio: 7.6) using mild steel GA (0.7 mm) as the thin sheet and 780 MPa high strength GA (2.3 mm) in the two thick sheets, ‘two-step force, two-step current’ spot welding process showed the wide available welding current range.  相似文献   

12.
A combination of complex surface capacitance mapping and sheet resistance mapping is applied to establish the origin of resistance variations on semi-insulating (SI) 6H–SiC substrates. The direct correlation between the capacitance quadrature and the sheet resistance is found in vanadium-doped SI samples. Regions with low capacitance quadrature show high sheet resistance. This indicates, associated with the nonhomogeneity of sheet resistance on the substrate, that the quality of crystallization is not good enough, which also leads to resistivity nonhomogeneity when comparing with different types of deep defects. According to the capacitance mapping, the region with bad crystallization quality has a high radio absorption coefficient. Another correlation is established between the capacitance in-phase and sheet resistance for the vanadium-doped sample. In this sample, the capacitance in-phase map shows not only the surface topography, but also the same distribution trend as the sheet resistance, namely, regions of high capacitance in-phase reveal high sheet resistance.  相似文献   

13.
M. Shiomi  K. Osakada 《CIRP Annals》2006,55(1):255-258
In order to improve the dimensional accuracy of the hole made by piercing a sheet/tube in hydroforming, some piercing methods using hydrostatic pressure are examined. In piercing by pushing a steel sheet into the pressurised liquid with a punch, the sheet is warped and the edge of the hole sinks (edge drop). In piercing by pushing the sheet outwards with hydrostatic pressure while the punch recedes, warping is suppressed but burr is formed. When the sheet is first pushed with the punch into the liquid and then piercing is completed by receding of the punch, burr is not formed and edge drop decreases by about 50%.  相似文献   

14.
夹层钢板冲压的成形机理与缺陷分析   总被引:1,自引:0,他引:1  
介绍了夹层钢板的材料结构、夹层钢板的冲压成形性及在成形过程中容易产生的缺陷,总结了影响夹层钢板成形性能的因素。介绍了夹层钢板在汽车行业中的应用情况及国内外的研究现状,并指出了当前车用夹层钢板研究的热点难点,对夹层钢板在此行业中应用发展做了展望。  相似文献   

15.
采用热力耦合有限元数值模拟方法对铝合金圆锥形零件粘性介质温成形过程进行了模拟分析,研究了成形过程粘性介质和板材的温度分布、不同温度条件下成形零件壁厚分布、成形载荷等.结果表明,圆锥形零件的底部圆角区域为成形危险区域.非等温粘性介质温成形过程中,在粘性介质内部形成的非均匀温度场影响了板材的温度分布.当粘性介质温度略低于板材温度时,坯料中心区域温度较低,有利于延迟底部圆角成形时的破裂,提高了零件壁厚的均匀性.分别进行了室温和加热时铝合金圆锥形零件粘性介质压力成形试验,试验结果与数值模拟具有相同的规律.  相似文献   

16.
Electromagnetic field is an available online method to increase bonding strength of clad sheet manufactured by horizontal twin-roll casting(HTRC). In this paper, an electric current pulse(ECP) and a complex field(static magnetic field(SMF) together with ECP) are exerted during HTRC of steel/aluminum clad sheet. The produced clad sheet has good appearance, and no visible defects exist at the bonding interface. The inter-diffusion zone at Fe/Al interface in ECP and SMF+ECP sheets is 3 and 4 lm, respectively, and the latter increases slightly compared with that in non-field sheet. The average peel strengths(APS) of ECP and SMF+ECP sheet are 14 and 21 N/mm, respectively, which increase by 2 and9 N/mm compared with 12 N/mm of non-field sheet. The APS increment in SMF+ECP sheet is resulted from the increment of interface bonding spots and the enhancement of inter-diffusion zone width.  相似文献   

17.
CSP卷取温度对冷轧深冲钢板的影响   总被引:1,自引:0,他引:1  
研究了热轧卷取温度对CSP(compact strip production)冷轧深冲板的性能、组织和织构的影响。CSP热轧板组织主要为多边形铁素体,随卷取温度降低,晶粒尺寸略有减小。660℃和680℃卷取的成品冷轧板组织为等轴晶粒,卷取温度不超过600℃时则以"饼型"晶粒为主。力学性能测试表明,低于600℃卷取的成品板屈服强度和抗拉强度较低,其加权平均塑性应变比(rm)可达到1.80以上,伸长率超过49%。随卷取温度升高,成品板的{001}〈110〉和{110}〈110〉织构的取向分布密度逐渐升高,{111}织构取向分布密度先升高后降低,{111}〈110〉和{111}〈112〉织构取向分布密度差值也是先升后降。  相似文献   

18.
分析Zr-4合金板材真空退火过程中的传热方式,计算锆合金板材径向传热系数,利用ABAQUS对Zr-4合金板材退火温度场进行数值模拟,分析工装夹具对锆合金板材退火的影响,结果表明,工装夹具能改善锆合金板材温度场分布均匀性,使锆合金板材温度分布的最高温差由70 ℃降低至35 ℃,升温过程更加稳定,并且数值模拟结果与实测结果有较好的一致性。  相似文献   

19.
铝锌高阻尼板材的内耗特征   总被引:3,自引:3,他引:0  
论述了Al-Zn高阻尼合金板材在不同工作状况(温度、振幅、频率)条件下的内耗特征,同时还与纯铝板的内耗进行了比较。  相似文献   

20.
Abstract

One of the most important issues in resistance spot welding of three‐sheet stack joints is the insufficient growth of the weld nugget, which may cause problems in places needing larger weld nuggets (i.e. sheet/sheet interface). In this paper, the effect of sheet thickness on the pattern of weld nugget development during resistance spot welding of three‐steel sheets of equal thickness is studied. Results showed that there is a critical sheet thickness of 1·5?mm at which the fusion zone size at the sheet/sheet interface is nearly equal to the fusion zone size at the geometrical centre of the joint. Increasing the sheet thickness beyond the critical size causes a shift in the location of weld nugget formation from the geometrical centre to the sheet/sheet interfaces. Below the critical sheet thickness, the weld nugget growth in the geometrical centre of the joint is higher than that in the sheet/sheet interface.  相似文献   

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