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基于正交试验和灰色系统理论的拼焊板前纵梁成形优化 总被引:2,自引:0,他引:2
影响拼焊板冲压成形的工艺参数较多,难以精确建立工艺参数与成形质量之间的关系。以压边力、拉延筋高度、凸筋圆角半径、凹筋圆角半径为自变量,进行四因素四水平正交试验,模拟拼焊板前纵梁拉延成形过程,获得最大减薄率和最大焊缝移动量的数据。利用灰色系统理论,分别计算成形工艺参数对单目标函数的关联系数和多目标函数的关联度,将多目标转换为以关联度为目标的单目标。进一步计算各成形工艺参数的平均关联度,将优化的压边力、拉延筋截面几何参数进行有限元模拟验证,指导设计、试模,成形的质量得到明显提高。 相似文献
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基于正交试验和灰色系统理论的高强钢厚板折弯优化成形模拟及实验 总被引:2,自引:0,他引:2
影响高强钢厚板弯曲成形的工艺参数较多,难以精确建立工艺参数与成形质量之间的关系。文章以凸模圆角半径、摩擦系数、冲压速度为自变量进行三因素三水平正交试验,模拟Q550钢15mm厚板弯曲成形过程,获得回弹角和最大成形力的数据。利用灰色系统理论,分别计算成形工艺参数对单目标函数的关联系数和多目标函数的关联度,将多目标转换为以关联度为目标的单目标;进一步计算各成形工艺参数的平均关联度,将优化的凸模圆角半径、摩擦系数、冲压速度等参数进行有限元模拟验证,经理论指导设计、试模,其成形的厚板质量得到明显提高。 相似文献
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对盒形件凸缘直边法兰区主应力进行了力学分析,研究了其成形中法兰部分的变形情况.运用DYNAFORM软件,对盒形件的成形进行了数值模拟,并用硬度计测定了盒形件法兰区的硬度.结果表明:法兰直边靠近中点的材料比靠近圆角部分的材料厚度大,说明材料塑性变形不够充分;长宽比大的盒形件成形后的零件厚度比较大,材料流动困难,不利于成形;同一高度上,圆角部分硬度明显大于相邻两直边硬度,说明圆角部分材料流动良好而加工硬化现象明显,硬度最大值在凹模圆角入口处附近.盒形件法兰变形的实验与数值模拟结果一致. 相似文献
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《组合机床与自动化加工技术》2016,(2)
采用粒子群优化算法对摆线针轮行星传动进行约束多目标优化设计,求出满足约束条件的Pareto解集。考虑工程实际中误差的客观存在,进行了7因素9水平的均匀试验设计及望目特性的信噪比计算,在此基础上,依据多目标稳健优化设计原理在Pareto解集中选择最稳健的设计做为最终方案。分析了结果方案中目标函数(体积函数和修形误差函数)对各个设计变量的灵敏度,得出了目标函数最为敏感的因素及各因素对目标函数的影响程度用于指导公差的制定和实际加工制造。 相似文献
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针对汽车鼓式制动器,提出以制动效能因素最大、制动过程中温升最低、制动鼓体积最小为目标,进行多目标优化设计.应用惩罚函数法建立了优化目标函数,运用MATLAB遗传算法工具箱进行寻优求解,并通过实例进行验证.结果表明:该优化方法合理可行. 相似文献
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Nguyen Duc Toan Choi Seogou Park Junyoung Suh Yeongsung Kim Youngsuk 《Journal of Materials Engineering and Performance》2009,18(8):1005-1011
Door hinges are a key product in the automotive industry. The function of automotive door hinge is not only to close, open,
and keep the open angle of the door but also to reduce traumas for passengers in the car when it is hit by another car. However,
concentrated stress and strain occur at the corner of this product during forming, which can cause a crack if the shape of
this area of the blank is not carefully designed. Accordingly, this article proposes a method for improving the press formability
of a door hinge by changing the shape of the concerned area of the blank based on finite element method (FEM) simulations
using the explicit dynamic code ABAQUS, version 6.5. The resulting optimized solution for robust forming was a corner radius
of 7 mm, protrusion length of 18 mm, and protrusion height of 5 mm. 相似文献
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周杰 《锻压装备与制造技术》2007,42(4):51-53
近年来,计算机技术和分析金属板料成形过程的有限元理论得到了快速发展,这使得应用于金属流动过程的模拟仿真在降低实验成本,缩短研制周期,提高模拟结果可信度以及改善产品质量等方面发挥了越来越重要的作用.本文通过计算机辅助建模和有限元数值模拟软件Dynaform对LCD仪表盘盖板的成形性能和坯料尺寸优化进行了分析.比较了不同R值处,转角和边缘部分的高矮偏差,以及坯料的理论计算尺寸和通过Dynaform模拟所得的最优坯料尺寸.为了保证坯料高度,放大坯料尺寸进行了第二次模拟.在另外一个对局部塑性变形和金属流动的模拟仿真中,阐述了圆角半径小于板料厚度对成形的影响. 相似文献
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本文用大变形刚塑性有限元模拟正方形板料在方冲头拉延下的凸缘变形过程,并以所获得的工件形状与金属流动方向为依据,对初始板料形状进行修正。对修正后的坯料形状进行二次模拟,获得了与给定凸缘形状基本吻合的拉延件形状。文中对不同凸缘圆角对极料优化形状的影响作了计算,讨论了在保证边界轮廓位置不变的条件下网格划分的方法。 相似文献
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对汽车超高强度硼钢A柱加强板拐角开裂、起皱问题的优化方法进行了研究。利用CAE仿真软件AutoForm创建分析模型,进行热成形冲压仿真模拟分析,分析结果表明,该A柱加强板的拐角处易出现开裂和起皱现象。重点对起皱、开裂问题的原因进行了分析,认为产品结构不合理和工艺补充不优是造成拐角起皱、开裂的主要原因。从产品结构、工艺补充、坯料尺寸方面,经过多轮优化分析,有效地解决了A柱加强板拐角处的成形性问题。依据最优方案进行热成形工艺模具结构设计,经过铸造、机加、研配制造出满足设计要求的模具结构,并进行上机现场调试,调试结果与前期CAE分析结果一致。研究结果表明,前期CAE优化分析结果可以有效地指导现场生产调试,解决了拐角处的成形性问题,最终调试出合格产品,减少了零件开发的成本和周期。 相似文献
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K. Mori S. Nishijima C.J. Tan 《International Journal of Machine Tools and Manufacture》2009,49(10):767-772
A two-stage cold stamping process for forming magnesium alloy cups having a small corner radius from commercial magnesium alloy sheets was developed. In the 1st stage, a cup having large corner radius was formed by deep drawing using a punch having large corner radius, and the corner radius of the cup was decreased by compressing the side wall in the 2nd stage. In the deep drawing of the 1st stage, fracture was prevented by decreasing the concentration of deformation with the punch having large corner radius. The magnesium alloy sheets were annealed at 500 °C to increase the cold formability. Circular and square cups having small corner radii were formed by the two-stage cold stamping. For the circular cup, the height of the cup was increased by ironing the side wall in the 1st stage. The radii of the bottom and side corners of the square cup were reduced by a rubber punch for applying pressure at these corners in the 2nd stage. It was found that comparatively shallow magnesium alloy square cups used as cases of laptop computers and mobile phones can be satisfactorily formed at room temperature without heating by the two-stage stamping. 相似文献
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Hong Yao Brad L. Kinsey Jian Cao 《International Journal of Machine Tools and Manufacture》2000,40(1):113
With the development of finite element method and computer technology, the complete modeling of the forming of a 3D sheet metal part is becoming realistic. However, an accurate 3D simulation is usually too time-consuming to be used in the early stage of design. One solution is to model the straight side of a 3D part as a plane strain problem and the corner section as an axisymmetric problem. Unfortunately, the axisymmetric solution often over-predicts the severity of the deformation at the corner and leads to a very conservative design. In this study, a modified axisymmetric model with a center offset is proposed to predict tearing failure in the corner sections of 3D parts. The proposed offset is found to be a function of the center strains, failure height, and tooling/process parameters, including tooling geometry, material properties, friction coefficient, and restraining force provided by the binder. Finite element analyses of both 3D and 2D axisymmetric models for square and rectangular cup forming are utilized to verify the proposed concept and to define the function. Excellent predictions of the failure heights are obtained. The proposed model enables engineers to rapidly specify the right amount of the restraining force in the corner section based on the desired center strains and forming depth. A detailed design algorithm is provided. 相似文献
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雷建波 《锻压装备与制造技术》2014,(2):56-58
齿轮轴成形属于精密成形过程,其预制坯形状对终锻成形质量有至关重要的影响。本文以影响预制坯成形过程中的4个工艺参数——凸模速度、摩擦因数、预锻凸模拐角斜度、预锻凹模斜度为设计变量,终锻成形载荷与坯料充填情况为目标函数,利用正交试验,选用了4因素3水平进行试验方案设计,利用Deform-3d软件分别模拟分析了各个不同试验方案,得到了最佳工艺参数组合,并通过模拟验证该优化方案的正确性。试验结果对生产实际具有一定指导意义。 相似文献