城轨车门角件拉延成形数值模拟研究

发布时间：2018-05-06 23:00

本文选题：拉延成形 + 门角件　；参考：《吉林大学》2017年硕士论文

【摘要】：城市轨道列车因其快捷、高效的特点逐渐成为人们出行的首选,成功地解决了大中城市的交通拥堵问题。目前的轨道车辆车体材料主要有两种:不锈钢和铝合金。不锈钢车体因其优良的力学性能和耐高温、耐腐蚀等优点而被广泛应用于城轨车体制造。其中,常温下显微组织为奥氏体的SUS301L不锈钢,由于其超细晶组织和TRIP效应而具有较高的强塑积,非常有利于车体轻量化设计,具有更全面、更优良的综合性能,是城轨列车车体的首选材料之一。门角件主要用于连接车门顶柱和车门侧柱,具有强度高、抗变形等特点。该门角件的平面与侧壁成90°连接,连接处一端为圆弧连接,一端为倒角连接,倒角长度连续可变。这样复杂的空间结构使得成形过程中平面与侧壁连接处的金属流动速率各不相同,板料在倒角连接处的流动阻力相比圆弧连接处的阻力大,因此板料在倒角连接处流动困难,极易出现起皱现象,进而造成门角件平面部分变形不充分,存在大面积的拉延不足缺陷。且不锈钢抗拉强度及应变硬化指数较高,卸载后90°角回弹较大,在传统成形方法中需要通过整形工序得到形状尺寸符合要求的零件。为了优化冲压成形工艺、节省模具设计时间、提高成形件形状尺寸精度,本文利用CATIA软件,设计了国内某城轨车辆SUS301L不锈钢门角件的成形模具,并利用Auto Form有限元软件对该类拉延深度大、空间结构复杂、厚度较大零件的成形过程进行模拟分析。首先研究了不同形式布置的拉延筋以及拉延筋系数对板料成形质量的影响,再通过调整压边力、凸凹模间隙、凹模圆角半径及摩擦系数等工艺参数,来分析各参数对门角件成形质量的影响规律以优化工艺,提出了控制成形缺陷的有效方法。结果表明:优化成形工艺可一定程度上消除拉延不足、起皱缺陷,提高门角件轮廓精度,使90°角的回弹量控制在合理范围内。通过成形试验,得到了合格的成形件,验证了模拟结果的准确性。
[Abstract]:Because of its fast and efficient characteristics, urban rail train has gradually become the first choice for people to travel, and has successfully solved the problem of traffic congestion in large and medium-sized cities. At present, there are two main rail vehicle body materials: stainless steel and aluminum alloy. Stainless steel carbody is widely used in the manufacture of urban rail car body due to its excellent mechanical properties, high temperature resistance, corrosion resistance and other advantages. Among them, SUS301L stainless steel with austenitic microstructure at room temperature has a high strength plastic product due to its ultrafine grain structure and TRIP effect, which is very beneficial to the lightweight design of the carbody and has more comprehensive and better comprehensive properties. It is one of the first choice materials for the body of city rail train. Door corner is mainly used to connect door top column and door side column with high strength and anti-deformation. The plane of the door corner is connected with the side wall at 90 掳, one end of the connection is arc connection, one end is chamfer connection, and the chamfer length is continuously variable. Such complicated space structure makes the flow rate of metal at the joint of plane and side wall different in the forming process, and the flow resistance of sheet metal at the chamfer joint is larger than that at the arc joint, so it is difficult for the sheet metal to flow at the chamfer joint. It is easy to appear wrinkle phenomenon, which leads to insufficient deformation of the plane part of the door corner, and the defect of insufficient drawing in a large area. The tensile strength and strain hardening index of stainless steel are high, and the springback of 90 掳angle is large after unloading. In order to optimize the stamping process, save the design time of the die and improve the shape and dimension precision of the forming parts, the forming die of the SUS301L stainless steel door angle part of a city rail vehicle in China is designed by using CATIA software in this paper. The forming process of this kind of parts with large drawing depth, complex space structure and large thickness is simulated and analyzed by Auto Form finite element software. Firstly, the influence of different forms of drawing bars and the coefficient of drawing tendons on the forming quality of sheet metal was studied. Then, by adjusting the blank holder force, the clearance of convex and concave die, the radius of groove and friction coefficient of die, etc. In order to optimize the forming process, an effective method to control the forming defects is put forward by analyzing the influence of various parameters on the forming quality of the corner parts. The results show that the optimum forming process can eliminate the drawing deficiency and wrinkle defect to some extent, improve the contour precision of the door angle, and control the springback of 90 掳angle within a reasonable range. Through forming test, qualified forming parts are obtained, and the accuracy of simulation results is verified.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U270.6;TG386.32

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