《中衡外文翻译--热挤压模具的优化【设计明细】-精品.pdf》由会员分享，可在线阅读，更多相关《中衡外文翻译--热挤压模具的优化【设计明细】-精品.pdf（13页珍藏版）》请在taowenge.com淘文阁网|工程机械CAD图纸|机械工程制图|CAD装配图下载|SolidWorks_CaTia_CAD_UG_PROE_设计图分享下载上搜索。
1、Stress Analysis and Optimum Design of Hot Extrusion DiesStress Analysis and Optimum Design of Hot Extrusion DiesAbstract:Abstract:A three-dimensional model of a hot extrusion die was developed by usingANSYS software and its second development language ANSYS parametric designlanguage.A finite element
2、 analysis and optimum design were carried out.Thethree-dimensional stress diagram shows that the stress concentration is rather severein the bridge of the hot extrusion die,and that the stress distribution is very uneven.The optimum dimensions are obtained.The results show that the optimum height of
3、the extrusion die is 89.596 mm.The optimum radii of diffluence holes are 65.048 mmand 80.065 mm.The stress concentration is reduced by 27%.Key words:Key words:three-dimensional method;modeling;hot extrusion die;optimum designIntroductionIntroductionWith the continuous improvement of living standards
4、,better thermal conductivityof aluminum alloy profiles.Aluminum components widely used in every aspect of life.Therefore,the aluminum alloy extrusion profiles,profiles of various types of radiatorshave been widely used in electrical appliances,machinery,and other industries.Variable products and the
5、 growing diversity and complexity of high-precision,theextrusion process is the basis for extrusion die.It not only determines the shape,size,accuracy and surface state,but also affect the performance of the product.Soextrusion die extrusion technology is the key.Studies to improve extrusion die qua
6、lity and prolong its life span usually attempt tosimplify 3-D finite element model to 2-D,but it is only right for simple structuralshapes.Without a 3-D finite element analysis,the results cannot give practicalmanufacturing help and offer useful information3-5.In this paper,aluminium prodie was mode
7、led to get in optimum design6-8.1 Solid Modeling1 Solid ModelingFigure 1 shows the male die of a hot extrusion planar combined die.Its externaldiameter is 227.000 mm,its height is 80.000 mm.Other parameters are shown in Fig.1.The modeling method is as follows.1.1 Coordinates of1.1 Coordinates of P P
8、1 and1 and P P5 5The coordinates of the point of intersection between the beeline L(y=kx+b)andthe circular arc(x2+y2=R2)are1.2 Coordinates of1.2 Coordinates of P P2 and2 and P P6 6The coordinates of the intersection point(P2)between beeline L1(y=kx+b)andbeeline L2(y=S1)areThe coordinates of the inte
9、rsection point(P6)between beeline L3(y=kx+b)andbeeline L4(y=S1)are1.3 Coordinates of1.3 Coordinates of P P3,3,P P4,4,P P7,and7,and P P8 8P3 and P1 are symmetric about the y-axis.P4 and P2 are also symmetric about they-axis.P7 and P5 are symmetric about the x-axis.P8 and P6 are also symmetricabout th
10、e x-axis.1.4 Variables in the equations1.4 Variables in the equationsIn Eqs.(1)-(6),for points P1 and P2,and R=R1.For points P5 and P6,and R=R2.R1,R2,T1,T2,S1,and S2 are the change rule along the height(H)of the dieexpressed as the functions R1=f1(z),R2=f2(z),T1=f3(z),T2=f4(z),S1=f5(z),andS2=f6(z),z
11、 0,H.1.5 Section shape at some height1.5 Section shape at some heightWith lines linking P1-P4,P5-P8,with circular arc filleting at the point ofintersection(P1-P8),the section shape at some height is obtained.1.6 Section shape at every height1.6 Section shape at every heightH is divided to interfacia
12、l number(INUM)equal parts(INUM is decided by theprecision,if the INUM is higher,the precision is better).The section shape is drawn atevery height as shown in Fig.2.1.7 Smooth curved surface1.7 Smooth curved surfaceUsing SKIN command in ANSYS,smooth curved surfaces were built alongthelines.They are
13、the surfaces of the influence hole.Using the VA(it generates a volumebounded by existing area)command,a solid was created from those surfaces.1.8 Symmetry of the die1.8 Symmetry of the dieThe main body and kernel of the die were drawn using the Boolean operations ofadd,subtract,etc.(Fig.3).The symme
14、try of the die was used to accelerate thecomputations using a 1/4-solid model for the finite element analysis(Fig.4).2 Computing Model2 Computing ModelA planar die that extrudes the aluminium alloy(6063Al-Mg-Si)was used as anexample.The liquidoid of Al is 657 9,and the melt temperature of Al+Mg2Si i
15、s558.Taking the extrusion pressure and the products quality into account,theworking temperature was determined to be 450.The die material is 4Cr5MoSiV1(H13).Below the 450,its Young modulus andPossion ratio are 210 GPa and 0.25,respectively.Its yield strength is 1200MPa.Thefriction coefficient is 0.3
16、.The Solid92 3-D solid element was used to carry throughthe free mesh.In order to load the frictional force while extruding,the surface effectelement Surf154 was used to produce the regular quadrangles(Fig.5).For the 1600 textruder,the extrusion intensity was computed using Eq.(7)10.The values aresh
17、own in Table 1.The bridge collapse often takes place in the die.And its strength is determined bythe height and the distribution of the diffluence holes.In this paper,the height(H)andthe radii(R1 and R2)of the diffluence holes were used as design variables and themaximum equivalent pressure(smax)was
18、 used as the goal function.The designvariable ranges are listed in Table 2.3 Computed ResultsFigure 6 is the equivalent stress diagram.From Fig.6 we can see that the stress islargest at the bridge,as expected 24 maximum equivalent stress values are listed inTable 3 from large to small.The data shows
19、 that the nodal maximum equivalent stressis 1066.5 MPa,which is 14.5%higher than the second one(912.0 MPa),and that thestress convergence is very severe in the bridge,this part is apt to produce crack.The initial value of the design variables R1,R2,H,q1,and q2 were 75.000 mm,88.000 mm,80.000 mm,30.0
20、00,and 30.000,respectively,and the maximumequivalent stress smax=1066.5 MPa.In the 21 iterations,the optimum iteration wasthe eighteenth.The design variable values were R1=65.048 mm,R2=80.065 mm,H=89.596 mm,q1=30.642,q2=20.045.The maximum equivalent stress smax=723.1MPa,which is 27%less.The optimum
21、results are shown in Table 4.4 Conclusions4 Conclusions1)Based on ANSYS software,its second development language APDL was usedto develop a 3-D model of the hot extrusion die that extrudes aluminium pro beenobtained.2)The 3-D stress distribution was very uneven,with severe stress concentrationsin the
22、 bridge of the hot extrusion die.The optimal geometric design had 27%lowermaximum stress,A better die will not only reduce die number but also reduce timelost changing dies,which will greatly heighten productivity.3）Die cantilever design of large-scale streaming into false structure Not only iseffec
23、tive to reduce the pressure on the mold to take greater positive die as a result ofdangerous sections of the fracture.greatly extend the life of the die,but this can notbring streaming bridge structure also more effective to reduce the thickness of thebottom die velocity,the velocity Extruded ensure
24、 a balanced,stable.Meanwhile,thestructural design of the extrusion die for the wide disparity in thickness solid ProDesign,opened up a new way of thinking and approach.ReferencesReferences1 Karacs G.Computer aided methods for die design.Proceedings of the Conferenceon Mechanical Engineering,1998,2 2
25、:463-466.2Mueller G.Design optimization with the finite element program ANSYS.International Journal of Computer Applications in Technology,1994,7 7:271-277.作者：帅词俊;肖刚;倪正顺;英文作者：SHUAI Cijun*;XIAO Gang;NI Zhengshun College of Mechanical andElectronic Engineering;Central South University;Changsha;China;刊
26、名：Tsinghua Science and Technology,清华大学学报(英文版),编辑部邮箱2004年 03期查询来源：查询网址：中国学术期刊全文数据库热挤压模具的优化设计热挤压模具的优化设计摘要摘要：热挤压模具立体模型开发利用 ANSYS 软件及其二次开发语言 ANSYS 的参数设计，进行有限元分析和优化设计。热挤压模具的三维应力分布很不均匀,悬臂梁有严重的应力集中。获得最佳 层面，数 据结果表明 最佳的 高度是89.59630.1+5.6。挤压模分流孔是最佳半径 80.06565.048 毫米和毫米，应力集中减少了 27%。关键词关键词：三位一体方式，造型，热挤压模具，优化设计引
27、言引言随着生活水平的不断提高,由于铝合金型材的导热性能较好，铝零件广泛应用于生活中的每一环节。因此，在铝合金的挤压型材中，各种类型的散热器型材已被广泛地应用在电器、机械等行业中。产品变的日趋多样化、复杂化和高精密度化，挤压模具是基础的挤压工艺。它不仅决定着产品形态、大小、精度和表面状态,而且影响到产品的性能。所以挤压模具是挤压技术的关键。挤压模具研究改进质量和延长其寿命通常试图将三维有限元模型简化为二维,但只不过是构造简单的结构形状。没有三维有限元分析,其结果不能给制造业提供实际帮助和提供有用的资讯。本文主要介绍铝型材挤压模具优化设计模型。1 1 实体造型实体造型图 1 主要显示一种平面组合的
28、热挤压模具。其外部直径为 227.000 毫米,其高度为 80.000 毫米。其他参数见图 1，建模方法如下：1.11.1 坐标坐标 P1P1 和和 P5P5直线L(y=kx+b)和圆弧(x2+y2=R2)之间的相交点坐标是1.21.2 坐标坐标 P2P2 和和 P6P6直线 L1(y=kx+b)和直线 L2(y=S1)之间的相交点坐标 P2 是直线 L3(y=kx+b)和直线 L4(y=S1)之间的相交点坐标 P6 是1.31.3 坐标坐标P P3,3,P P4,4,P P7,7,和和 P P8 8P3 和 P1 是关于 Y 轴对称。P4 和 P2 也是关于 Y 轴对称。P7 和 P5 是关
29、于 X轴对称。P8 和 P6 也是关于 X 轴对称。1.41.4 变量方程变量方程由公式(1)-(6)，得点 P1 和 P2，和 R=R1.得点 P5 和 P6，和 R=R2。R1,R2,T1,T2,S1 和 S2 是 沿 着 高 度(h)的 变 化 规 律 来 表 达 模 具 的 功 能R1=f1(z),R2=f2(z),T1=f3(z),T2=f4(z),S1=f5(z),和S2=f6(z),z 0,H。1.51.5 在一些高度的部分形状在一些高度的部分形状用直线连接P1-P4,P5-P8,蘖与圆弧相交于点(P1-P8),在一些高度获得了部分形状。1.61.6 在每一高度的部分形状在每一高
30、度的部分形状高度划分为若干界面(微粒)等部分(微粒决定着精密，如果微粒较高的,精度更佳)。在每节高度形状如图2所示。1.71.7 光滑曲面光滑曲面在ANSYS使用表面指挥,顺利沿直线建立曲面，他们是影响面孔。利用VA(它利用现有的面积产生一定容量)指挥,从创立了坚实的表面。1.81.8 对称性模具对称性模具主体和核心的模具画图时用布尔操作增加,减掉等(图3)。对称性模具用于加速计算时使用的有限元分析模型为1/4-实体模型(图4)。2 2 计算模型计算模型用挤压铝合金(6063Al-Mg-Si)的一个平面模具来作为例子。铝的液相是6579,Al+Mg2Si的熔体温度是558。考虑到产品质量和挤压
31、压力,工作温度定为450。模具材料是 4Cr5MoSiV1(H13)。下面是 450,它的华模和泊松比分别是210GPa和0.25。其屈服强度是1200mpa，摩擦系数是0.3。固92通过免费网用来传送三维实体元素。为了负荷的摩擦力而挤压，表面效应单元154经常被用来生产组合体(图5)。用挤压机为1600吨,挤压强度计算公式为(7)10。其值见列表1。桥梁倒塌经常是由于挤压，其高度和力量是分布在分流洞。本文中,高度(H)和半径(R1 and R2)是分流孔的设计变量,作为最高压力(smax)相当于作为目标的功能。设计可变幅度如下列表 2.3 3 计算结果计算结果图6相当于应力图。从图6中我们能
32、看见最大的压力是在桥臂上，预计最大应力值等于24 从大至小见列表3。数据显示,最高相当于节点应力1066.5 MPa，这是14.5%,高于二之一(912.0 MPa)，这是非常严重的收敛压力,在悬臂上这部分是容易产生裂缝的。初步设计变量值R1,R2,H,q1,and q2 分别是75.000 mm,88.000 mm,80.000mm,30.000,and 30.000,最大当量应力 smax=1066.5 MPa。在迭代21时,最佳迭代是第十八。设计变量值R1=65.048 mm,R2=80.065 mm,H=89.596 mm,q1=30.642-,q2=20.045。最高压力相当于 sm
33、ax=723.1 MPa,即减少27%。最佳结果见如下列表4。4 4 结论结论1)基于ANSYS软件，三维模型用于研制二次开发语言APDL，它是根据铝热挤压模具概况取得。2)热挤压模具的三维应力分布很不均匀,悬臂梁有严重的应力集中。最优几何设计最大应力降低了27%,一个好的模具不但可减少模具加工人数也减少改变模具损失的时间，这将大大提高生产率。3）将大悬臂的铝型材模具设计成假分流模的结构，不仅有效地减小了由于模具承受较大的正面压力所导致的模孔危险断面的断裂，极大地延长了模具的使用寿命，而且，这种带不分流桥的结构，还有效地减小了模孔底部较大壁厚处的流速，确保了挤压型材流速的均衡、平稳。同时，这种
34、结构的挤压模具设计方案，为壁厚相差悬殊的实心型材模具的设计，开辟了新的思路和途径。参考文献参考文献1Karacs G.Computer aided methods for die design.Proceedings of the ConferenceonMechanical Engineering,1998,2 2:463-4662Mueller G.Design optimization with the finite element program ANSYS.InternationalJournal of Computer Applications in Technology,1994,7 7:271-277