冲压模表面设计外文翻译.docx

附录1 中文译文冲压模表面设计1、引言据悉，金属板料冲压模产品的关键部分是从本质上发展模具的表面设计，在必需的质量范围内找准刀具表面几何形状以得到一个完全改进型坯料的外形冲压成形。冲压刀具的设计原理以零件几何学作为基本输入数据和为了一个特定的捣实模板用工程法设法去决定操作的最小数，目的是当满足客观的冲压标准时，以减少成形刀具的成本。这个工程方法为形成工艺流程设计连续运转到最后的车间传导各式各样的试验，直到出现大量的冲压零件产品阶段为止。在冲压模具表面设计和可使用性塑料的金属片之间决定着空缺变形的特性，另外应该考虑到要形成高强度钢以适应降低的可模锻性和提高弹性变形。通过符合计算机辅助设计和分析刀具的模具试验阶段，会在计算机里产生可靠的实质性的设计环境，以及方法和利用基于仿真有限元素的方法预先实现可成形性问题的刀具工程学，例如，裂缝、皱纹或过分的稀释，以及捣实模板涉及到的模具表面设计。它也能够在清理焊缝和弹性变形后估计出最后的几何形状。这种工程学接近于在制图过程中假设模具表面变形被忽略了，以及在传统的钢中，工业实践已经被有效的证实了这个假设有大的内部嵌板模。这就是理想严格的模具概念，然而，当提到形成新的高强度的中等浓度钢变的可辩论起来了，由于更大的模具表面的扭曲，由于关连到更高的组成强度，就可能不再不是认为无意义的了。因此，在生产之前，模具表面变形和它的牵连应该连同模具设计图一起被考虑，在这篇论文里，按照一个简短的冲压模设计原则的回顾，在板料金属的形成过程中，一种估计和控制模具表面变形的计算方法被提出，在第一部分和第二部分的研究中，基于计算机辅助设计和分析定义，醋酸丁酸纤维素体成份的形成过程中，这种被提议的方法被应用，在模具加工过程的计算机辅助设计中，零件的可成形分析和弹性变形及加工变形，模具表面设计变形，以及想的刚性和可变形界面相对差都考虑了，通过增加冲压铸件的壁厚来执行理想刚性模具表面设计的假设。2、模具表面设计的概念金属片形成模具的表面设计可以被定义为在确保刚性结构条件下，使金属片铸塑成一种理想的冲压形状，使之成为完整的表面几何形状的一部分。这种设计过程始于零件的几何形状作为基本输入数据，提出这种方法的工程师首先通过推翻最有利的轴线和排除了冒险的切口对制图的说明书作出了决定，因而，利用材料的可成形性和最小允许的厚度，取决于拉伸成形的数量和估计拉伸操作的次数，设计者运用金属片零件半厚度偏移几何学，在计算机辅助设计的环境中，通过延长零件的边缘，嵌缝锋利的刃口，伸展法兰的形状为冲压表面设置了额外的表面。利用材料特性和最大拉伸变形的次数，估计出可完成的最大化图形进深，并且一系列的连接杆和计数管的表面可被额外的穿孔和冲模，目的是在形成过程的初始阶段最小化变形斜度，在对冲压操作之后，用一系列平面和可曲展面来产生组合的几何面，通常在焊头和焊尾的连接之间用一种控制方式来抑制材料在冲压时溢出，在冲压和粘接分界面的形成之后，他们通常由排除分界面数量的偏置法来发展相似几何学，这是用cad软件典型的板材大于金属片几个百分点的厚度，现阶段允许使用的部分变薄,拉伸，并做空白大小可利用估算恒定假设。一旦工程师创造了整个几何方法描述的空白,并在计算机辅助环境下进行模具表面设计，用有限元分析可完成以调查过程的可行性成形、 几何部分回弹后形成刚性模量假设的理想的有限元模拟及施工。随着加入的金属厚度分布，冲压过程通常是做两步，一种是进行形成分析,确定某一变形金属冲压、装粘合剂,其次是移动后的弹性变形的计算与成型模具应力、变形几何学。依靠相对质量的过程与材料参数, 几个虚拟试验要必须达到最佳成型模具及几何要素。此时, 成形载荷类型和图形作用,是根据现有的冲压路线规定的。最后,完成冲压模具表面的校准,并提交模具建筑业和制造业部门。在汽车行业,冲压模具设计与施工实践,采用按类型的板材和借鉴行动，按照所选类型制造冲压模,通常 一项内部模具设计与施工的选材标准是其次的要件，包括详细的模具，铸造、热处理规范程序。用发展模面设计为冲压的起始尺度、上下结合分子，是指导该内部标准是受制于标注与融合的主要构件元素。如上下模适配器板、冲床、铸造粘结剂、导柱和引导套管磨损板. 另外,通过选择运用冲压刀具，撑架-几何学、冲床冲压成型模具完全确定建造和使用于cad系统，这一阶段的设计工程师,允许建立虚拟原型上、下半片的成形，模具用一些几何参数,如内部闭合高度、内存储金属板、冲床、粘合剂壁厚或立体边平衡块. 一些位置分析冲模，拉深模和固定元素形成一个完整的循环进行干涉和控制,以消除滑枕行程和制图数量的不一致性。3、模具面形控制模具面形控制的成形过程是一个复合体系的组成、冲模 空白, 涉及机械、一套互动冲压，提供必要的基础结构和能源。假定一个理想的刚性压模构造相连了托板和理想的刚性冲压支承板，忽略所有模具表面的扭曲来帮助工程师设计形成过程的方法，成形过程只有按照纯图形表式法，否则，在形成过程中为了模拟板材变形反应，努力把所有这些系统力学模型去运算，这将是一个巨大的工程。这是最实际的做法,因此形成孤立接口,即模面设计和空白。从其余空白变形和模拟下形成压力产生摩擦接触，用纯几何描述模具表面设计. 此外, 这一主张在工业中已得到普遍使用,即使是在常规的金属板内部面板下. 最理想的观念吸取模施工,不过, 当谈到有可能成为可疑的形成是由于高强度钢的成形载荷较高. 此外,在产生信任方面形成规模结构部分与非对称分布,可能适用于很高负载平衡块板之间的磨损，在冲压和粘合剂之间增加磨损和扭曲的标签. 在这些变形模具的生产中，应列入计算模型的形成过程. 目前, 考虑计算机硬件跃进与有限元软件,建立一个计算机模型模拟系统是完全可以实现的, 然而由于高角度分析计算机时代, 基于个别特征的变形经验，一个完整冲压周期，从一个企业家的观念来看是几乎不可行的， 反而比较简单的实际工程方法是可解耦系统的冲压过程，加上部分组成空白模面设计、模具只完成部分拉深模具设计。与模具表面扭曲相比，审议过程只有部分时间依赖性的相互作用和成型板材空白界面带来大变化空白. 因此, 由于运动学特征的变形空白，基于增量应变和有限元素变形理论，模拟部分的过程应制定基于有限元大变形理论。在另一方面，在单一元素成形周期间，有小变形叠加过渡到大位移变形冲模的特点. 因此,小应变的弹塑性有限元分析得出的模具可能适合建作。两方的相互作用是指在计算适当的数据传输路线。在该部分过程中，成型模具资料模拟用几何面设计为刚性表面实体和空白作为弹塑变形体、时效位移驱动粘合剂、冲压成型工艺实现议案. 主要产生几何变形的应力分布和生产空白的历史后，回弹和成形载荷以及摩擦接触应力分布较大分子面前. 另一方面,为模具专用部分，负载历史形成的基本投入评估模具表面变形分析部分. 完全冲模设计模面材料点的有限元分析得出冲压周期的位移、只有对下一迭代更新模具表面设计可反馈过程的一部分。同时计算弹塑性应力应变在一个完整的历史循环和冲压同期之间的接触力冲压、粘合剂。通过相互借鉴模建筑元素，分子与平衡块板磨损带来了很大的启示。4、工业应用上一节，在刀具生产前，对于前道边体前冲压模具设计，工程概述方法论是利用结构评估冲压模具设计，如(fig. 2)。这部分是强度冲压能源管理结构的特性。 这种传统的设计方式是为大型构件利用吸取1.72.2 mm厚度的优质钢材。随着减重约10-15%， 商业可供1.5毫米高强度低合金钢与屈服应力、成形、中度变形，推出一个可行的能增大强度特性的替代品。成形工艺设计部分冲压形成纯几何造型做以下办法，所有模具表面变形假定,忽略了刚性冲压模具。利用三维cad模型的一部分, 首先进行的是一种损人利己检查,以确定是否可能形成一个单一的部分操作。随后对零件顶锥角尖端的调查表明， 三维旋转的部分是几何撞击运动方向，因此，零件被适当的放置在等压系统中，这种系统使坐标系统中的紧迫轴成平行于部分绘制轴线，如：(fig. 3).。利用三维cad模型的一部分，表面上一套模具的几何学产生了相当于抵消了一半的板材厚度，区编一套加上这套表面几何。自零件的边界线沿着曲线形成，是延长表面以下类似的几何形式和粘合剂，因此冲去粘合剂表面和法兰产生完整的模具及粘合剂表面上的冲压模具。 如：(fig. 4)。这一三维组合形式表面形成界面几何学，其他模具分子从中得到。在cad环境中，通过一个简单的几何复制，冲压和粘合剂界面被产生了。通过使用其对应的几何厚度冲抵正常的压力和方向。现阶段，完整的描述模具计算机辅助面设计,能够获得雇用的有限元网格，成形回弹的评估和分析。冲压，网状粘合剂、模具表面与21908三、四个节点壳单元共有，所有曲率是由六层分子描绘，如：(fig. 5)。5、总结本文，一个工程的定量评价方法，在设计过程中形成的板材冲压件，提出了精确的理想假说通常采用刚性模具。 以下简要回顾冲压模具设计实践，基于计算机辅助设计与分析概念的计算方法，并在第一部分和第二部分中，这项研究提出了测定与控制模面变形期间的形成过程。工业应用的基本步骤是用来展示、 双方更进一步的分析计算和模具表面变形的过程，是一个完整的冲压模具设计成形。可成形性和回弹变形过程进行分析，一个汽车冲压结构由部分高强度钢组成的。通过增强冲压件的硬度，在最后的冲压成形模具表面变形结果中，冲压形成决定的理想刚性和被论述的可变形的分界面之间有着不同的几何学。最高冲压表面变形发现有不到一半的厚度了，确认的空白界面形成了刚性假说。附录1 英文原文stamping die-face design1. introductionit is known that a crucial part of the production of asheet metal stamping die is essentially the development of a die-face design aiming a tooling surface geometry that gives a fully developed blank shape a defect-free stamping form within the necessary quality constraints. the design of stamping tooling elements starts with the part geometry as the basic input data and the methods engineers try todetermine the minimum number of operations for a given stamping form in order to reduce the forming tooling costs while satisfying the objective stamping criteria 1. the methods engineer conduct svarious tryouts for the forming process design continuing up to the end of workshop try-outs until to the mass production phase of the stamping part. since both the stamping die-face design and the plasticworkability of the sheet metal determine the characteristics of blank defor-mations, additional care should be paid in the forming of high strength steels to adapt to the lower formability and higher springback deformations 2. in line with the advance-ments in the computer aided design and analysis tools the die try-out phase may be carried out reliably in computer generated virtual design environment, and the methods and tool-ing engineering takes the advantage of the finite element method based simulation in the prediction of the probable formability problems, such as cracks, wrinkles or excessive thinning, related to the dieface designed for a given stamping form. it is also attainable to estimate the final part geometry after trimming operation and springback deformation. this engineering approach assumes that the die-face deformations during the drawing process are negligible and the industrial practice has proved the validity of this assumption for even large inner paneldraw-dies in the case of conventional draw-quality steels 3. the notion of an ideally rigid draw-die construction, nevertheless, becomes arguable when it comes to the forming of new class high strength steels of moderate thickness because of the bigger die-face distortions because of the relative high forming forces, which may be not consid-ered insignificant anymore 4. hence, the die-face deformations and its implications should be considered in connection with the draw die design before submitting to the production. in this paper, following a short review of the stamping die design practice; a computational methodology is presented for the assessment and control of die-face defor-mations during the sheet metal forming processes. the proposed approach is employed in the forming process design for a cab body member based on the computer aided design and analysis concepts given in part i and in part ii of this study. the die-face deformations are taken into account in the computer aided design of the processtooling.the part formability analysis and springback deformations are conducted including the tooling deformations. the relative differences between the ideally rigid and deformable forming interfaces are discussed, and the assumption of an ideally rigid die-face design is fulfilled by increasing the punch casting wall thickness.2. die-face design conceptsthe die-face design for a sheet metal forming die may be defined as the composition of a complete surface geometry that deforms a sheet metal blank plastically into a desired stamping shape by ensuring a rigid tooling construction. the design process starts with the part geometry as the basic input data, the methods engineer firstly decides on the drawing direction by tipping the part to the most favorable axis, and eliminating the risk of an undercut. then, using the material formability and minimum allowable thickness, the amount of stretching deformation is determined and the number of stretch-draw operations is estimated. using the half-thickness offset geometry of the sheet metal part the designer sets additional surfaces for the punch face by extending the part edges, filleting the sharp edges and by unfolding the flange-type of geometry in the cad environment. using the material properties and the amount of maximum stretching deformation, the maximum achievable drawing depth is estimated, and a set of drawbar and counter bar surfaces may be added to both punch and die in order to minimize the deformation gradient during the initial stage of the forming process. after deciding on the press operation type, the binder geometry is generated using a set of flat or developable surfaces, and usually integrating with the draw-bead and contra-bead elements in order to restraint the material flow over the punch in an controlled manner 5. after the creation of punch and binder interface, their geometric counterparts are developed usually by offsetting the surfaces with a clearance amount that is typically a few percent larger than the sheet metal thickness using the cad software.at this stage using the allowable thinning of the part, the amount of stretch, and the blank size estimate may be done using the volume constancy assumption. once the methods engineer has created a entire geometric description of the blank and die faces in a cad environment, the finite element analyses may be performed in order to investigate the process feasibility in terms of the formability, part geometry after springback and forming loads by assuming an ideally rigid die construction 6,7. the finite element simulation of the stamping process is done usually in two steps. a forming analysis is conducted to determine the metal deformation for a given punch and binder loading and, secondly, the springback deformations following the removal of the tooling is computed with the forming stress distribution and the deformed geometry from the forming step as the inputs along with material thickness distributions8. depending on the relative qualities of the processand material parameters, several virtual try-outs may be necessary in order to reach the optimum tooling geometry and forming elements. at this point, the forming loads and the type of draw action is determined in accordance with the available press line specifications. finally, the complete stamping tooling surface is approved and submitted tothe draw die construction and manufacturing department. in the automotive industries, the design and construction practice of stamping dies is adopted according to the sheet metal type and draw action in accordance with the type of the chosen manufacturing press 1,3,9. usually, an in-house die design andconstruction standard is followed in the material selection for the die elements including the detailed specification of casting and heat treatment procedures. using the developed die-face design as the starting dimensions for the punch, upper and lower binder elements, the guidelines given in the in-house standard are employed in the dimensioning and integration of the major structural elements, such as the lower and upper die adaptor plates, punch and binder castings, guide post and bushings and wear plates. additionally, by selecting press tool action, the bolsterram geometry and punch stroke completely define the forming die construction4,10. the use of acadsystemat this phase allows the design engineer to build a virtual prototype of the upper and lower halves of the forming die using a number of geometry parameters such as the inner ram shut height and the geometry of the adaptor plate, punch and binder wall thickness or position of blankholder balance blocks. anumber of position analyses of the punch, die and blankholder elements during a complete forming cycle are conducted to control the interference and overlap to eliminate any inconsistency between the ram stroke and amount of drawing.3. the die-face shape controlthe sheet metal forming process is a compound system made up of the stamping die and the blank, and involves a set of mechanical interactions with the press and the foundation structure that provide the necessary forming energy4,5,10,11. assuming an ideally rigid die construction connected to the ram and bolster plates of an ideally rigid press and neglecting all die-face distortions help the methods engineer designing the forming process following a pure geometric modeling procedure only 25. otherwise, it would be an enormous engineering effort to include all of these mechanical systems in a computational model that is intended to simulate the sheet metal deformation response during the forming process. it is therefore the most practical approach to isolate the forming interface, i.e., the die-face design and the blank, from the remaining, and to model the blank deformations under the forming forces generated during the frictional contact with the purely geometric description of the die-face design. moreover, this proposition has found widespread use in the industry for even large inner panel draw-dies in the case of conventional sheet metals.the notion of an ideally rigid draw-die construction, nevertheless, may become questionable when it comes to the forming of high strength steels due to the higher forming loads needed. in addition, a side trust is generated in the forming of large-scale structural parts with non-symmetric profiles, which may apply remarkably high loads on the balancer blocks and on the wear plates between the punch and binder elements increasing the wear and distortion of guideposts. in these cases the deformations of the production tooling should be included in the computational modeling of the forming process. presently, build-ing a computer model in order to simulate the complete process system is achievable considering the advancements in computer hardware and finite element software, noneth-eless it is hardly feasible from an industrial perspective due to the high computer analysis times. instead a rather simple but a practical engineering approach may be the decoupling the stamping system in to the process-only part composed of the blank plus the die-face design and tooling-only part containing complete draw-die design, based on the individual characteristics of the deformations experienced during a complete pressingcycle, respecti-vely. considering process-only part, there are time-dependent interactions of the sheet met-al blank and the forming interface bringing about large changes in the blank shape when compared with the scale of die-face distortions. consequently, the process-only part should be simulated using a finite element formulation based on large-strain and finite incremental deformation theory due to the kinematic characteristics of the blank deformations 8. on the other hand,small deformation transientssuperimposed on to the large displacements histories characterize the deformations of the draw-die elements during a single forming cycle. therefore, a small strain elasticplastic finite element analysis of the draw-die construction may be appropriate. the interaction of both computational sides is defined in terms of an appropriate data transfer routines (fig. 1). for the process-only part, the forming simulation uses the geometry information from die-face design as rigid surface entities and the blank as an elasticplastic deforming body, and the time-dependent disp-lacement-driven binder and punch motion realize the forming process. the major outputs are deformed geometry and production stress distributions of the blank after springback and the forming load histories as well as the frictional contact stress distributions over the die-face elements. on the other side, for the tooling-only part, the forming load histories are the basic input for the assessment of the die-face deformation analysis. the finite ele-ment analysis of the complete draw-die design for a given press cycle provides the displace-ments of dieface material points, and the updated die-face design may be fed back to process-only part for the next iteration. also the computed elasticplastic stressstrain histo-ries during a complete press cycle and the contact forces between the punch and binder elements through the wear plates and balancer blocks bring about a significant insight to the interaction of draw-die construction elements.4. industrial applicationthe engineering methodology outlined in the previous section is employed in the structural assessment for the stamping die design of a front-side cab body member before the tooling production (fig. 2). the strength of this part is an essential feature in the crash-energy management of a cab frame. the conventional design practice for this type of large-scale structural elements is to use draw-quality steels of thickness 1.72.2 mm. the commercial availability of 1.5 mm hsla steel with a higher yield stress and moderate level formability 1,3 introduced as a feasible alternative with enhanced strength propert-ies along with an approximately 1015% weight reduction.the forming process design of the part stamping form is done following a pure geometric modeling approach, and all die-face deformations are neglected assuming a rigid stamping tooling. using the 3-d cad model of the part, firstly an undercut check is conducted in order to determine the possibility of forming the part in a single operat-ion.subsequent to the investigation of the tip angles for the part, the 3-d part geometry is rotated to the configuration of the ram motion direction, so that the part is positioned appropriately in the press coordinate system in which the pressing-axis became parallel to the part-drawing axis(fig. 3). using the 3-d cad model of the part, a set of surfacesfor the upper die geometry is generated with an offset equal to the half of the sheet metal thickness, and a set of addendum areas are added to this set of surface geometries.since the part sidelines follow a curved form, the extended surface geometry follows approximately a similar form, and therefore a sweep binder surfaces and addendum flange