Blank Optimization Research Articles

Deformation Characteristics and Microstructure Analysis of Aluminum Alloy Component with Complex Shape by Cold Orbital Forming

This work aimed to study the deformation characteristics and microstructure of AA6063 aluminum alloy component with complex shape manufactured by cold orbital forming processing. The material flowing behavior was analyzed by Finite Element (FE) simulation and forming experiments were carried out using bar blank with different lengths. The microstructure of the boss zone cut from the formed samples was observed using scanning electron microscopy (SEM) and electron back-scatter diffraction (EBSD). FE simulation and experiment results both showed the aluminum base can be formed using cold orbital forming process. The distributions of the effective strain of the component with different blank lengths were almost the same, and the effective strain was bigger at the boss and the flash as the forming finished. The material flow is complex, especially in the boss, and the folding defect was observed at the root of the boss. The distribution of Mg2Si strengthening precipitate is more homogeneous in the matrix, has a different shape, and shows directivity at different position of boss zone. The grains are elongated, and the extent is different at different positions of the boss zone after cold orbital forming, and the crystal orientation discrepancy is smaller in the component main body and bigger in the boss zone. Subsequent forming process and blank optimization need to be further researched to improve forming quality.

Blank shape optimization in the deep drawing process by sun method

Deep drawing is one of the most important and widely used processes in industry for the production of various parts. In this process, the optimal design of the blank has many advantages such as reducing the cost of production and waste and improving the quality of the process and thickness distribution. In this study, blank optimization involves finding an initial blank geometry in which the edge contours of the final product approach a target contour, taking the required shape after deep drawing. A new iteration based method is proposing for optimizing the shape of a blank in the deep drawing process. The behavior in such problems is severely nonlinear as a result of major plastic deformations and contact phenomena. The general solution to such problems has been to use numerical simulation iterative based methods. The present study implements a similar approach and presents a new algorithm to make geometrical corrections to the external boundaries of a blank in several iterations. A computer program was developed to automatically run these iterations to study the features of the proposed method. Next, two numerical example was solved, and the results are compared with other studies. The proposed method is robust against the initial guess as it manages to optimize the blank regardless of it.

Research on Blank Optimization Design Based on Low-Carbon and Low-Cost Blank Process Route Optimization Model

The optimization of blank design is the key to the implementation of a green innovation strategy. The process of blank design determines more than 80% of resource consumption and environmental emissions during the blank processing. Unfortunately, the traditional blank design method based on function and quality is not suitable for today’s sustainable development concept. In order to solve this problem, a research method of blank design optimization based on a low-carbon and low-cost process route optimization is proposed. Aiming at the processing characteristics of complex box type blank parts, the concept of the workstep element is proposed to represent the characteristics of machining parts, a low-carbon and low-cost multi-objective optimization model is established, and relevant constraints are set up. In addition, an intelligent generation algorithm of a working step chain is proposed, and combined with a particle swarm optimization algorithm to solve the optimization model. Finally, the feasibility and practicability of the method are verified by taking the processing of the blank of an emulsion box as an example. The data comparison shows that the comprehensive performance of the low-carbon and low-cost multi-objective optimization is the best, which meets the requirements of low-carbon processing, low-cost, and sustainable production.

A blank optimization by effective reverse engineering and metal forming analysis

Finite element methods help us to better understand the complex plastic deformation behaviour of sheet metal component during forming. The present work aim is to optimizing blank sheet of existing dimension 1535 X 1600 X 1.2 mm of a commercial vehicle component of engine tunnel bottom has to optimize by using finite element simulation without compromising safety and quality. A reverse engineering technology has been adopted for generating the CAD data of the forming tools. The forming simulation is carried out by using a commercially available explicit solver based software PAMSTAMP. While trying the reduced blank width, the blank holder force had been increased by about 15% (from the existing force 350kN to 400kN). The simulation results of the optimized blank sheet have been compared with the existing blank, which ensure the optimized blank is suitable for the engine tunnel bottom component without creating any defects and failures. Finite element method in sheet metal forming application have always helped us in weight savings and cost saving of automotive components.

Topology optimization of blank holders based on a kriging-interpolated level-set method

ABSTRACT Blank holders play an important role in non-isothermal stamping, and blank holder optimization is thus investigated in this article. A kriging-interpolated level-set method based on a parallel infilling strategy is proposed. First, a new method is used to discretize the design domain of a blank holder. The first-stage kriging model between the nodes and level-set values is developed, and a new blank holder structure can be determined according to a level-set threshold. The second-stage kriging model between the level sets and forming quality is then developed. The second-stage kriging model is updated based on a parallel infilling strategy. The best level-set values are obtained via an improved particle swarm optimization, and the optimal blank holder structure is determined. The proposed method is validated using a cross-shaped part. The results show that the optimized blank holder mass is reduced by 28%, and the forming quality is improved significantly.

Optimization of Initial Blank Shape for Minimizing the Trimming Process in Hot Stamping of T-Shaped Parts

Blank optimization in stamping is a way to reduce the cost of unnecessary material consumption or subsequent trimming operations by acquiring the final target part in a single forming process. There have been many studies on blank optimization in room temperature stamping, but few studies have yet been conducted in hot stamping. In this study, a blank shape optimization was conducted for a T-shaped part simulating a body center pillar. A finite element analysis (FEA) for the hot stamping process was performed using an appropriately assumed initial blank shape, and the blank shape was updated based on the shape error between the outline of the deformed blank obtained from the FEA and that of the target part. The shape error was calculated by applying the modified radius vector method. Hot stamping test was carried out using the optimal shaped blank predicted by the FEA. It was confirmed that the outline of the deformed blank obtained by the actual test was very close to the outline of the target part. From the results of this study, it can be seen that the blank optimum design technique at room temperature stamping can be applied to the case in hot stamping.

Initial Blank Optimization Design of Square Can Multistage Drawing considering Formability and Product Shape

Initial Blank Optimization Design of Square Can Multistage Drawing considering Formability and Product Shape

타원형 다단 딥 드로잉 제품의 성형성 향상을 위한 초기 소재 형상 최적 설계

다단계 딥 드로잉(multi-stage deep drawing)은 산업현장에서 대형의 금속 제품 뿐만 아니라 소형의 제품에 까지 많은 제품으로 확대되고 있는 제조 공정 중 하나이다. 예를 들어, 스마트 폰에 사용되는 USB-C형 소켓은 매우 작고, 정밀하며 세장비가 큰 부품이며, 이 제품은 타원형 다단계 딥드로잉 방법으로 제조된다. 다단계 딥 드로잉에 최종 제품의 두께 분포를 보장하기 위해서 다단계 딥드로잉 전체 공정에서 제품의 두께 분포가 균일하게 유지되어야 한다. 따라서 첫 번째 드로잉 작업 후에 타원형 제품의 장변과 단변쪽 측벽의 높이 차를 최소화하는 것은 최종 제품의 균일한 두께를 보장하는 가장 중요한 공정 설계 인자이다. 본 연구에서는 첫 번째 드로잉 공정 후 소재가 균일한 높이를 지속적으로 유지될 수 있도록 하기 위해서 유한요소해석을 기반으로 초기의 타원형 소재 형상 결정에 대한 최적 설계를 수행하였다. 최적 설계된 초기 블랭크 형상으로 성형된 제품의 경우 전체 균일한 두께 분포를 가질 뿐만 아니라 드로잉 후 제품의 장변과 단변의 높이 단차가 최소화 되었다. 최종적으로 최적 설계로 예측된 초기 소재 형상은 실제 실험 결과와 비교하여 검증되었고, 매우 양호한 결과의 일치를 보여주었다. Multi-stage deep drawing is a widely used industrial manufacturing process, and its applications are gradually expanding to both small products and large metallic products. The USB C-type socket used in smart phones, for example, is manufactured using oval multi-stage deep drawing. The socket is very small and slender and it requires precise manufacturing. The thickness distribution of the final product is guaranteed only if it is uniform throughout the overall process. Therefore, minimizing the height difference between long and short sidewalls after the first operation is important for this goal. An initial blank optimization was performed for an oval-type drawing process based on finite element simulations. The goal was to determine an initial blank geometry that can maintain uniform height and thickness after the first draw operation. The initial blank shape of the sheet metal was optimized, and the results show that it satisfied the conditions of minimal thickness reduction and even thickness distribution. The geometry from the optimized simulation was compared with experimental results, which showed good agreement.

A blank optimization design method for three-roll cross rolling of complex-groove and small-hole ring

Complex-groove and small-hole rings have the common geometric characteristic of asymmetric deep-groove on the outer surface and small-hole in the center, such as duplicate gears and double-side flanges. It is difficult to get the complete section profile directly by traditional forging or special ring rolling technology. Three-roll cross rolling (TRCR) is an advanced plastic deformation to form ring parts with deep groove, which can form the complete deep groove directly by three-roll rotary rolling. As a key to the design of TRCR, the blank design influences material flow and distribution as well as final shape of deep-groove. In this paper, the material flow behavior in TRCR of complex-groove and small-hole ring with rectangular section blank is analyzed by a theoretical approach. Through analysis, forming the ring with stepped-section blank is put forward, and a theoretical method to design the blank size is established. Then the possibility and shortage of the theoretical method are discussed by FE simulation. Therefore, a volume correction coefficient is proposed to correct the blank size. Further, a prediction model of the volume correction coefficient is established by using orthogonal simulation test and back propagation (BP) neural network. Finally, the blank design method is verified by simulation and experiment. The result shows that complex-groove and small-hole rings can be formed perfectly with blanks which are designed by the theoretical formulas and the prediction model.

Simulation of Automotive Galvanized Steel Stamped Parts: Experimental and Numerical Approach

In the rapid new automobile development, the use of simulation technology is highly demanded due to shorter time to market and fashionable product styling that go beyond the rule-of-thumb in the manufacturing technology. In stamping simulation, the expected predictions rest with the part formability, spring back, blank optimization, and other vehicle integration works. These predictions are conducted concurrently during detailed product design, and intensive product validation is performed based on such predictions. In current work, it has established the experimental mechanical properties and flow curve data for thin galvanized sheet metal. Furthermore, the true prediction of part formability is investigated with established data and standard material database embedded in commercial simulation software. The tensile experiments were carried out on a uniaxial hydraulic tensile test machine with sheet metal specimen and in accordance to ASTM requirements. Three different sheet metal specimens were prepared from the longitudinal, transverse and 450degrees from the rolling direction. From experimental works and formulation, the mechanical properties, anisotropy and flow curve had been obtained. Further improvement in the embedded material database increases the prediction accuracy of FEM analysis for Body-in-White structure and crash performance.

Blank optimization for free bulging of Inconel 718 to maximize bulged height at high temperatures

Thickness profiled blank is designed via the optimization technique to maximize the bulged height in free bulging for Inconel 718. The thickness of the blank is described by the Bezier curve by using four control points. The location of each control points is used for the design variables of optimization. The material parameters for the flow stress equation of Inconel 718 are obtained from the free bulging test at constant pressure condition by using a flat blank and verified via numerical analysis. The objective function and constraints for optimization are the maximization of the bulged height within a limited strain range. The equivalent static load method for non-linear static response structural optimization with a move limit scheme is used for optimization. The result of optimization shows 21.95% increased bulged height and uniformly distributed strain after bulging. The free bulging test using blank with optimized profile is conducted to verify the optimization process. The results of bulged height and deformed shape are compared with those from numerical analysis, and the comparison shows good agreement.

Design of Multi Band Rectenna using Blank Box Optimization Technique

As we all know that demand of energy is increasing day by day. We all are surrounded by the Radio Frequency waves, so the harvesting of radio waves for our energy requirements could be the alternative source of energy. Rectenna is a device that is used to convert RF Energy into DC power. Rectenna is designed using triangular microstrip patch antenna TMPA. The main motive behind this is to have battery free devices. This thing will also help us to protect our nature from harmful chemicals like cadmium, mercury etc. that are used in batteries This paper is concerned with the study design, analysis and fabrication of multi band Rectenna so that it can be used at various frequencies. We have used the blank box optimization technique in order to get enhanced bandwidth, gain, Return Loss and efficiency.

The Blank Optimization of an Automotive Fender Skirt in the Process of Sheet Metal-Forming Based on one-Step Simulation Method

This article puts forward One-step forming simulation method to solve blank outline problems in the process of sheet metal forming. The blank outline curve is got from the simulated analysis of Groupware of Fender by one-step simulation in Dynaform 3D software for sheet forming, considering the final shape of the workpiece. It simulates three programs via three different shapes of blanks. And it compares and analyze the FLD diagram and forming results ,and then it gets the optimized blank shape. This way guides the mould design, and save the time of repairing moulds on the basis of producing qualified products. It overcomes the puzzle how to choose the blanks’ size and shape.

Blank optimization in a stamping process—Influence of the geometry definition

Nowadays initial geometry optimization methods are increasingly being adopted in order to solve complex mechanical plastic forming processes. This kind of approach can focus, in estimating the initial shape of a certain metallic specimen (or blank) in order to achieve a desired geometry after forming. In the present work the superplastic forming of a carter is described and studied in detail. After plastic forming it is possible to verify an undesirable non-homogeneous thickness distribution in the final geometry. A non-uniform thickness distribution of the initial blank can be proposed in order to obtain a regular final thickness of the sheet and avoid this problem. In the present paper the blank surface is modeled by means of a non-uniform rational B-spline (NURBS) surface, where the coordinates of specific NURBS control net vertices are chosen to be the optimization variables. The optimization procedure is carried out by combining a finite element (FE) software and a suitable optimization code. Four different studies were performed, differing in the number of control vertices that formulates the NURBS surface (16, 25, 36 and 49 control vertices were considered), in order to study the influence of the initial geometry definition. A geometry definition leading to better results is achieved, considering both computational cost and final result precision, and subsequent discussions are carried out.

A comparison of numerical iteration based algorithms in blank optimization

Different approaches for blank shape optimization are reported in the literature. These include numerical iteration based algorithms, slip line field and inverse approach methods and so on. Some iteration based algorithms are reported in the literature. However a comparison of these methods can provide a useful guide regarding their efficiency. In this paper, a new iteration based method for blank shape optimization is presented. Also two other iteration based algorithms reported in the literature are described briefly. The optimum blank shapes for some case studies are obtained using each algorithm and the results are compared. The results indicate that the algorithm developed in the current work is more efficient.

Blank Shape Optimization of Square Cup Deep-Drawing under the Unilateral Constrained Condition

To satisfy the forming need of single-basin with a flange, sensitivity analysis is used to optimize the shape on the basis of the initial shape which gotten by the backward simulation method of analysis software ETA/Dynaform5.5.The optimum blank shape for unilateral constrained square cup deep-drawing is determined, and the optimized results were analyzed and compared before and after. Some measures about blank optimization will be given to such parts.

Blank Optimization in Elliptical-Shape Sheet Metal Forming Using Response Surface Model Coupled with Reduced Basis Technique and Finite Element Analysis

The present study aims to determine the optimum blank shape design for the deep drawing of Elliptical-shape cups with a uniform trimming allowance at the flange i.e. cups without ears. This earing defect is caused by planar anisotropy in the sheet and the friction between the blank and punch/die. In this research, a new method for optimum blank shape design using finite element analysis has been proposed. Present study describes the approach of applying Response Surface Methodology (RSM) with Reduced Basis Technique (RBT) to assist engineers in the blank optimization in sheet metal forming. The primary objective of the method is to reduce the enormous number of design variables required to define the blank shape. RBT is a weighted combination of several basis shapes. The aim of the method is to find the best combination using the weights for each blank shape as the design variables. A multi-level design process is developed to find suitable basis shapes or trial shapes at each level that can be used in the reduced basis technique. Each level is treated as a separated optimization problem until the required objective – minimum earing function – is achieved. The experimental design of RSM method is used to build the approximation model and to perform optimization. MATLAB software has been used for building RSM model. Explicit non-linear finite element (FE) Code Abaqus/CAE is used to simulate the deep drawing process. FE models are constructed incorporating the exact physical conditions of the process such as tooling design like die profile radius, punch corner radius, etc., material used, coefficient of friction, punch speed and blank holder force. The material used for the analysis is Stainless steel St12. A quantitative earing function is defined to measure the amount of earing and to compare the deformed shape and target shape set for each stage of the analysis. The cycle is repeated until the converged results are achieved. This iterative design process leads to optimal blank shape. So through the investigation the proposed method of optimal blank design is found to be very effective in the deep drawing process and can be further applied to other stamping applications.

Blank Optimization of Sheet Metal Forming Based on Response Surface Methodology

The thickness variation of drawing part is usually very complicated, which causes the accurate calculation of the surface area of drawing part to be very difficult. Blank optimization of sheet metal forming is often considered as a multi-objective problem. A blank optimization strategy of sheet metal forming process was suggested based on Response Surface Methodology (RSM). Latin Hypercube Sampling (LHS) method was introduced to design the rational experimental samples; the objective function was defined based on crack factor and wrinkle factor; the accurate response surface for sheet metal forming problem was built by Least Square Method; Genetic Algorithm (GA) was adopted in optimization and Pareto solution was selected. The strategy was applied in blank optimization of an auto-part, this method was proved suitable for blank optimization of sheet metal forming.

Novel approach to initial blank design in deep drawing using artificial neural network

In the deep drawing process, the initial blank has a simple shape but its perimeter shape becomes very complex after drawing. If the initial blank shape is designed in such a way that it is formed directly into the desired shape by the drawing process, this will lead to a reduction in the trimming process and a decrease in the drawing force and raw material. The present paper proposes a novel approach to the initial blank optimization in deep drawing by using an artificial neural network (ANN) to obtain the shape of the initial blank in one step. The finite element method (FEM) is employed for simulating the deep drawing process to provide training data for the ANN. The aim of the neural network is to predict the initial blank shape for the desired final shape. Results from sensitivity analysis and experimental tests were compared. The FEM results were verified through experiment.

Application of Blank Optimization Method in Deep Drawing of Rectangular Magnesium Alloy Cups under Non-Isothermal Condition

Using the optimum blank in sheet metal forming process not only can decrease the material wasting but also avoid possible defects such as local severe thinning, wrinkling and fracture. Since it is practical technology for industrial production, many blank optimization methods have been proposed and their validity was verified by some forming tests of typical or complicated components. However, all the forming tests were carried out at room temperature or under isothermal condition. In present work, a blank optimization method was employed to evaluate its efficiency in deep drawing of rectangular magnesium alloy cups under non-isothermal condition. It is proved by experiment that the employed blank optimization method can predict successfully the optimum initial blank shape for the component with specified shape and dimension.