Springback and Side Wall Curl of Metal Sheet in Plain Strain Deep Drawing (original) (raw)
Related papers
Literature Review on Analysis of Spring Back in Sheet Metal Forming Processes
International Journal for Research in Applied Science & Engineering Technology (IJRASET), 2022
The spring back is the part of sheet metal bending that is most susceptible to failure during unbounding. Elastic and plastic deformation combine to completely distort the workpiece (sheet metal) during the metalworking process. When sheet metal is being worked on, it is put under a lot of pressure, which causes plastic deformation. However, when the pressure is released, the material recovers elastically. During the entire process. small amount of reduction in the total deformation takes place So, this phenomenon. is called as spring back-the change in sheet metal's geometry. The thickness of sheet metal ranges from 0.5 mm to 6 mm. Depending on the tooling geometry, material qualities, sheet thickness, and punch and die properties, spring back can affect the completed part's dimensional accuracy. Sheet metal elements / materials / appliances made in industries such as automotive OEM and ancillaries, enclosures aircraft, heavy machinery, medical devices etc. are affected by spring back in their correctness. This review study examines various factors influencing springback in sheet metal fabrication
MATEC Web of Conferences
The process of sheet metal forming is one of the very important processes in manufacture of products mainly in the automotive field. In sheet metal forming, it is added a certain size at the die to tolerate a result of the elasticity restoration of material. Therefore, when the product is removed from the die then the process elastic recovery will end within the allowable tolerance size. Extra size of the die is one method to compensate for springback. The aim of this research is to optimize the die by entering a springback value in die design to improve product quality that is associated with accuracy the final size of the product. Simulation processes using AutoForm software are conducted to determine the optimal parameters to be used in the forming process. Variations the Blank Holder Force of 77 N, 97 N, and 117 N are applied to the plate material. The Blank Holder Force application higher than 97 N cannot be conducted because the Forming Limit Diagram indicates the risk of tearing. Then the Blank Holder Force of 37 N, 57 N and 77 N are selected and applied in cup drawing process. Even though a few of wrinkling are appear, however there is no significant deviation of dimension between the product and the design of cup.
Study the Effects of Spring Back on Sheet Metal Bending using Mathematical Methods
Journal of Material Science & Engineering, 2017
In this study mathematical analysis of spring back was done for optimization of sheet metal bending process. The influence of sheet metal thickness, sheet metal type, friction, tool radius and tool shape on spring back for Aluminium, copper, mild steel and High strength steels, sheet metal have been used as variable to conducted this study. Since, the effects of each variable on the formation of spring back on sheet metal forming are investigated the following way. This empirical result shows that increasing sheet metal thickness from 0.8 mm to 4.5 mm the spring back is reduced 16% and 20.35%. When increasing of sheet metal strength spring back increases because spring back of the sheet should depend on the yield strength of the material. As the materials yield strength increase the spring back after unloading condition also increases. The effects of material type as shows that, using Aluminium sheet metal instead of high strength sheet metals spring back is reduced by 56.%. Also, for decreasing of the tool radius leads reducing spring back. Spring back of deferential die 12% lower than edge bending die. In addition to these, if increasing the friction coefficient from 0.01 to 0.50 the spring back also increases by 52% because of increasing of friction force and this force generates higher amount of spring back. Thus the effects of material type, tool geometry, working condition and the thickness of sheet metal types were studied and investigated. Since, ultimately utilizing and compensation of tool is considered for prevention of spring back and optimizing of sheet metal bending process as well.
Examination of Springback in Sheet Metal Forming by Finite Element Method
2014
Sheet metal deformation is widely used in automotive industry. Nowadays the automakers try to reduce the weight of the cars by using high strength steel. The disadvantage of the high strength steel is its significant springback effect. One of the aims of this study is to utilize the springback compensation algorithm of the commercial software during the drawing simulation process. In this paper, we discuss how the sheet metal deformation was simulated by using DYNAFORM V5.5 software. The results of the simulations were compared with producers’ experience. The geometrical data of the simulated parts were provided in “.iges” file format by producers of machine components. The model prepared for the simulation was developed as a system of die, punch, addendum, binder, and blank. After sheet plastic forming analysis was done, springback was performed. LS-DYNA software was used as a solver in the simulations.
Spring back is the main defect in sheet metal bending process. The spring back of sheet metal bending, which is defined as elastic recovery of the part during un loading conditions. It should be taken in to considerations so as to produce bent sheet metal parts within acceptable quality. Spring back is affected by the factors such as; sheet thickness, tooling geometry, friction condition; material property and processing parameters. In this research the numerical investigation of Spring back on edge bending die process is done.. The numerical Analysis is done using ANSYS LS-DYNA. The influence of sheet metal thickness, sheet metal type, friction, tool radius and tool shape on spring back for Aluminium, copper, mild steel and High strength steels, sheet metal have been considered for investigations. Abstract-Spring back is the main defect in sheet metal bending process. The spring back of sheet metal bending, which is defined as elastic recovery of the part during un loading conditions. It should be taken in to considerations so as to produce bent sheet metal parts within acceptable quality. Spring back is affected by the factors such as; sheet thickness, tooling geometry, friction condition; material property and processing parameters. In this research the numerical investigation of Spring back on edge bending die process is done.. The numerical Analysis is done using ANSYS LS-DYNA. The influence of sheet metal thickness, sheet metal type, friction, tool radius and tool shape on spring back for Aluminium, copper, mild steel and High strength steels, sheet metal have been considered for investigations.
Numerical Investigation of Spring Back on Sheet Metal Bending Process
Spring back is the main defect in sheet metal bending process. The spring back of sheet metal bending, which is defined as elastic recovery of the part during un loading conditions. It should be taken in to considerations so as to produce bent sheet metal parts within acceptable quality. Spring back is affected by the factors such as; sheet thickness, tooling geometry, friction condition; material property and processing parameters. In this research the numerical investigation of Spring back on edge bending die process is done.. The numerical Analysis is done using ANSYS LS-DYNA. The influence of sheet metal thickness, sheet metal type, friction, tool radius and tool shape on spring back for Aluminium, copper, mild steel and High strength steels, sheet metal have been considered for investigations.
Springback in plane strain stretch/draw sheet forming
International Journal of Mechanical Sciences, 1995
Accurate prediction of springback is essential for the design of tools used in automotive sheet stamping operations. The plane strain stretch/draw operation presents a complex form of springbaek occurring in sheet metal forming since the sheet undergoes stretching, bending and unbending deformations. The two-dimensional draw bending is an example of such an operation in which the complex stress-strain states in the sheet cause the formation of side wall curls after the sheet is allowed to unload. Accurate prediction of the side wall curl requires using finite element shell models which can account for curvature and through-thickness stresses caused by bending and unbending of the sheet. Since such models are generally slow and expensive to use, an alternative and efficient method of predicting side wall curls will be desirable. This paper describes a novel and robust method for predicting springback in general and side wall curls in the two-dimensional draw bending operation as a special case, using moment-curvature relationships derived for sheets undergoing plane strain stretching, bending and unbending deformations. This model modifies a membrane finite element solution to calculate through-thickness strains and stresses and springback. Accuracy of this model's predictions are verified by comparisons with finite element (ABAQUS) and experimental results. x,y Z C R k n K t W 0, g (7 v r E T M Subscripts C n B UB 0 T mem
International Journal of Mechanical Sciences, 2008
This paper presents the results obtained from a series of experiments on double-curvature forming of 300 mm square and 15 mm thick plates of type 316L(N) stainless steel to evaluate the inherent springback and also to validate finite element method (FEM) based process model developed for forming of multiple-curvature sectors of large size vessels. The experimental results show that twisting of the plate occurs during pressing, which is unavoidable in an actual forming setup on the shop floor. Twisting increases with increase in slope of the die cavity. Springback in the plate changes in an ascending order towards the centerline of the plate from the edges. The final radius of curvature (ROC) on the pressed plate after springback does not remain constant along a particular axis although the die and the punch had constant ROC along that axis because of varying constraint to opening up of the plate from centerlines to the edges. Springback also increases with reduction in the stiffness of the die and punch. The simulated plate profiles obtained from the FEM process model for multiple-curvature plate forming compared well with the experiments, the maximum error being within 6%. The process model used a sequential dynamic explicit formulation for the plate pressing phase and a static implicit formulation for the unloading (springback) phase in the Lagrangian framework. Reduced integration shell elements were used for the plate and the die and the punch were considered rigid. Dynamic explicit FEM for pressing and static implicit FEM for the unloading phase are adequate and economic for modeling of plate forming process by using FEM. The necessary material and frictional property data needed for the FEM process model were generated in-house. This model can be applied to design of dies and punches for forming the petals of large pressure vessels. The FEM process model predicts the final shape of the product and the residual cold work level for a given die, punch and plate configuration and this information can be used to correct the die and punch shapes for springback to manufacture the petals to the desired accuracy. r
The influence of process conditions on springback in bending process
-In the sheet metal forming process, the steel, in this case deep drawing quality steel DC06 exhibits springback effect, which is governed by strain recovery of material after the load removal. In this work, numerical simulation of a V-shape part bending was performed and compared with experimental data. Springback is related to many parameters like forming conditions, tool geometry and material properties such as sheet thickness, yield stress, work hardening, strain rate sensitivity and elasticity modulus. In this contribution, the influence of process conditions on springback effect of V-shaped part made of deep drawing quality steel DC06 was investigated. In the numerical simulation, two types of Yield criterion: Hill48 and Barlat were used in combination with Swift hardening model. Achieved data from numerical simulation were compared with experimental test results.
Journal of Mechanical Engineering and Sciences, 2015
This paper focuses on the effect of the die and punch radii on the springback in the air V-die free bending process of stainless steel sheet metal. The experiment was performed on sheet metal using various die and punch radius values while their springback behavior was observed. The design of experiment approach was used in these experiments using the full factorial and analysis of variance methods to identify whether or not the die and punch radii are significant input parameters in predicting springback. From the statistical analysis, it shows that the die and punch radius parameters are significant factors contributing to the springback effect in the V-die bending of stainless steel sheet metal at the significance level of 0.05 because their p value is less than 0.05. The results from the experiments showed that springback is affected by the die and punch radius values in the air V-bending experiments. From this analysis, it can be concluded that the springback values can be decreased by decreasing the values of the die and punch radii. In the air V-die bending process, the punch radius is the most important factor to be considered. The experimental method agreed well with the design of experiment results.