Deviations between FE Simulation and Experiments in the SPIF Process

2011 ◽  
Vol 473 ◽  
pp. 937-946
Author(s):  
Ioannis Vasilakos ◽  
Jun Gu ◽  
Hans Vanhove ◽  
Hugo Sol ◽  
Joost R. Duflou
Keyword(s):  
Fe Simulation ◽  
Single Point ◽  
Model Identification ◽  
Material Model ◽  
Initial Guess ◽  
Inverse Methods ◽  
Material Behavior ◽  
Fe Model ◽  
Forming Process ◽  
Tool Set

Single Point Incremental Forming (SPIF) is a modern and flexible alternative to traditional forming techniques. It thanks its flexibility to the fact that it does not require a dedicated tool set to operate. Numerical simulation of the SPIF process requires an accurate FE model. In the past several attempts have been undertaken to use inverse methods for sheet metal SPIF material model identification based on shearing, tensile and indenting tests. The basic idea of this paper is that the results of inverse methods can be improved by using the SPIF process itself as experimental data source. A SPIF experiment dedicated for material identification on a simple geometry using large step sizes is presented and compared with the FE simulation of the forming process based on an initial guess for the material behavior.

Investigations on Three-Roll Bending of Plain Tubular Components

2009 ◽  
Vol 410-411 ◽  
pp. 325-334 ◽  
Author(s):  
Marion Merklein ◽  
Hinnerk Hagenah ◽  
Massimo Cojutti
Keyword(s):  
Material Behavior ◽  
Fe Model ◽  
Forming Process ◽  
Widespread Application ◽  
Numerical Investigations ◽  
Industrial Sectors ◽  
Roll Bending ◽  
First Results ◽  
Bending Radius ◽  
High Flexibility

Bent metal tubes find a widespread application in many industrial sectors. Among different bending processes developed for the manufacturing of these components, three-roll bending is characterized by a high flexibility, as only one toolkit per tube diameter is necessary to form the required bending radius. In this type of forming process the part geometry is obtained by means of a relative movement of the die (setting roll) towards the fixed tools (bending and holding roll) with simultaneous feeding of the tube. This study describes the FE-model developed for the three-roll bending and presents first results of numerical investigations conducted on steel tubes made of carbon steel St37. By the FE-analysis great attention is paid on the modeling of the stiffness of the tool, on the description of the kinematics of the setting roll as well as on the characterization of the material behavior for the simulation. The results of the numerical investigations are compared with experiments conducted with a CNC-bending machine available at the Chair of Manufacturing Technology of the University of Erlangen. As a main criterion for the validation of the FE-model the radius of the tube at the extrados and the bending angle are chosen. The geometry of the part is measured by means of both optical and tactile measuring devices.

Drilled Hole Technique for Created Single Point Incremental Forming Limited Diagram

2015 ◽  
Vol 658 ◽  
pp. 177-181
Author(s):  
Kittiphat Rattanachan
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Single Point ◽  
Material Behavior ◽  
304 Stainless Steel ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Steel Blank ◽  
Etching Technique ◽  
Drilling Hole

To produce the forming limited diagram for predicting and studying material behavior in sheet metal forming, grid etching or grid marking on blank surface are applied before forming. But in single point incremental forming process, sheet metal blanks are subjected to highly strain or highly deformation which the conventional gridding is no longer to be occurred on the surface of formed part. And some material such as titanium, nickel based alloy etc are difficulty to etch the grid marks on its surface. So this paper is proposed the drilling hole technique to substitute with the grid etching technique in single point incremental forming process. The holes 2 mm. diameter were drilled on the SUS 304 stainless steel blank before forming. The deformed holes are calculated as true major strain and true minor strain and plot into a forming limited diagram. The results are compared with the conventional etching techniques which show an according trend. The drilling hole technique could be used in study the material behavior in single point incremental forming, it a low cost convenient and easy than grid etching technique.

A Modified Shell Element Model Combined with Yld91 Yield Function in Simulating Aluminum Alloy Applied Hydroforming

2015 ◽  
Vol 639 ◽  
pp. 435-442 ◽  
Author(s):  
Fei Fei Zhang ◽  
Jun Chen ◽  
Jie Shi Chen ◽  
Xin Hai Zhu ◽  
Shi Jian Yuan
Keyword(s):  
Normal Stress ◽  
Fe Simulation ◽  
Applied Pressure ◽  
Shell Element ◽  
Material Model ◽  
Element Model ◽  
Yield Function ◽  
Element Formulation ◽  
Thickness Direction ◽  
Forming Process

Hydroforming has been used widely across many industrial fields. Large applied pressure during hydroforming makes it necessary to consider the influence of normal stress in the thickness direction, while in FE simulation, the use of traditional shell element based upon plane-stress assumption is not appropriate in such cases. Here, the traditional shell element is modified by changing the constitutive relation which took into account the normal stress in the thickness direction, and the modified shell element formula is combined with Yld91 yield function to simulate the forming process of Aluminium alloy. Then the element formulation and material model is implemented into the FE code Ls-Dyna by means of USER interface. Two examples are carried out and good correlations are obtained when compared to the traditional shell element and solid element.

A Study of Single Point Incremental Forming by Finite Element Analysis

2014 ◽  
Vol 657 ◽  
pp. 163-167 ◽  
Author(s):  
Khalil Ibrahim Abass
Keyword(s):  
Boundary Conditions ◽  
Incremental Forming ◽  
Single Point ◽  
Material Behavior ◽  
Complex Nature ◽  
Process Conditions ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Element Analysis ◽  
Highly Nonlinear

The Single Point Incremental Forming Process (SPIF) involves extensive plastic deformation. The description of the process is more complicated by highly nonlinear boundary conditions, namely contact and frictional effects have been accomplished. The SPIF analysis is mathematically complex. However, due to the complex nature of these models, numerical approaches dominated by the FEA are now in widespread use. The paper presents the data and main results of a study on SPIF through FEA, that permits the modeling of complex geometries, boundary conditions and material behavior. SPIF have been studied under certain process conditions referring to the test workpiece, tool, etc., using ANSYS 11.0. An important result is showing that the model of simulation can give as clearly the behavior of contact tool - workpiece and the effect it on strain and stress distributions, also on the accuracy of product. Relevant dependences between tool and workpiece surface interface and sample of results have been demonstrated.

Tensile Behavior of 82/182 Filler, Butter and Heat-Affected-Zones in a 508 LAS - 316 SS Dissimilar Weld: Tensile Test, Material Model and Finite Element Model Validation

2019 ◽  
Author(s):  
Subhasish Mohanty ◽  
Joseph Listwan ◽  
Saurindranath Majumdar ◽  
Krishnamurti Natesan
Keyword(s):  
Finite Element ◽  
Tensile Test ◽  
Low Cycle Fatigue ◽  
Material Model ◽  
Material Behavior ◽  
Test Material ◽  
Model Parameters ◽  
Fe Model ◽  
Component Level ◽  
Dissimilar Weld

Abstract In this paper we present the room temperature tensile test results for 82/182 Filler, Butter Weld and Heat-Affected-Zone in a 508 LAS − 316 SS Dissimilar Weld (DW). Also we present the associated tensile properties and material hardening model parameters; those can be used for future component level stress analysis modes. In addition, we present the finite element (FE) model of the uniaxial DW tensile-test specimens to validate the accuracy of the estimated material model parameters. Through the FE model results, we also explain the importance of various offset strain yield stress in capturing the material behavior in a mechanistic (using FE) modeling approach particularly while modeling the plasticity driven low-strain-amplitude low-cycle-fatigue damage of a structural component.

Texture Based Finite Element Simulation of a Two-Step Can Forming Process

2012 ◽  
Vol 504-506 ◽  
pp. 655-660 ◽  
Author(s):  
Vedran Glavas ◽  
Thomas Böhlke ◽  
Dominique Daniel ◽  
Christian Leppin
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Plastic Material ◽  
Large Strain ◽  
Material Model ◽  
Material Behavior ◽  
Flow Rule ◽  
Forming Process ◽  
Aluminum Sheets ◽  
Element Simulation

Aluminum sheets used for beverage cans show a significant anisotropic plastic material behavior in sheet metal forming operations. In a deep drawing process of cups this anisotropy leads to a non-uniform height, i.e., an earing profile. The prediction of this earing profiles is important for the optimization of the forming process. In most cases the earing behavior cannot be predicted precisely based on phenomenological material models. In the presented work a micromechanical, texture-based model is used to simulate the first two steps (cupping and redrawing) of a can forming process. The predictions of the earing profile after each step are compared to experimental data. The mechanical modeling is done with a large strain elastic visco-plastic crystal plasticity material model with Norton type flow rule for each crystal. The response of the polycrystal is approximated by a Taylor type homogenization scheme. The simulations are carried out in the framework of the finite element method. The shape of the earing profile from the finite element simulation is compared to experimental profiles.

scholarly journals Accuracy and Sheet Thinning Improvement of Deep Titanium Alloy Part with Warm Incremental Sheet-Forming Process

2021 ◽  
Vol 5 (4) ◽  
pp. 122
Author(s):  
Badreddine Saidi ◽  
Laurence Giraud Moreau ◽  
Abel Cherouat ◽  
Rachid Nasri
Keyword(s):  
Titanium Alloy ◽  
Titanium Alloys ◽  
Thickness Distribution ◽  
Single Point ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Fe Model ◽  
Forming Process ◽  
Shape Accuracy ◽  
Truncated Cone

Incremental forming is a recent forming process that allows a sheet to be locally deformed with a hemispherical tool in order to gradually shape it. Despite good lubrication between the sheet and the tip of the smooth hemisphere tool, ductility often occurs, limiting the formability of titanium alloys due to the geometrical inaccuracy of the parts and the inability to form parts with a large depth and wall angle. Several technical solutions are proposed in the literature to increase the working temperature, allowing improvement in the titanium alloys’ formability and reducing the sheet thinning, plastic instability, and failure localization. An experimental procedure and numerical simulation were performed in this study to improve the warm single-point incremental sheet forming of a deep truncated cone in Ti-6Al-4V titanium alloy based on the use of heating cartridges. The effect of the depth part (two experiments with a truncated cone having a depth of 40 and 60 mm) at hot temperature (440 °C) on the thickness distribution and sheet shape accuracy are performed. Results show that the formability is significantly improved with the heating to produce a deep part. Small errors are observed between experimental and theoretical profiles. Moreover, errors between experimental and numerical displacements are less than 6%, which shows that the Finite Element (FE) model gives accurate predictions for titanium alloy deep truncated cones.

Forming Margin Diagram for Tube Hydroforming with Radial Crushing under Linear Loading Path

2012 ◽  
Vol 538-541 ◽  
pp. 1106-1110 ◽  
Author(s):  
Zhi Hua Tao ◽  
Lian Fa Yang
Keyword(s):  
Fe Simulation ◽  
Tube Hydroforming ◽  
Loading Path ◽  
Fe Model ◽  
Forming Process ◽  
Loading Paths ◽  
Contour Lines ◽  
Working Status ◽  
Simulation Results ◽  
Linear Loading

Tube hydroforming with radial crushing (THFRC) process is one of tube hydroforming methods that is suitable for overlong structure parts forming process avoiding wrinkling and bursting failure. In this paper, the Forming Margin Diagram (FMD) for THFRC process was presented to optimize loading paths. Initially, parameters of Finite Element (FE) simulation in this study were represented, which contained FE model and linear loading paths. Afterwards, boundaries of the FMD were delimited based on real working status. Moreover, curves of corner radius, bursting failure and thickness uniform rate were determined by FE simulation results to establish the FMD, and the curves and zones on the FMD were analyzed simultaneously. Furthermore, features of contour lines were discussed, and the usage of the FMD was introduced.

Experimental and Numerical Examination on Formability and Microstructure of AA3003-H18 Alloy in Single Point Incremental Forming Process

2021 ◽  
Vol 904 ◽  
pp. 14-19
Author(s):  
Mohanraj Murugesan ◽  
Krishna Singh Bhandari ◽  
Jae Hag Hahn ◽  
Dong Won Jung
Keyword(s):  
Tensile Test ◽  
Material Properties ◽  
Computer Aided Design ◽  
Incremental Forming ◽  
Single Point ◽  
Rolling Direction ◽  
Fe Model ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Computer Aided

The single-point incremental forming process has witnessed significant advantages in automobiles, aerospace, and medical applications in recent years because of its flexibility in manufacturing complex shapes. In detail, the components are produced only using the toolpath, which is guided by computer-aided manufacturing software. However, during the forming process, the parts might experience fractures, which could heavily impact the formed part's geometric accuracy. The main purpose of this study is to analyze the formability of an AA3003-H18 aluminum alloy material in the SPIF process; for this purpose, the material properties are extracted from the experimental simple tensile test in three directions corresponding to the material rolling direction. At first, a simple tensile test is modeled and estimated the material properties for conducting the numerical simulations. Second, the real-time experiments of the SPIF process in terms of predefined forming conditions are performed, and then the surface roughness was measured to check the surface quality of the formed parts. Then, the formed parts are scanned using a 3D ATOS scanner and compared against the desired computer-aided design (CAD) model. Eventually, the numerical results are discussed in comparison with the experimental outcome and displayed a significant correlation toward the expected results. This results comparison communicates that the introduced finite element (FE) model can be adopted for investigating the appearance of thinning location, thinning reduction, distributions of stress and strain. The overall results show that satisfying material formability in better surface finish and geometric dimensional accuracy can be accomplished when the forming conditions are designed appropriately.

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