Blank Shape Design Based on Inverse Finite Element Method Using Ideal Forming Theory and a Modified Kinematics Formulation

Volume 3 ◽  
2004 ◽  
Author(s):  
Mohammad Habibi Parsa ◽  
Payam Pournia
Keyword(s):  
Deformation Gradient ◽  
Design Procedure ◽  
Deformation Gradient Tensor ◽  
Specific Product ◽  
Initial Blank ◽  
Blank Design ◽  
Material Element ◽  
One Step ◽  
Blank Shape ◽  
The Ideal

For stamping of sheet metals and converting them to specific product shapes without failure, the initial blanks should be correctly designed. Otherwise, final products will not be sound. So initial blank design is a critical step in stamping design procedure. In the present paper for calculating the total deformation gradient and its relation to each step’s deformation gradient tensor (F), a modified kinematics formulation will be introduced. This formulation has been used in connection with the ideal forming theory for predicting the initial blank shape of the specified products with defined blank thickness. In the ideal forming theory, each material element is prescribed to deform in a minimum plastic work path and ideal process is obtained when the deformations are most evenly distributed in the final products. The later has been assumed for developing a FEM code to predict the blank shape and size in one step, which has been applied for three different kinds of stampings, cylindrical, square and clover shape cups. The results show the capability of the new algorithm in designing the initial blank shape for stamping products.

Optimal Blank Design for the Drawings of Arbitrary Shapes by the Sensitivity Method

2000 ◽  
Vol 123 (4) ◽  
pp. 468-475 ◽  
Author(s):  
H. B. Shim ◽  
K. C. Son
Keyword(s):  
Shape Sensitivity ◽  
Initial Blank ◽  
Blank Design ◽  
Door Panel ◽  
Explicit Analysis ◽  
Simulation And Experiment ◽  
Deformation Processes ◽  
Final Deformation ◽  
Blank Shape ◽  
Sensitivity Method

The sensitivity method is employed in this work in order to find initial blank shapes which result in desired shapes after deformation. By assuming the final deformation shape be the drawn cup with uniform trimming allowance at the flange, the corresponding initial blank which gives the desired final shape after deformation has been found. With the aid of a well-known dynamic explicit analysis code PAM-STAMP, shape sensitivity has been obtained. To get the shape sensitivity numerically, a couple of deformation processes have been analyzed. Drawings of trapezoidal cup, oil pan, and Audi front door panel, the benchmark test problem of Numisheet ’99, have been chosen as the examples. In every case the optimal blank shape has been obtained after only a few modifications without a predetermined deformation path. With the predicted optimal blank, both computer simulation and experiment are performed. Excellent agreements are obtained between simulation and experiment in every case. Through this investigation, the sensitivity method is found to be very effective in the design of arbitrary shaped drawing processes.

Blank Design by ANN in Bimetallic Deep Drawing

2009 ◽  
Author(s):  
M. R. Morovati Mamaghani ◽  
B. M. Dariani ◽  
M. Haddadzade
Keyword(s):  
Neural Network ◽  
Deep Drawing ◽  
Training Data ◽  
Raw Material ◽  
Drawing Process ◽  
Deep Drawing Process ◽  
Initial Blank ◽  
Blank Design ◽  
Novel Approach ◽  
Blank Shape

The present paper deals with the initial blank design of bimetallic parts obtained by deep drawing process. Normally in deep drawing, the initial blank has a simple shape and after drawing, its perimeter shape will become very complex and has considerable influences on the forming results. If the initial blank shape is designed in such a way that is formed into the desired shape after the drawing process, not only it reduces the time of trimming process, but also decreases the drawing force and the raw material needed substantially. The present paper proposes a novel approach to initial blank optimization in multilayer deep drawing. The Finite Element Method (FEM) is employed for simulating multilayer plate deep drawing process to provide training data for Artificial Neural Network (ANN). The aim of the neural network is to predict the initial blank shape for the desired final shape. The FEM results were verified through experiment.

Optimal Blank Design for the Drawings of Arbitrary Shapes by the Sensitivity Method

2000 ◽  
Author(s):  
H. B. Shim ◽  
K. C. Son
Keyword(s):  
Shape Sensitivity ◽  
Initial Blank ◽  
Blank Design ◽  
Door Panel ◽  
Explicit Analysis ◽  
Simulation And Experiment ◽  
Deformation Processes ◽  
Final Deformation ◽  
Blank Shape ◽  
Sensitivity Method

Abstract The sensitivity method in order to find initial blank shapes which result in desired shapes after deformation has been used in this study.. By assuming the final deformation shape be the drawn cup with uniform trimming allowance at the flange, the corresponding initial blank which gives final shape after deformation has been found. With the aid of a well-known dynamic explicit analysis code PAM-STAMP, shape sensitivity has been obtained. To get the shape sensitivity numerically, a couple of deformation processes have been analyzed. Drawings of trapezoidal cup, oil pan, and Audi front door panel, the benchmark test problem of Numisheet ’99 have been chosen as the examples. At every case the optimal blank shape has been obtained only a few times of modification without predetermined deformation path. With the predicted optimal blank, both computer simulation and experiment are performed. Excellent agreements are recognized between simulation and experiment at every case. Through the investigation the sensitivity method is found to be very effective in the arbitrary shaped drawing process design.

The Refinement Algorithm of Blank Outline Based on One-Step Inverse Analysis

2016 ◽  
Vol 725 ◽  
pp. 517-522
Author(s):  
Jia Kai Zhou ◽  
Yi Dong Bao ◽  
Wan Lin Zhou ◽  
Jing Cui ◽  
Hui Ting Wang
Keyword(s):  
Inverse Analysis ◽  
Computation Time ◽  
Initial Configuration ◽  
Final Configuration ◽  
Characteristic Lines ◽  
Rounded Corner ◽  
Part Surface ◽  
One Step ◽  
Blank Shape ◽  
Refinement Algorithm

Blank dimensions and outlines can be obtained in one-step inverse analysis. Applying more accurate mesh will achieve more precise outlines while usually lead to the increase of computation time. To ensure operation efficiency, this paper proposes a new blank outline refinement algorithm based on one-step inverse analysis. Firstly, the initial configuration is obtained from the final configuration by one-step inverse analysis. Secondly, all outline nodes is projected to the nearest element in the final configuration. Thirdly, according to the position of projected nodes in the element, the coordinate of outline nodes in the initial configuration is achieved through mapping. Finally the number of outline nodes is increased in rounded corners, the coordinate of added nodes are calculated through interpolation. At last all outlines corresponding to characteristic lines of part surface are acquired. Using A-pillar as an example, outlines are calculated by the refinement algorithm and commercial software. It proves that under the same mesh quality, outlines obtained by refinement algorithm become more accurate and smooth, especially in rounded corner. The results can contribute to judge the rationality of blank shape and improve the final part forming property. This algorithm refines the accuracy of outlines and ensures the efficiency of one-step inverse analysis.

scholarly journals An Innovative Optimization Design Procedure for Mechatronic Systems with a Multi-Criteria Formulation

2021 ◽  
Vol 11 (19) ◽  
pp. 8900
Author(s):  
Cuauhtémoc Morales-Cruz ◽  
Marco Ceccarelli ◽  
Edgar Alfredo Portilla-Flores
Keyword(s):  
Optimization Design ◽  
Optimization Problem ◽  
Heuristic Algorithms ◽  
Design Procedure ◽  
Concurrent Design ◽  
Mechatronic Systems ◽  
Design Variables ◽  
One Step ◽  
Task Oriented ◽  
And Task

This paper presents an innovative Mechatronic Concurrent Design procedure to address multidisciplinary issues in Mechatronics systems that can concurrently include traditional and new aspects. This approach considers multiple criteria and design variables such as mechanical aspects, control issues, and task-oriented features to formulate a concurrent design optimization problem that is solved using but not limited to heuristic algorithms. Furthermore, as an innovation, this procedure address all considered aspects in one step instead of multiple sequential stages. Finally, this work discusses an example referring to Mechatronic Design to show the procedure performed and the results show its capability.

scholarly journals Multi-Trigger Thermo-Electro-Mechanical Soft Actuators under Large Deformations

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 489 ◽  
Author(s):  
Ebrahim Yarali ◽  
Reza Noroozi ◽  
Armin Yousefi ◽  
Mahdi Bodaghi ◽  
Mostafa Baghani
Keyword(s):  
Electric Field ◽  
Deformation Gradient ◽  
Free Energy Density ◽  
Radius Of Curvature ◽  
Thermal Stimulus ◽  
The Finite Element Method ◽  
Deformation Gradient Tensor ◽  
Runge Kutta Method ◽  
Stress Components ◽  
Soft Actuators

Dielectric actuators (DEAs), because of their exceptional properties, are well-suited for soft actuators (or robotics) applications. This article studies a multi-stimuli thermo-dielectric-based soft actuator under large bending conditions. In order to determine the stress components and induced moment (or stretches), a nominal Helmholtz free energy density function with two types of hyperelastic models are employed. Non-linear electro-elasticity theory is adopted to derive the governing equations of the actuator. Total deformation gradient tensor is multiplicatively decomposed into electro-mechanical and thermal parts. The problem is solved using the second-order Runge-Kutta method. Then, the numerical results under thermo-mechanical loadings are validated against the finite element method (FEM) outcomes by developing a user-defined subroutine, UHYPER in a commercial FEM software. The effect of electric field and thermal stimulus are investigated on the mean radius of curvature and stresses distribution of the actuator. Results reveal that in the presence of electric field, the required moment to actuate the actuator is smaller. Finally, due to simplicity and accuracy of the present boundary problem, the proposed thermally-electrically actuator is expected to be used in future studies and 4D printing of artificial thermo-dielectric-based beam muscles.

A Design Procedure for Asymptotically Optimal Dynamic Compensators

1990 ◽  
Vol 112 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Kiyotaka Shimizu ◽  
Masakazu Suzuki ◽  
Misao Kato
Keyword(s):  
Optimal Parameter ◽  
Design Method ◽  
Design Procedure ◽  
Pole Placement ◽  
Feedback Gain ◽  
Controlled System ◽  
Parameter Matching ◽  
One Step ◽  
Optimal Dynamic ◽  
Optimal Regulator

This paper is concerned with a design method for optimizing dynamic compensators of Pearson’s type. Optimal parameter matrices are obtained by use of a parameter matching technique and an arbitrary pole placement technique. The controlled system has the optimal LQ modes and the modes with arbitrarily quick damping. The presented compensator works as the optimal regulator with observer and performs about the same control as the optimal regulator. And it is designed not in two steps; observer, regulator, but in one step; optimization of output feedback gain without considering any state estimation.

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