A Study on Inverse Problem of Materials Forming Process using Optimization Technique and Distributed Computing

2004 ◽  
Vol 28 (5) ◽  
pp. 632-639
Keyword(s):  
Inverse Problem ◽  
Distributed Computing ◽  
Optimization Technique ◽  
Forming Process

scholarly journals Application of the topological sensitivity method to the reconstruction of plasma equilibrium domain in a tokamak

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Mohamed Abdelwahed ◽  
Nejmeddine Chorfi ◽  
Maatoug Hassine ◽  
Imen Kallel
Keyword(s):  
Inverse Problem ◽  
Asymptotic Expansion ◽  
Numerical Algorithm ◽  
Shape Function ◽  
Optimization Technique ◽  
Plasma Equilibrium ◽  
Topological Sensitivity ◽  
Sensitivity Method

AbstractThe topological sensitivity method is an optimization technique used in different inverse problem solutions. In this work, we adapt this method to the identification of plasma domain in a Tokamak. An asymptotic expansion of a considered shape function is established and used to solve this inverse problem. Finally, a numerical algorithm is developed and tested in different configurations.

A Comparison of Two Solution Techniques for the Inverse Problem of Simultaneously Estimating the Spatial Variations of Diffusion Coefficients and Source Terms

2003 ◽  
Author(s):  
Marcelo J. Colac¸o ◽  
Helcio R. B. Orlande ◽  
George S. Dulikravich ◽  
Fabio A. Rodrigues
Keyword(s):  
Inverse Problem ◽  
Gradient Method ◽  
Optimization Technique ◽  
Adjoint Problem ◽  
Diffusion Problem ◽  
Hybrid Optimization ◽  
Simultaneous Estimation ◽  
Random Errors ◽  
Flow Detection ◽  
Solution Techniques

This work deals with the simultaneous estimation of the spatially varying diffusion coefficient and of the source term distribution in a one-dimensional nonlinear diffusion problem. This work can be physically associated with the detection of material non-homogeneities such as inclusions, obstacles or cracks, heat conduction, groundwater flow detection, and tomography. Two solution techniques are applied in this paper to the inverse problem under consideration, namely: the conjugate gradient method with adjoint problem and a hybrid optimization algorithm. The hybrid optimization technique incorporates several of the most popular optimization modules; the Davidon-Fletcher-Powell (DFP) gradient method, a genetic algorithm (GA), the Nelder-Mead (NM) simplex method, quasi-Newton algorithm of Pshenichny-Danilin (LM), differential evolution (DE), and sequential quadratic programming (SQP). The accuracy of the two solution approaches was examined by using simulated transient measurements containing random errors in the inverse analysis.

scholarly journals Optimization of shot peen forming patterns to achieve complex target shapes the inverse problem

2021 ◽  
Author(s):  
Hong Yan Miao ◽  
Martin levesque ◽  
Frederick Gosselin
Keyword(s):  
Inverse Problem ◽  
Optimization Procedure ◽  
Spherical Shape ◽  
Forming Process ◽  
Peen Forming ◽  
Out Of Plane ◽  
Order Of Magnitude ◽  
Complex Target ◽  
Wing Skin ◽  
Relative Differences

The inverse problem of determining how to shot peen a plate such that it deforms into a desired target shape is a challenge in the peen forming industry. While peening thick plates uniformly on one side results in a spherical shape, with the same curvature in all directions, complex peening patterns are required to form other shapes, such as cylinders and saddles found on fuselages and wing skin panels. In this study, we present an optimization procedure to automatically compute shot peening patterns. This procedure relies on an idealized model of the peen forming process, where the effect of the treatment is modeled by in-plane expansion of the peened areas, and on an off-the-shelf optimization algorithm. For validation purposes, we peen formed three 305 X 305 X 4.9 mm and two 762 X 762 X 4.9mm 2024--T3 aluminium alloy plates into cylindrical and saddle shapes using the same peening treatment. The obtained shapes qualitatively match simulations. For 305 X 305 X 4.9mm plates, the relative differences had the same distribution and were of the same order of magnitude as initial out-of-plane deviations measured on the as-received plates.

scholarly journals Optimize the Rolling Process Parameters for Material AA1100 using Metal Forming Simulation

2018 ◽  
Vol 144 ◽  
pp. 03005
Author(s):  
T. S. Hemanth ◽  
Y. Arunkumar ◽  
M. S. Srinath.
Keyword(s):  
Effective Stress ◽  
Metal Forming ◽  
Optimization Technique ◽  
Rolling Process ◽  
Simulation Software ◽  
Percentage Reduction ◽  
Forming Process ◽  
Taguchi Optimization ◽  
Manufacturing Simulation ◽  
Forming Simulation

Metal forming plays a very important role in the manufacturing. Simulation of manufacturing process aids in the improvement of quality, reduce energy and resource consumption and helps in visualization of the process. The design of experiment helps in optimization of the parameters in any processes. In this paper, Taguchi optimization technique is used to predict the best results for the given inputs such as roller diameter, friction value, velocity of the rollers and percentage reduction to the forming process and get the optimized values for spread, hardness, effective stress, power required, strain rate and torque using the manufacturing simulation software. It is found that the important parameter is percentage reduction affecting the effective stress. Optimal parameters with desirability value of 0.87 have been obtained.

The Influence of the Roller Forming Path on the Neck-Spinning Process of Tube at Elevated Temperature

2011 ◽  
Author(s):  
Chi-Chen Huang ◽  
Jung-Chung Hung ◽  
Cheng-Chan Lo ◽  
Chia-Rung Lin ◽  
Chinghua Hung
Keyword(s):  
Finite Element ◽  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Thickness Distribution ◽  
Optimization Technique ◽  
Element Model ◽  
Strain Rates ◽  
Forming Process ◽  
Tube Spinning ◽  
Spinning Process

The tube spinning process is a metal forming process used in the manufacture of axisymmetric products, and has been widely used in various applications. In this paper, the neck-spinning process was applied to form the neck part of the tube end at an elevated temperature. The spun tube was used as a high pressure CO2 vessel, which is a component of motorcycle airbag jackets. An uneven surface will occur on the tube surface if the thickness distribution of the tube is not uniform after the neck-spinning process. This is because different thicknesses result from different contractions during the cooling stage. For this reason, the aim of this research was to numerically investigate the roller forming path to improve the thickness distribution of the tube during the neck-spinning process. The finite element method was used to simulate the neck-spinning process of the tube at an elevated temperature. For the construction of the material model, special uni-axial tensile tests were conducted at elevated temperatures and various strain rates, because the material is sensitive to strain rates at high temperatures. This paper compares the experimental and simulation results of the thickness distribution and the outer contour of the spun tube. The validated finite element model was used to investigate the influence of the roller forming path on the thickness distribution of the tube. The thickness distribution of the tube formed by a curved path was found to be more uniform than for the tube formed by a straight path. Finally, the optimization technique was used to find the optimal forming path, and the optimal result was verified experimentally.

An Efficient Method for Crack Identification in Simply Supported Euler–Bernoulli Beams

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
L. Rubio
Keyword(s):  
Inverse Problem ◽  
Mass Density ◽  
Optimization Technique ◽  
Least Square ◽  
Closed Form Expression ◽  
Crack Identification ◽  
Cracked Beam ◽  
Identification Procedure ◽  
Simply Supported ◽  
Euler Bernoulli Beam

An effective crack identification procedure has been developed based on the dynamic behavior of a Euler–Bernoulli cracked beam. It is very well known that the presence of a crack in a structure produces a change in its frequency response that can be used to determine the crack properties (position and size) solving what is called an inverse problem. In this work, such an inverse problem has been solved by the use of the classical optimization technique of minimizing the least square criterion applied to the closed-form expression for the frequencies obtained through the perturbation method. The advantage of this method with respect to the ones derived previously is that the knowledge of the material and its properties (Young’s modulus and mass density) is not necessary, not even the behavior of the uncracked element. The methodology has been successfully applied to a simply supported Euler–Bernoulli beam.

scholarly journals Determination of optimal shot peen forming patterns using the theory of non-Euclidean plates

2021 ◽  
Author(s):  
Vladislav Sushitskii ◽  
Wim M van Rees ◽  
Martin levesque ◽  
Frederick Gosselin
Keyword(s):  
Inverse Problem ◽  
Theoretical Approach ◽  
Theoretical Framework ◽  
Forward Problem ◽  
Test Cases ◽  
Practical Realization ◽  
Forming Process ◽  
Target Shape ◽  
Peen Forming

We show how a theoretical framework developed for modelling nonuniform growth can model the shot peen forming process. Shot peen forming consists in bombarding a metal panel with multiple millimeter-sized shot, that induce local bending of the panel. When applied to different areas of the panel, peen forming generates compound curvature profiles starting from a flat state. We present a theoretical approach and its practical realization for simulating peen forming numerically. To achieve this, we represent the panel undergoing peen forming as a bilayer plate, and we apply a geometry-based theory of non-Euclidean plates to describe its reconfiguration. Our programming code based on this approach solves two types of problems: it simulates the effect of a predefined treatment (the forward problem) and it finds the optimal treatment to achieve a predefined target shape (the inverse problem). Both problems admit using multiple peening regimes simultaneously. The algorithm was tested numerically on 200 randomly generated test cases.

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