A Dexterous Part-Holding Model for Handling Compliant Sheet Metal Parts

2001 ◽  
Vol 124 (1) ◽  
pp. 109-118 ◽  
Author(s):  
H. F. Li ◽  
D. Ceglarek ◽  
Jianjun Shi
Keyword(s):  
Production Rate ◽  
Sheet Metal ◽  
Material Handling ◽  
Experimental Studies ◽  
Model Parameters ◽  
Element Analysis ◽  
End Effector ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
End Effectors

Material handling of compliant sheet metal parts significantly impacts both part dimensional quality and production rate in the stamping industry. This paper advances previously developed material handling end effector layout optimization methodology for rigid point end effectors [1] by developing a dexterous part-holding end effector model. This model overcomes the shortcomings of the rigid point part-holding end effector model by predicting part deformation more accurately for various modes of deformation and for a set of part-holding end effector locations. This is especially important for handling systems which utilize vacuum cup end effectors widely used for handling of large sheet metal parts. The dexterous end effector model design method and an algorithm for estimation of model parameters are developed. The algorithm combines data from design of computer simulations and from the set of experiments by integrating finite element analysis and a statistical data processing technique. Experimental studies are conducted to verify the developed model and the model parameter estimation algorithm. The developed methodology provides an analytical tool for product and process designers to accurately predict part deformation during handling, which further leads to minimization of part deformation, improvement of part dimensional quality and increase of production rate.

Optimal Trajectory Planning For Material Handling of Compliant Sheet Metal Parts

2002 ◽  
Vol 124 (2) ◽  
pp. 213-222 ◽  
Author(s):  
Huifang Li ◽  
Dariusz Ceglarek
Keyword(s):  
Production Rate ◽  
Sheet Metal ◽  
Trajectory Planning ◽  
Optimal Trajectory ◽  
Material Handling ◽  
Horizontal Distance ◽  
Mathematical Tool ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Optimal Trajectory Planning

One of the most critical issues in the material handling of compliant objects is excessive part deformation. The deformation of compliant sheet metal parts during the handling process can significantly impact both part dimensional quality and production rate. Increasing production rate while maintaining part quality requires an optimal design of the part transfer trajectory. This paper describes a new methodology of time-optimal trajectory planning for compliant parts by discretizing the part transfer path into N segments that have equal horizontal distance and by approximating the trajectory as having piecewise constant acceleration that can only change its value at the end of each segment. The contribution of the methodology is that part deformation determined by transfer velocity and acceleration is considered as a nonlinear constraint, which is obtained from FEA simulation and model fitting. Part permanent deformation, trajectory smoothness, and static obstacle avoidance are also considered. The methodology is validated by simulations at different motion conditions and obstacle configurations. This paper addresses the lack of current design guidelines for material handing development and simultaneously provides a mathematical tool to significantly enhance the production efficiency in manufacturing of compliant sheet metal parts.

Optimisation of Springback Predicted by Experimental and Numerical Approach by Using Response Surface Methodology

2005 ◽  
Vol 6-8 ◽  
pp. 753-762
Author(s):  
R. Bahloul ◽  
Phillippe dal Santo ◽  
Ali Mkaddem ◽  
A. Potiron
Keyword(s):  
Response Surface ◽  
Sheet Metal ◽  
Design Method ◽  
Fem Simulation ◽  
Numerical Approach ◽  
Tool Geometry ◽  
Nose Radius ◽  
Element Analysis ◽  
Metal Parts ◽  
Sheet Metal Parts

Bending has significant importance in the sheet metal product industry. Moreover, the springback of sheet metal should be taken into consideration in order to produce bent sheet metal parts within acceptable tolerance limits and to solve geometrical variation for the control of manufacturing process. Nowadays, the importance of this problem increases because of the use of sheet-metal parts with high mechanical characteristics (High Strength Low Alloy steel). This work describes robust methods of predicting springback of parts in 3D modelling subjected to bending and unbending deformations. Also the effects of tool geometry in the final shape after springback are discussed. The first part of this paper presents the laboratory experiments in wiping die bending, in which the influence of process variables, such as die shoulder radius, punch-die clearance, punch nose radius and materials properties were discussed. The second part summarises the finite element analysis by using ABAQUS software and compares these results with some experimental data. It appeared that the final results of the FEM simulation are in good agreement with the experimental ones. An optimisation methodology based on the use of experimental design method and response surface technique is proposed in the third part of this paper. That makes it possible to obtain the optimum values of clearance between the punch and the die and the optimum die radius which can reduce the springback without cracking and damage of product.

Modeling and Optimization of End Effector Layout for Handling Compliant Sheet Metal Parts

2000 ◽  
Vol 123 (3) ◽  
pp. 473-480 ◽  
Author(s):  
D. Ceglarek ◽  
H. F. Li ◽  
Y. Tang
Keyword(s):  
Sheet Metal ◽  
Material Handling ◽  
Design Stage ◽  
End Effector ◽  
Industrial Practice ◽  
Modeling And Optimization ◽  
Sheet Metal Stamping ◽  
Sheet Metal Parts ◽  
Metal Stamping ◽  
Compliant Parts

Material handling of compliant parts is one of the most critical and underresearched problems in the sheet metal stamping industry. The fundamental shortcoming of currently studied material handling systems for sheet metal stamping is the lack of analysis of its impact on part dimensional quality and production throughput. This paper addresses this problem by development of a generic methodology for modeling and optimization of part holding end-effector layout in order to minimize part dimensional deformation during handling operations. The methodology extends the design of “N-2-1” fixturing layout by adding part movability conditions. It considers part CAD model, handling direction and motion kinematic parameters to determine the best end effector layout. This methodology is realized by integrating FEM part and loading modeling with the optimization algorithm. It can be implemented into the design stage of a stamping line so that the trial and error process, which is current industrial practice, can be greatly shortened and the production throughput increased. Experimental results verify the proposed part holding end-effector layout methodology.

Deformable Sheet Metal Fixturing: Principles, Algorithms, and Simulations

1996 ◽  
Vol 118 (3) ◽  
pp. 318-324 ◽  
Author(s):  
W. Cai ◽  
S. J. Hu ◽  
J. X. Yuan
Keyword(s):  
Sheet Metal ◽  
Rigid Bodies ◽  
Fixture Design ◽  
Total Deformation ◽  
Element Analysis ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Manufacturing Operations ◽  
Nonlinear Programming Methods ◽  
Simulation Package

Fixture design is an important consideration in all manufacturing operations. Central to this design is selecting and positioning the locating points. While substantial literature exists in this area, most of it is for prismatic or solid workpieces. This paper deals with sheet metal fixture design. An “N-2-1” locating principle has been proposed and verified to be valid for deformable sheet metal parts as compared to the widely accepted “3-2-1” principle for rigid bodies. Based on the “N-2-1” principle algorithms for optimal fixture design are presented using finite element analysis and nonlinear programming methods to find the best “N” locating points such that total deformation of the deformable sheet metal is minimized. A simulation package called OFixDesign is introduced and numerical examples are presented to validate the “N-2-1” principle and optimal sheet metal fixture design approach.

Press Forging Forming of Stepped Holes in Thick Sheet Metal

2013 ◽  
Vol 706-708 ◽  
pp. 234-237
Author(s):  
Xu Jun Cao ◽  
Ke Sheng Wang ◽  
Yu Han ◽  
Chong Chao Lin
Keyword(s):  
Sheet Metal ◽  
Effective Strain ◽  
Extrusion Process ◽  
Thick Sheet ◽  
Element Analysis ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Thick Sheet Metal ◽  
Deform 3D ◽  
Good Agreement

Press forging forming of thick sheet metal is a combined extrusion process, which is put forward in the presently study. A new technological scheme for a two-step press forging of stepped holes in a thick metal sheet was proposed. Finite element analysis on the two-step process is carried out by using DEFORM-3D. Distributions of effective strain and effective stress were obtained. The study showed that the process not only can form the stepped holes, but also can increase the surface quality and strength of stepped holes in sheet metal parts, According to the numerical simulations process parameter, an experimental die was designed, the simulation results were in good agreement with the experimental data.

Modeling and Optimization of Fixture for Handling Compliant Sheet Metal Parts

1999 ◽  
Author(s):  
D. Ceglarek ◽  
H. F. Li ◽  
Y. Tang
Keyword(s):  
Sheet Metal ◽  
Material Handling ◽  
Design Stage ◽  
End Effector ◽  
Industrial Practice ◽  
Modeling And Optimization ◽  
Sheet Metal Stamping ◽  
Sheet Metal Parts ◽  
Metal Stamping ◽  
Compliant Parts

Abstract Material handling of compliant parts is one of the most critical and underresearched problems in the sheet metal stamping industry. The fundamental shortcoming of currently studied material handling systems for sheet metal stamping is the lack of analysis of its impact on part dimensional quality and production throughput. This paper addresses this problem by development of a generic methodology for modeling and optimization of part holding end-effector fixture layout in order to minimize part dimensional deformation during handling operations. The methodology extends the design of “N-2-1” fixturing layout by adding part movability conditions. It considers part CAD model, handling direction and motion kinematic parameters to determine the best end effector layout. This methodology is realized by integrating FEM part and loading modeling with the optimization algorithm. It can be implemented into the design stage of a stamping line so that the trial and error process, which is current industrial practice, can be greatly shortened and the production throughput increased. Experimental results verify the proposed part holding end-effector layout methodology.

FE Simulation of Sheet Metal Forming – State of the Art in Automotive Industry

2005 ◽  
Vol 6-8 ◽  
pp. 13-18 ◽  
Author(s):  
H.J. Haepp ◽  
M. Rohleder
Keyword(s):  
Sheet Metal ◽  
Automotive Industry ◽  
Development Process ◽  
High Strength Steels ◽  
Feasibility Studies ◽  
High Strength ◽  
Element Analysis ◽  
Early Design ◽  
Metal Parts ◽  
Sheet Metal Parts

Nowadays feasibility studies using finite element analysis are performed in very early design phases of sheet metal parts forming. Further, simulation technology is used to optimize the first forming stage. Because of the ever intensifying international competition and the increased use of high-strength steels and aluminum alloys, the absorption of springback deviations is a great challenge, especially in the automotive industry. The application of numerical computation to predict springback deviations and to create compensated die designs in early design phases of sheet metal parts forming becomes essential. At DaimlerChrysler the numerically based compensation of springback deviations during the die development process of complex car parts is achieved. However, developments to optimize and compensate dies automatically or to predict form deviations on assemblies are still necessary.

Location optimization of interchangeable parts in sheet metal assembly

2016 ◽  
Vol 232 (10) ◽  
pp. 1848-1857
Author(s):  
Honglun Huan
Keyword(s):  
Sheet Metal ◽  
Complete Bipartite Graph ◽  
Perfect Match ◽  
Prediction Method ◽  
Stiffened Panel ◽  
Flexible Beam ◽  
Element Analysis ◽  
Location Optimization ◽  
Metal Parts ◽  
Sheet Metal Parts

Stiffened panel is a kind of structure that is widely used in aviation manufacturing. Some sheet metal parts in the structure have three characteristics: place-interchangeable, large quantity and stochastic variation caused by spring back or distortion in manufacturing process, which prominently impacts the assembly variation. In order to minimize the influence and improve the assembly quality of stiffened panel, a model based on flexible beam is established and a simplified and approximate assembly variation prediction method is obtained. Furthermore, for the interchangeable sheet metal parts, the assembly location optimization method based on the algorithm of perfect match of weighted complete bipartite graph is proposed. At last, case study on a fuselage panel assembly is implemented. The finite element analysis results show the reliability of the simplified variation prediction method and the necessity of assembly location optimization.

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