Design Sensitivity Analysis of Nonlinear Shell Structure With Frictionless Contact

2003 ◽  
Author(s):  
Kyung K. Choi ◽  
Kiyoung Yi ◽  
Nam H. Kim ◽  
Mark E. Botkin
Keyword(s):  
Sensitivity Analysis ◽  
Finite Deformation ◽  
Shell Structure ◽  
Design Sensitivity ◽  
Design Sensitivity Analysis ◽  
Integration Scheme ◽  
Configuration Design ◽  
Sensitivity Equation ◽  
Material Derivative ◽  
Frictionless Contact

A continuum-based shape and configuration design sensitivity analysis method for a finite deformation elastoplastic shell structure with frictionless contact has been developed. Shell elastoplasticity is treated based on the projection method that performs the return mapping on the subspace defined by the zero-normal stress condition. An incrementally objective integration scheme is used in the context of finite deformation shell analysis, wherein stress objectivity is preserved for finite rotation increments. The penalty regularization method is used to approximate the contact variational inequality. The material derivative concept is used to develop continuum based design sensitivity. The design sensitivity equation is solved without iteration at each converged load step. Numerical implementation of the proposed shape and configuration design sensitivity analysis is carried out using the meshfree method. The accuracy and efficiency of the proposed method is illustrated using numerical examples.

Design Sensitivity Analysis for the Meshfree Shell Structure

2001 ◽  
Author(s):  
Kyung K. Choi ◽  
Nam H. Kim ◽  
Mark E. Botkin
Keyword(s):  
Sensitivity Analysis ◽  
Shell Structure ◽  
Design Sensitivity ◽  
Design Sensitivity Analysis ◽  
Analysis Method ◽  
Sensitivity Equation ◽  
Material Derivative ◽  
Design Variables ◽  
Sensitivity Analysis Method ◽  
Shell Formulation

Abstract A unified design sensitivity analysis method for a meshfree shell structure with respect to sizing, shape, and configuration design variables is presented in this paper. A shear deformable shell formulation is characterized by a CAD connection, thickness degeneration, meshfree discretization, and nodal integration. The design variable is selected from the CAD parameters, and a consistent design velocity field is then computed by perturbing the surface geometric matrix. The material derivative concept is used to obtain a design sensitivity equation in the parametric domain. Numerical examples show the accuracy and efficiency of the proposed design sensitivity analysis method compared to the analytical solution and the finite difference solution.

Continuum-Based Design Sensitivity Analysis and Optimization of Springback in Stamping Process

2005 ◽  
Author(s):  
Kyung K. Choi ◽  
Kiyoung Yi ◽  
Nam H. Kim ◽  
Mark E. Botkin
Keyword(s):  
Sensitivity Analysis ◽  
Process Development ◽  
Design Sensitivity ◽  
Design Sensitivity Analysis ◽  
Forming Process ◽  
Sensitivity Equation ◽  
Material Derivative ◽  
Stamping Process ◽  
Sensitivity Analysis Method ◽  
Blank Holding Force

The springback is a significant manufacturing defect in the stamping process. A serious impediment to the use of lighter-weight, higher-strength materials in manufacturing is the relative lack of understanding about how these materials respond to the complex forming process. The springback problem can be reduced by using appropriate designs of die, punch, and blank holder shape together with friction and blank holding force. That is, an optimum stamping process can be determined using a gradient-based optimization to minimize the springback. However, for an effective optimization of the stamping process, development of an efficient analytical design sensitivity analysis method is crucial. In this paper, a continuum-based shape and configuration design sensitivity analysis (DSA) method for the stamping process has been developed. The material derivative concept is used to develop the continuum-based design sensitivity. The design sensitivity equation is solved without iteration at each converged load step in the finite deformation elastoplastic nonlinear analysis with frictional contact, which makes the design sensitivity calculation very efficient. The accuracy and efficiency of the proposed method is illustrated by minimizing springback in an S-rail part, which is often used as an industrial benchmark to verify the numerical procedures employed for stamping processes.

Sign in / Sign up

Export Citation Format

Share Document