Implicit Analysis using LS-DYNA

In recent years, the simulation possibilities in LS-DYNA using implicit time integration have been enhanced extensively. The main areas of application for implicit analyses include linear and non-linear static computations, natural frequency analyses, springback, lengthy transient simulations, systems with preload, etc. The aim of the seminar is to give participants an overview of the possibilities and limits of implicit simulations using LS-DYNA. In particular, attention will be drawn on the required input cards for such simulations.

The seminar is recommended for engineers intending to use LS-DYNA to carry out implicit simulations. In addition, experienced “explicit users” learn about what to bear in mind when converting explicit into implicit input decks. Examples will be given during the seminar to illustrate the functionality of the implicit options.

Contents

• Differences between explicit and implicit: theory, application, examples
• Input syntax for implicit control cards
• Linear static analysis: options, linear elements, boundary constraints, direct/iterative solvers, accuracy
• Dynamic analysis: Newmark method, input parameters, lumped/consistent mass matrix
• Nonlinear analysis: solution methods (Newton, BFGS, arclength), convergence, tolerances, output, automatic step size strategy
• Eigenvalue analysis: options, modeling aspects, intermittent output
• Modal analysis, linear buckling
• Frequency response function
• Switching: implicit/explicit, explicit/implicit
• Element types for implicit: linear and nonlinear elements
• Material models for implicit analyses
• Contact types for implicit: options, Mortar contact
• Troubleshooting convergence problems
• Summary with checklist of most important settings for implicit calculations

Basic knowledge of LS-DYNA or prior attendance at the seminar Introduction to LS-DYNA is recommended.