June 15-18, 2010.  
class runs 9:00 a.m. and until 5:00 p.m

EARLY REGISTRATION IS RECOMMENDED
ENROLLMENT IS LIMITED TO 20 STUDENTS

Completed registration cards may be sent by mail
or FAX with check, or purchase order.   
Registration form pdf 88KB 
Registration prior to May 15  $800
Registration after May 15  $900

COURSE OBJECTIVES

This course is intended to be an introduction to the latest techniques for modeling sheet metal forming operations. It is intended that engineers, scientists, and researchers should gain a critical understanding of the obstacles to accurate sheet forming simulations, and the methods within LS-DYNA for overcoming these obstacles. The course shall be presented in an applied manner, with an emphasis on techniques which will allow industrial forming operations to be simulated.

WHO SHOULD ATTEND

This seminar is ideal for engineers and scientists who wish to develop or upgrade their understanding and capability of modeling sheet forming operations.

COURSE CONTENTS

INTRODUCTION:

• Introduction to sheet forming

• Benefits of sheet forming simulations

• Introduction to finite element analysis

• Numerical methods for finite element analysis

• Implicit versus explicit time integration schemes

BASICS OF SHEET FORMING SIMULATIONS:

• One-Step methods

• Definition of tooling geometry

• Selection of element type and size

  • shell elements versus continuum elements

  • shell formulations for sheet forming and spring back analysis

• Modelling the interaction between blank and tools

  • penalty functions versus Lagrange multipliers

  • automatic contact definition

  • one-way versus two-way treatment of contact

  • friction modelling

  • checks for over-penetration

  • thickness offsets and negative thickness offsets

• Material definition for the deforming blank

  • relationships between stress and strain in large deformation plasticity

  • defining work hardening behavior

  • yield surface definition

    • isotropic plasticity

    • material anisotropy

• Boundary Conditions

  • applying forces and displacements to tools

  • birth and death time for boundary conditions

  • modeling the action of nitrodyne cylinders in the press

  • preventing opening and closing of the binders during the analysis

Running LS-DYNA:

• Mechanics of running LS-DYNA

  • output file names, running restarts, dumpfiles

  • control switches for monitoring progress

  • running dyna interactively or in batch Time scaling for reduced cpu time

  • dangers of dynamic effects: how to identify, quantify, and minimize

Post-processing in LS-PREPOST:

• viewing deformed geometry

• plotting contours and fringes such as stress and strain on deformed geometry

• history plots

• plotting ASCII file output on screen as x-y graphs

• saving screen images

LS-DYNA SHEET FORMING ENHANCEMENTS:

• Mass scaling

  • reducing cpu time for modelling quasi-static events

  • controlling minimum time step in distorted elements

• Draw bead models

• Rigid body stoppers

• Adaptive remeshing

  • minimization of discretization error

  • efficient generation of meshes for the blank

  • effect of adaptive remeshing parameters on forces, cpu time

• Forming limit diagrams and Circle Grid Analysis

• Multi-stage forming processes

Post-processing Options

• Forming Limit Diagrams

• Circle Grid Analysis

• Failure ratio

• Trimming

  • Spacial Definition of trim curves

  • Deletion of elements in trim regions

  • Movement of nodes to the trim curve

  • Trimming after LS-DYNA run

Spring Back Analysis

• Theory of spring back

• Choice of elements for spring back analysis

• Spring back calculated by LS-DYNA

• Advantages of implicit codes for spring back

• Introduction to LS-DYNA implicit

• Running LS-DYNA for spring back analysis

• Springback Compensation

Send questions and comments to galb@mfac.com