INTRODUCTION

The eta/DYNAFORM Version 5.1 software is an LS-DYNA-based sheet metal forming simulation solution package developed by Engineering Technology Associates, Inc. This specialty CAE software combines the analysis power of LS-DYNA Version 960 and 970, with the streamlined pre- and post-processor functions of eta/DYNAFORM. These analysis codes and interactive functions are uniquely integrated to service the sheet metal forming industry in tooling design and development. The program also maximizes traditional CAE techniques to reduce the prototyping costs and cycle time for product development.

eta/DYNAFORM's analysis engine is LS-DYNA, which is developed and currently supported by the Livermore Software Technology Corporation (LSTC) of Livermore, California. It is a general purpose, non-linear, dynamic, finite element analysis codes utilizing explicit and implicit solver approaches for fluid and solid structural problems. This code has been developed for applications such as automobile crashworthiness, occupant safety, underwater explosion, sheet metal forming, etc.

The bottleneck of the metal forming development cycle is the hard tooling design lead-time. The eta/DYNAFORM CAE approach simulates this tooling process and thereby reduces the tooling tryout time and cost required to produce high quality panels and stamped parts. Specifically, eta/DYNAFORM effectively simulates the four major design concerns in the tooling process: Binder Wrap, Draw Die, Spring Back, and Multiple Stage Tooling. These simulations enable engineers to conduct feasibility studies of a product design early in the design cycle.

Users can also take advantage of well-defined tooling surface data to predict the performance of a panel stamp in areas such as cracking, wrinkling, and thinning, in addition to predicting skid mark and spring back effects.

Availability:

eta/DYNAFORM is available for all UNIX workstation platforms including DEC(Alpha), HP, IBM, SUN, and SGI. It is available on PC for Windows NT operating systems and 1998 and above. For LINUX, the RedHat version 7.2 and above is supported.

Special features for eta/DYNAFORM Version 5.0 include:

Quick-Setup (QS)

The newly developed QS supports the following simulations:

Gravity Loading

Draw Die - Crash Forming, Single Action, Double Action and 4-Piece Tooling Set-ups

Springback

The QuickSetup interface is designed to help the user set up a simulation quickly and easily. All the default parameters related to the Quick-Setup are located in the advanced menu located in the QuickSetup interface. The user can change the default settings according to his preference.

The Quick-Setup utilizes a numerical contact offset instead of a geometry offset to alleviate small and overlapping elements in offset tooling geometry.

Embedded Material Library

The most commonly used material models for steel, high strength steel and aluminum are organized in a library for quick selection. The new library is located under Tools/ Material/Material Library. The library is also accessible in the QS Menus under "Blank Material".

STL Reader Implementation

DYNAFORM reads stereo lithography (STL format or .stl) geometry information, commonly used by scanning operations, and converts it into triangular elements.

Default Parameters and Configuration Control

Provides a two-level authorization system to enable the supervisor or super-user to implement default values and parameters in addition to the user's ability to customize processes and applications.

The DYNAFORM Default file located in both the program installation directory and the user's home directory allows a user to modify default parameters, including file extensions, contact parameters, adaptive mesh parameters, output control parameters etc.

A detailed explanation regarding the default parameters is provided at the beginning of the DYNAFORM Default file.

Improved Model Check Interface

Reorganize Model Check Icons and Parameter Settings for improved model analysis.

Documentation

A Training Manual is available to assist first time users with the general operating procedures of the program. The manual includes a relatively simple demonstration of the draw die simulation of an S-channel using LS-DYNA. This example describes the process of setting up and running a stamping simulation.

A step-by-step procedure is provided to guide users through the complete process and flow of the tasks. In most cases, new users can complete the training program in less than two hours and be ready to begin a production project.

The eta/DYNAFORM Applications Manual discusses the basics of the sheet metal forming process and provides users with some fundamental knowledge of tooling design and related topics. The following are typical examples of simulations that are included to demonstrate eta/DYNAFORM's capabilities, features, and functions:

Case 1. Binder Wrap Simulation

Case 2. NUMISHEET'93 Fender Simulation

Case 3. Cup Draw Simulation with Adaptive Mesh

Case 4. S-Rail NUMISHEET'96 Simulation with Spring Back

Case 5. Hydro Forming Simulation

These workshop examples help users to fully understand general pre- and post-processing operations in addition to the applications of binder wrap simulation, draw bead force calculation, draw die simulation, Forming Limit Diagram (FLD), thickness, thinning, wrinkling, and spring back simulation.

The User's Manual contains function descriptions specific to the DYNAFORM interface.

For further details on LS-DYNA, users are kindly asked to refer to the respective manuals for these codes published by the Livermore Software Technology Corporation.