eta/DYNAFORM is an LS-DYNA-based sheet metal forming simulation solution package developed by Engineering Technology Associates, Inc. The specialty CAE software combines the sheet forming analysis power of LS-DYNA Versions 971 with the streamlined pre- and post-processor functions. These analysis codes and interactive functions are uniquely integrated to service the sheet metal forming industry in tooling design and development, which helps designers reduce tooling development time and tryout lead-time.With its superior usability and intelligent tools, eta/DYNAFORM can easily solve all kinds of sheet forming problems. The program also maximizes traditional CAE techniques to reduce prototyping costs and lead 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 code utilizing explicit and implicit capabilities for solving fluid and solid structural problems. The code has been developed for applications such as automobile crashworthiness, occupant safety, underwater explosion, and sheet metal forming.

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 the associated cost for producing high quality stamped parts. eta/DYNAFORM effectively simulates the four major design concerns in the tooling process: Binder Wrap, Draw Die, Springback, and Multiple Stage Tooling. These simulations enable engineers to conduct feasibility studies of a product design early in the design cycle.

eta/DYNAFORM features well-defined tooling surface data to predict the performance of a stamping for areas such as Tearing, Wrinkling, and Thinning, in addition to predicting Skid Mark and Springback effects.

Multi-Platform:

eta/DYNAFORM is available for all UNIX workstation platforms including DEC(Alpha), HP, IBM, SUN, and SGI. It is available on PC for Windows 2000 operating systems and above. For Linux, the Red Hat Enterprise Linux 5 and above is supported.

SPECIAL FEATURES OF ETA/DYNAFORM 5.8 INCLUDE:

A process oriented module- AUTOSETUP

The AutoSetup module consists of Preparation, Sheet Forming, Tube Forming, Rotary Bending, Roller Hemming and Superplastic Forming. The Preparation module is used to prepare the necessary tools for the analysis model; Sheet Forming completes various setups for blank forming analysis, including laser tailor-welded blank, laminated sheet, thermal forming, hydroforming and multi-stage forming; Tube Forming sets up hydroforming for tube; Rotary Bending performs multi-stage bending simulation on tube; Roller Hemming sets up simulation for robot roller hemming process; Superplastic Forming provides a quick setup interface for superplastic forming simulation.

The multi-stage simulation option in the sheet forming module provides a complete set of solutions for engineering problems. It enables the user to complete multiple stage setups fully within the AutoSetup interface and submit for calculation. Users will find the user-friendly interface, concise design style and comprehensive functions in the multi-stage simulation refreshing. This module is process oriented and enables users to easily set up all types of simulation. The sheet forming module combines the merits of user setup power and quick and easy setup. It provides a perfect combination of function and operation while avoiding the traditional disadvantages of difficulty in usage and single quick setting function.

In the sheet forming module, the user can define stamping direction, welded blank simulation, hydroforming simulation, multi-stage simulation and trimming. In addition, thermal forming and cooling simulations are also added to sheet forming. The enhanced material library in AutoSetup module allows the user to add the standard material library for corporations to the program interface for easier selection of common used materials.

Rotary bending is a setup module for tube bending analysis and it is completely in accordance with the practical process. With the user-friendly interface, the user may define a bending axis for arbitrary axis bending, and perform multi-step rotary bending simulation and tubular springback simulation. This module is also equipped with functional modeling for the user to directly create tube and the meshes of various tools for new simulation, which may greatly reduce the setup time and improve modeling efficiency.

The tube forming module is used to set the internal high pressure for forming.  Multiple stage analysis including springback can be performed. The user can adopt the hydraulic mechanism by Pressure and Volume, and the user can also specify a detailed pressure curve. The settings for tube forming are similar to blank hydro forming, which makes it easier to grasp the operating process.

Roller hemming is a setup module for rolling analysis. With the user-friendly interface  the user can define or select a line as its orbit to make the roller move along specified path.

The superplastic forming module is used to analyze capabilities of sheet forming in superplastic temperature range and under specified pressure. It provides a complete scheme for superplastic forming.

The major improvements include:

·           A new Tube Bending (Rotary Bending) application has been added to perform multi-stage tube bending (rotary draw bending) simulations.

·           Added new Roller Hemming GUI in AutoSetup to allow for hemming of separate blank mesh geometries.

·           Added a new Blank Generator GUI to create and prepare initial blank geometry and edit blank mesh.

·           Added a new Tool Preparation GUI in AutoSetup, providing access to a comprehensive set of tools to generate and modify line and surface geometry, as well as generate and modify mesh.

·           Sharing of tools between forming operations in multi-stage simulations has been improved, automatically creating a copy of mesh already assigned as a tool.

·           Activated an option to allow user to set and customize the contact between tools.

·           Expanded MAT_24 (*MAT_PIECEWISE_LINEAR_PLASTICITY) parameters.

·           Added an option to define constraints with (xyz) coordinates in springback stage, which map to appropriate nodal locations.

·           Added an option to define trim seed location with (xyz) coordinates, which maps to the appropriate nodal location.

·           While previewing tooling animation, an arrow will be shown indicating the direction of each applied force, and colored the same as the tool applied to.

·           Supports the import of Unicode curve file format.

·           Supports setting initial reference positioning gap between tools as well as between tools and blank.

·           Definition of tooling geometry is supported in springback simulations.

·           Improved functionality of the Lancing trim option.

·           Added annealing stage, defined by an annealing factor.

Blank Generator

This function enables the user to create blank mesh by adding blank part, importing blank element, meshing surface and blank outline. The major improvements include:

·           Allow user to add blank mesh part to part list and assign as the current blank.

·           Allow user to mesh surface and assign as the current blank.

·           Allow user to import blank mesh and assign as the current blank.

·           Allow user to create blank outline and mesh blank.

·           Provide the related tools for checking and modifying blank mesh.

Updated Drawbead function

This module contains Line Bead and Geometry Bead, which can be easily converted to each other. The user may define the drawbead curve through selection, import and creation and also define the lock force of a drawbead by using four methods. One of the methods is to calculate drawbead force according to section shape, which is very convenient, and the defined section shape is relating to the geometry bead. The line bead can be imported and exported. All operations in drawbead generation, including property definition, modification and project can be easily performed without advanced training. Geometry bead is utilized to create geometry bead mesh according to the defined section shape. It automatically reads in the information of line bead for the creation of geometry mesh model. The user may also import curve directly to define geometry bead. High quality surfaces will also be generated when generating mesh model.

The major improvements include:

·           Added the uplift force calculation in restraining force with theoretical equation.

·           Add force calibrator (DYNA) to calculate its restraining force by simulating method to get the drawbead restraining curve, uplift force curve, plastic strain curve and dimension relation curve.

·           Allow user to import/export calculation results by simulating method.

·           Added the show of force value and force percentage. The user can shift between force value and force percentage in a graphic region.

SCP module

Springback Compensation Process (SCP) is used for die compensation of sprung sheet metal parts. Springback is known to be a crucial issue for the sheet stamping industry. The springback compensation based on finite element technology is utilized to alleviate the severity of springback phenomena. SCP is used to modify the original die face in a direction opposite the springback and by a scaled magnitude generated from the springback simulation to ensure part dimensions fall within the tolerance of the intended part design after springback. The SCP module in eta/DYNAFORM also provides some practical tools for the user to repair the compensated die face and improve the efficiency for die face design.

Improved functionality of DFE module

Compared to the previous version, many functions in the DFE module of eta/DYNAFORM 5.8 are improved to satisfy user needs for friendly and functional operation. New functions including Element Morph, Embossment and Trim Check are added. The user can quickly import the product and complete the entire process of die face design. The major improvements include:

·           Functional Tool Preparation for DFE. The check/modification functions of Line, Surface, Element and Node are combined with the Model Check/Repair functions in an integrated preparation interface for DFE, providing a more convenient and streamlined method for user modification of surface and mesh data, improving process flow.

·           The Tipping Result record has been augmented to allow the user to edit the result values.

·           The editing function for Binder control lines has been improved.  The user can copy the Die part section line from the 2D section window, and assign the Binder section line to match.

·           The “Part on binder” tab has an added Fit Side Step option to extend Side Step mesh to meet the binder mesh.

·           The “Addendum” GUI has been redesigned to simplify the input of profile parameters. Using the improved and optimized addendum algorithm, the user can design addendum with various shapes.

·           The DFE Modification tool set has had a element Morph function added, enabling the user to generate morphed elements within defined regional shapes by adding control curves and/or control points.

·           A new “Embossment” function has been added, allowing the user to create an embossment (a special bead) on existing mesh by specifying radius, depth and wall angle parameters.

·           A Trim Check function has been added to the DFE menu, which enables the user to analyze trim angle, shear angle and scrap size by defining trim line, blank line and cut line.

INC Solver

Huazhong University of Science & Technology (HUST) and Engineering Technology Associates, Inc. (ETA) has jointly developed a specialty Dynamic Non-linear Transient Finite Element program, INC Solver, supporting sheet metal forming applications. A new explicit incremental INC Solver has been implemented in the DFE module to support rapid die face design and analysis of formability concerns.

Enhanced BSE module

In eta/DYNAFORM 5.8, quick unfold, Batch MSTEP and Batch BSE modules are added for the user to perform quick batch operations on multiple parts and output reports. MSTEP is improved to estimate forming capabilities during the part design stage while obtaining the outline. The trim line module is improved to obtain the trim line of complicated parts quickly. The nesting function has also been improved and optimized to satisfy the need forfriendly and functional operation. For nesting of complicated parts, the nesting result yields higher material utilization rate and more practical nesting pattern.

In eta/DYNAFORM 5.8, the BSE module is greatly improved with its concise and easy operating user interface. In addition, improvements and enhancement are added to satisfy users’ needs. The user can import the part model to evaluate outline characteristics and calculate nesting results. The major improvements include:

·           Improved BSE design procedures and integrated portions of the original functions from previous releases. This function enables the user to operate easily and perform part design with their received data.

·           Improved the preparation interface. The functions in the preparation interface are newly integrated and many functions are added in accordance with process flow. 

·           Improved MSTEP to estimate forming capabilities during the part design stage while obtaining the outline.

·           Improved the outline interface so that the use can create and edit an outline by integrating useful preprocessing functions.

·           Improved the nesting function to optimize the nesting result with its friendly user interface and easy operation.

Die System AnalysisDSA

The Die System Analysis module provides a set of solutions for solving practical problems encountered in part production. Finite Element Analysis is utilized to efficiently predict possible problems in a die design and within the die production line to optimize the design of the die structure and the production line. This could greatly reduce try-out time and lower the development cost of new products. The Die System Analysis module includes Die Structural Integrity (DSI), Scrap Shedding Removal (SSR) and Sheet Metal Transferring and Handling (SMTH). In all the analyses of the DSA module, the program provides simple graphic interfaces to guide the user through execution of complicated preparation and simulation processes.

Enhanced Pre-processor functions

·           Improved the “Dynain Contour” function to support plotting of thickness information for solid and T-shell elements.

·           Added an option in the Offset Element function to allow the offset elements to connect with the original mesh.

·           Improved the “Penetration Check” function so that it will take the part thickness property into account.

·           Improved the “Check Coincide Nodes” function to check for duplicated nodes in the same element.

·           Improved the “Overlap Element” function to check for duplicated elements.

·           Added an option in the Edit Default Config (Preprocess-General) window allowing the user to delete free nodes while deleting parts, elements or merging nodes.

·           Added an option to the “Project Line” function which allows the user to project line geometry onto mesh.

·           Increased the character length limit for material names from 8 to 65 characters.

·           Increased the maximum number of points for a line from 500 to 5000.

·           The size of the arrow shown in the display screen when measuring the distance between points will depend on the view/zoom level not the distance.

·           The show element normal function has been improved to will work with shaded model display.

·           Definition of Single Point Constraints in reference to a Local Coordinate System is allowed.

·           Added new “SuperAlloy” materials to the US material library.

·           Added more materials to the Japanese material library.

Support LS-DYNA 971 R5

The input file created by eta/DYNAFORM 5.8 supports LS-DYNA 971R5 format.

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 a draw die simulation of an S-channel and introduces the processes of setup and draw die simulation in detail.

The step-by-step procedure guides users through the complete process and flow of tasks. A new user can usually complete the training program and be ready to begin a production project in less than two hours.

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

Case 1.  NUMISHEET’2002 Fender Draw Simulation

Case 2.  Double Action of Solid Element Simulation

Case 3.  Springback and Springback Compensation Simulation

Case 4.  Tube Bending and Hydroforming Simulation

Case 5.  Multi-Step Rotary Bending

These workshop examples enable 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 springback simulation.

The eta/DYNAFORM User Manual describes functions of the software interface.

For further details about LS-DYNA, please refer to the LS-DYNA Keyword User’s Manual published by the Livermore Software Technology Corporation (LSTC) of Livermore, California.