There is a phrase among finite element analyst user community. Those who have been in the industry since a while must have heard of it at some point in their career.

     GARBAGE IN….GARBAGE OUT

It means that if the data being fed into the input deck is not correct or appropriate, the solver is very likely to give incorrect results, and that’s if it does not fail with errors. Many of us believe that getting some sort of result is better than getting fatal errors, which is not correct. Fatal errors give clear diagnostic messages to the user that allow him to correct the input deck. However, getting erroneous results sometimes makes a user feel that the simulation has been successful even though the results may be far from reality. Such situations are hard to predict and correct, as the underlying cause is not clearly visible.

One such situation arises when the user inadvertently chooses an element type that is not capable of capturing the actual physical behavior of the part or assembly with which the element is associated. The incompatibility may lie with respect to element material, element topology, element dimension, or the type of output associated with the element. The objective of this post is to highlight the capabilities and limitations of some lesser known element types available in the Abaqus element library to promote their proper usage.

Planar elements

These elements are further classified as either plane stress (CPS) or plane strain elements (CPE). The plane stress elements are used to model thin structures such as composite plate. These elements must be defined and can deform only in X-Y plane. For these types of elements:

szz = t xz = t yz = 0

The plane strain elements are used to model thick structures such as rubber gaskets. These types of elements must be defined and can deform only in X-Y plane. For these types of elements:

ezz = gxz = gyz = 0

Generalized plane strain elements

[…]

Autodesk Inventor now includes a new selection filter.  It can be accessed the same way as many of the other selection filters using the “right-click” menu in Inventor.  Let’s look at an example and the associated steps and results:

1. Set “Faces and Edges” as your selection filter.  This is typically the default while editing individual components.
2. Select a face, right click, and pick “Select Tangencies.”
3. Perform an operation (such as changing color) to all the faces at the same time.

 

Use the selection set of tangent faces to:

• Delete the selection set with Delete Faces.
• Assign an appearance to the selection set.
• Add or remove thickness to faces, or create an offset surface from a part face with the Thicken/Offset command.
• Copy a set of faces from one component to another (handy for tooling development)

The “Select Tangencies” option can also be used to select a continuous set of tangent edges on a component.

Use the selection set of tangent edges to:

• Fillet or chamfer the preselected edges.
• Review or check for tangency conditions or closed loops.

As an FEA analyst, you are likely losing too much of your time in CAD repair.

If you are an experienced FEA analyst, you must have come across following types of situations often while meshing your models:

“I create 3D geometries in CAD uniting together several surfaces so that the CAD modeler itself sees one unique surface; however, whenever I export it as a .sat, .stp or even binary file for Parasolid and then import it into the FEA pre-processor, I again see all those surfaces that are not supposed to be there.”

“For some parts I am extruding surfaces to solids, and for some parts I am building solids out of intersecting surfaces. All in all, it is a kind of a box structure with a hole on one side. I started importing it to GUI part by part, and as soon as I have top and bottom plate and two sides, the meshing fails. How did you exactly resolve this meshing problem?”

The FEA user community knows that most of the user interfaces available for finite element analysis are good for FE modeling only – they are not expert CAD modelers. It often happens that the CAD model created is not free from defects from a meshing perspective. The most common problems are duplicate edges, gaps, silver surfaces, unnecessary patches, etc. The problem is often more severe if a CAD model is first translated to a neutral format such as .sat, .iges, .step files before being imported into the FEA pre-processor; the defects are generated during the translation. In many other cases, the repairs made in the CAD model are not propagated into FEA modeler. The only option left is to repair the geometry in the FEA model itself, but the repair tools required often don’t exist in these user interfaces.

One-click model transfer from CAD to FEA without any neutral file format

For Abaqus users, there is great news: the Abaqus CAE pre-processor now has associative interfaces for CATIA, ProE and SOLIDWORKS.

The CATIA V5 Associative Interface allows you to transfer CATIA V5 Parts and Products into Abaqus/CAE using associative import. Materials and publications assigned to the CATIA V5 model are also transferred to the Abaqus/CAE model as material and set definitions respectively. In addition to associative import, the CATIA V5 Associative Interface allows you to directly import the geometry of CATIA V5 models in .CATPart and .CATProduct format into Abaqus/CAE without any intermediate neutral files. The following options are available with CATIA V5 associative interface: […]

Are you installing a new version of Inventor, or reinstalling a previous version? Do you have a customized User Interface that you’d like to keep? Autodesk Inventor Professional allows you to import and export customized settings to the UI with a few easy steps.

 

Application Settings can also be modified, saved, and used on other installations:

 

Thanks for reading!

Dassault Systèmes introduced a new licensing server a while ago to support licenses of all its products including SIMULIA. The server is called as Dassault Systèmes license server or DSLS. This article highlights the various installation and license management aspects of DSLS with specific focus on SIMULIA products on DSLS. It’s worthy to mention here that SIMULIA’s native FlexLM license server is still compatible with all SIMULIA products and releases and this compatibility is likely to continue in future as well.

The installation media: The best location to find latest version of DSLS media along with installation guide is the following: http://www.3ds.com/support/download/overview/

As of March 2016, the latest version of DSLS is version 6.418.2 that supports all versions of SIMULIA 2016 line of products as well as other versions of Abaqus as old as Abaqus 6.12. The media provides options to install DSLS either as a license server or as a license management tool.

The server target ID: The FlexLM license server requires physical address of Ethernet Adapter local area connection, which is usually a 12 digit numerical string such as 5S-26-0A-3W-87-0C. The DSLS target ID extraction is quite different. The media contains an executable called DSLicTarget.exe that should be launched to get the DSLS target ID for a given server. The syntax of DSLS target ID is usually a three digit character followed by a long numeric number such as CAT-427B18A3C4168A67.

The visual look of DSLS: Shown below are three visual images of the DSLS once it is installed and launched.

When DSLS is installed but server is not started

When server is started but licenses are not enrolled

[…]

Are factory or facility layouts a common part of your workflow? Factory Design Suite (FDS) allows you to import files from Autodesk’s comprehensive asset database, using either AutoCAD or Inventor Professional for your factory layouts.

Simply select the desired asset from the Asset Browser and place it in the desired location. In addition, assets can easily be re-positioned once they are loaded into a layout. This works the same with both Inventor and AutoCAD.

With the FDS interoperability workflows, once an asset is placed in your layout, it can easily be synced with all other associated files.

Thanks for reading, and leave a comment if you have any questions or additional thoughts.

ABAQUS CONFIGURATION PACKS

From a packaging perspective, Abaqus includes a user interface called Abaqus CAE and a solver that includes implicit, explicit, and computational fluid dynamics capabilities. The post-processing or result visualization can be done in either Abaqus CAE or Abaqus Viewer, which is the visualization module of Abaqus CAE. Collectively, these products are called the Abaqus unified FEA suite of products.

From a licensing perspective, the Abaqus pre-processor, solver, and viewer are available in two different configurations: Analysis pack and portfolio pack.

Analysis pack and analysis tokens

In an analysis scheme, Abaqus CAE\Abaqus Viewer are available as an independent seat. This means that the number of user interfaces that can be run concurrently depends on number of seats available in the license.

The solver works on the concept of tokens. The user utilizes a certain number of tokens depending on simulation needs. Each token has all three functionalities of solver: implicit, explicit, and CFD. Each single core non-linear job of Abaqus consumes five tokens. With a greater number of cores, the token consumption varies, as shown in the illustration below. The analysis pack is the pre-requisite configuration that includes one seat of Abaqus CAE and five analysis tokens. This means that the analysis pack is enough for a concurrent session of a single user interface and a single core Abaqus job. More user interfaces can be added in license as separate seats of Abaqus CAE. More solver functionality for multiple cores can be added as separate analysis tokens. More post-processing interfaces can be added as separate seats of Abaqus viewer.

Portfolio pack and portfolio tokens

In a portfolio scheme, Abaqus CAE, Abaqus Viewer, and the solver all work on tokens. The token utilization for a single session of Abaqus CAE and Abaqus viewer are mentioned below. The portfolio pack is the pre-requisite configuration that includes five portfolio tokens. This means that a portfolio pack can be used to run either a single core Abaqus job or one Abaqus CAE at a time. More functionalities for concurrent sessions of Abaqus CAE or multi-core jobs can be added through additional portfolio tokens as add-ons to the portfolio pack. The token consumption number as a function of multiple core jobs remains the same for portfolio configuration as for analysis configuration.

Program	Portfolio Tokens Used
Abaqus/CAE	4
Abaqus/Viewer	2

A FEW HANDY EQUATIONS FOR ABAQUS LICENSING

• T = INT(5*N^(0.422))

T = number of tokens consumed

N = number of cores utilized in a single Abaqus job

^ = power function

INT = greatest integer function that converts a real number to the equivalent integer number

This equation is used to estimate token consumption based on given number of cores. The first table mentioned in the article is a direct derivative of this equation.

• 1 QAP = 1 QAE + 5 QAT

QAP = abbreviation for analysis pack

QAE = abbreviation for Abaqus pre-processor

QAT = abbreviation for Abaqus analysis token

This equation means that a single analysis pack configuration contains one interactive seat of Abaqus pre-processor and five Abaqus solver tokens. These functionalities are sufficient to execute one Abaqus pre-processor and one single core Abaqus job concurrently.

• 1 QPP = 5 QPT

QPP = abbreviation for portfolio pack

QPT = abbreviation for Abaqus portfolio token

This equation means that a single portfolio pack configuration has five portfolio tokens inside it. These tokens are enough either to execute a single core Abaqus job or a single session of Abaqus pre-processor but not both at the same time.

Do you have any questions, or need assistance figuring out which configuration you need? Leave a comment or click on Contact Us at the top of the page to talk to someone directly.

Whether you are brand new to Inventor or a seasoned veteran, your most common task is likely navigating parts, assemblies, and drawings. The following are the picks, clicks, keys, and techniques to maneuver through Inventor’s different environments.

Mouse Commands
The four built-in functions to the mouse are:
1. Zoom In/Out
i. Rolling your middle mouse button forward or backward will zoom-in or zoom-out. By default, you pull the model toward you and push the model away. To reverse this behavior (and have the zoom behave like Google Maps) go to Tools > Application Options > Display and check “Reverse Direction” under “Zoom Behavior”. Note: Zooming by scrolling zooms toward and away from your cursor is pointed.

2. Zoom All
a. Double Clicking the middle mouse button will zoom to fit everything in view.

3. Pan
a. Clicking down the middle mouse button will pan the model.

4. Rotate (Orbit)
a. Holding the shift key and middle mouse button will rotate the view.

ViewCube

The view Cube is another method of navigating 3D space in Inventor. It is, by default, in the top right-hand corner of the graphics window.

There are quite a few ways to interact with the ViewCube: […]