Beyond Moldflow Insight

A new technology preview is live! Welcome Harmony

Over the last few years you may have gotten used to our Scandium Technology Previews, but in addition to this, we now have a new technology preview called Harmony. Harmony takes a different approach to creating a 3D part mesh. Project Harmony uses some of the components that were developed in the context of Ventus for CFD last year and differs in a few important ways from the normal meshing procedure: 

• Firstly, the mesher in Project Harmony is tolerant of imperfect CAD geometry. The Harmony mesher does not care about gaps or small intersection problems in the model. The model I used here is an STL with multiple independent components, that meshed into one part
• Secondly, the mesher uses feature based refinement scheme. With the normal Insight meshers, it's up to the user to create local mesh refinements around small features, but Harmony will do this automatically. It uses a few new control parameters "Model surface element size thickness ratio", "Model minimum feature size", "Volume mesh nominal element size" and "Volume mesh nominal layer thickness". Harmony calculates values for these parameters.

 

• Thirdly, the mesher will create a very different 3D mesh than we normally get, with near the skin a thin layer of boundary elements, that transitions into equilateral tetrahedra in the middle.

 

• Multi-body models that are brought into Harmony will be meshed as a single part and will not be meshed individually.
• Lastly, internal mesh can be reviewed using the clipping tool in the View tab. the 'Clipping' tool offers an interesting way to cut through the mesh.

Project Harmony is free for all Moldflow Insight desktop and Moldflow Flex users. Please sign up for Project Harmony  here and provide us with your feedback with this very different approach to 3D meshing.

 

The Autodesk Moldflow development team.

Many thanks to Hanno Van Raalte for this article.

 

Autodesk Simulation Moldflow Insight BETA 2015 is available!

You are well come to test 2015! You can request access to the beta by signing up here. After signing up, you will be granted access (typically within 24 hours) and you will see the Simulation 2015 beta program after you log into the beta portal.

The beta will come with installers and 2015 beta keys that will expire on Jan 31^st 2014. We wait for your valuable feedback.

Workflow to create Conformal Cooling models

This pdf is about the new calculation option in Moldflow Insight 2014 and gives the user a closer light: All steps are in a logical sequence, starting from reading in the model to the finished Cool (FEM) model including 3D channels for the conformal cooling analysis. The generation of the 3D channel solids in Inventor Fusion will be shown.
The meshing options are highlighted in order to achieve an optimal density distribution. The setting of the new CDF meshing are also explained. For better interpretability of the 3D channel results the settings are shown.

Download 2014_Conformal-Cooling-Workflow_SK1

 

Thermoplastics Bi-injection Molding Workflow

The procedure for preparation of the entire model for this process is the focus here. The assignment of the properties will also be considered in the pdf file.

Download 2014_Bi-Injection-Workflow_SK1

Modifying Fiber Parameters with CRIMS Material in Simulation Moldflow Insight

ISSUE

If you frequently use the fiber solver within Autodesk Simulation Moldflow Insight, you're most likely aware that there are several models that we use. These include the Folgar-Tucker model and the Reduced Strain Closure (RSC) model, among others. These fiber models allow the modification of several orientation model parameters, such as the coefficient of interaction (Ci) or for the RSC model, the appropriate factor to be applied. One of the most common issues here is that when you change this data and then run an analysis with a material that has been tested for CRIMS, the modified data is reset to the default.

This post will cover how to address this issue when working with CRIMS material. You don't want to potentially diminish the accuracy of your results by using the uncorrected shrinkage model, so it is important to know how to control the software to do both.

RESOLUTION

The means of addressing this is to modify a property within the material file that by default has configured the solver to recognize the default fiber parameters when using a CRIMS material. The easiest approach is to simply change the CRIMS model to use something else, such as uncorrected residual stress. That said, in Dual Domain and Midplane CRIMS is vital to accurate warp calculation. To start you'll need to access the Advanced Options so that you can edit the material file.

Once you're in the Advanced Options, you can now modify the material data by choosing the option to Edit Molding Material.

This takes you the typical Details representation of the material. The primary difference being that you can now modify the material input. From here we want to access the Shrinkage tab and access the CRIMS model coefficients.

The last step has us changing the specification for using CRIMS. Specifically the default which is set to Always (change solver parameters to be consistent with CRIMS model). We want this to be specified as the third option (unless you are concerned with the impact your fiber parameter modifications will have on the validity of CRIMS, in which case you can use the second option).

This third option, Always (even if solver parameters are not consistent with CRIMS model), will ensure the use of your fiber parameters even if they don't match the expected fiber parameters for the CRIMS model. Again, this is something that needs to be taken within context. If the fiber changes could influence the CRIMS validation, it's best to use the second option which will then default to use of the uncorrected shrinkage model if the parameters aren't consistent with CRIMS.

Autodesk Moldflow Certification

Autodesk certifications are industry-recognized credentials that can help you succeed in your design career providing benefits to both you and your employer.

The certifications provide reliable validation of skills and knowledge, and they can lead to accelerated professional development, improved productivity, and enhanced credibility.

Would you like to get certified?

For more information please follow this link.

New Tool for Removing Shrinkage from Warp in Autodesk Simulation Moldflow 2013

The new release of Autodesk Simulation Moldflow allows users to configure their warp results to remove shrink automatically.  This is a new feature, and will allow a large user base to get better results for windage predictions to determine mold cavity sizing.

It is broken down in such a way that specific shrink rates can be removed, depending on the compensation factor utilized.  These compensation factors are;

• Automatic: An estimated shrinkage rate will be applied x, y, and z directions respectively
• Isotropic: The estimated shrinkage rate is supplied by the user and then applied to each of the x, y, and z directions
• Anisotropic: The estimated shrinkage rate is supplied by the user for each direction, and then applied individually to each direction

The source of these compensation factors (for isotropic and anisotropic) can be from several areas.  They can be based off material data (in the material library, material data sheets from the supplier, etc.), as well as tested data or just a general rate to get a gauge of shrink influences to better understand what’s needed to reduce deflection.

The process is quite straight forward and provides a significant amount of information that can be utilized in determining tooling dimensions to understanding the shrink influence on the warpage.

1.)    Run an analysis through Fill+Pack+Warp in Autodesk Simulation Moldflow Insight 2013

2.)    Choose properties for the deflection plot in question, either a new plot or a default plot

3.)    Navigate to the Deflection tab

4.)    Choose the compensation option

5.)    Enter the relevant estimated shrinkage and the coordinate system to use (Anisotropic only)

6.)    Choose Apply then OK

This will now provide a representation of the deflection (in the direction you choose) with the removal of shrinkage dependent upon your configuration.  This is a great tool, and can be utilized in both the pre and post processing stages of Moldflow simulation.

Prediction of Birefringence in Plastic Parts

Weight and safety considerations are important reasons why the automotive and electronic industry is replacing glass with plastics. Another advantage of plastic components is the increased freedom of shape and the lower production costs. 

Optical plastic parts are in our daily lives. Here are some examples that you may already use today:

• automotive lightings,
• glass sunroof,
• magnifying glasses
• or display screens on cell phones

In plastic optical components you may have negative effects. Double refraction of light caused some blurring of images, displaced images, reducing of optical properties, etc ....

 More details shown in the File:

Download Birefringence

All around the Nylon 12 issue

The March 31^st explosion of a CDT manufacturing facility in Germany has caused quite a bit of commotion in the global automotive Nylon 12 (PA12) resin supply chain.  So much so, that the top brass of the top international auto companies got together in Detroit April 17^th to talk about…Nylon fuel lines, break lines, and connectors.  Amazing how such small components can cripple the massively global infrastructure that is the modern, tiered, automotive supply chain.  The Nylon 12 crisis and the search for suitable, immediate replacement resins, has been called by Moldflow technical expert Jeff Higgins, “A freak Tsunami hitting every shore.” 

“This doesn’t just hurt the Tier 1 or Tier 3 suppliers,” Jeff continued.  “Every customer meeting I’ve had this week has been more of an emergency summit, than a typical meeting.”  Jeff serves Autodesk Simulation Moldflow customers in Detroit.

Validating & Optimizing Nylon 12 Replacement Resins

Autodesk Simulation Moldflow Insight can help injection molders determine suitable resin replacements for existing PA-12 applications.  These include Nylon 6, 10, and 11 in most automotive or medical cases.   Blended resins, available from DuPont, Dow, and BASF are also good candidates.  These blends can be mixed with another electrically conductive material, which is particularly important for fuel and brake line connectors.  Those components are then electrically grounded to prevent any static discharge…for obvious reasons.

Nylon 12 has been around for over a decade, and really isn’t used much outside of the auto and medical industries.  PA12 has a unique chemical resistance to ethanol fuels and high temperatures; hence it’s importance to fuel lines.  But now that it’s suddenly gone…well you can’t ship a car without its fuel and brake lines.  And that’s exactly what’s happening...everywhere, right now.

“Hope is not a strategy,” says Moldflow Product Manager Hanno Van Raalte.  “We can simulate how the replacement candidates will perform in your existing molds and dies.  We can do it accurately, and we can do it now.” 

“Our Autodesk Moldflow Plastics Labs have been flooded with phone calls to get various PA6, 10, and 11 blends fully tested and added the Moldflow material library,” says Beth Dockstater, Moldflow Plastics Labs Project Specialist.  “We knew something was up weeks ago, and luckily the major players are already in our 2013 software material databases.”  Autodesk Simulation Moldflow 2013 is now available for download to subscription customers.  Any Moldflow users that need updated material libraries are encouraged to contact [email protected].

“There are actually a lot of ways Autodesk can help customers involved in this situation,” says Autodesk Simulation Global Account Manager Mary Forsyth.  “Once Moldflow has helped optimize the molding conditions for the new material candidate, we can then predict the mechanical performance using Autodesk Simulation Multiphysics.  With the typical replacement candidates, we actually expect the parts to be generally weaker, which can be compensated for in a variety of ways.  Some involve further refinement of the molding conditions or resin, others involve reworking the mold to thicken the part, or in extreme cases…add a stiffening rib.  Right now it’s about finding immediate, cost controlled, short term replacements.”

Autodesk Can Help

We can help a lot actually.  We have the technology; and you probably already have it installed if you are involved in this supply chain.  Be sure to log in to the Autodesk Subscription Center and update it.  Get the latest material properties.  Get your custom blends tested, and if they work, tell others.  Autodesk Simulation CFD can even help with your extrusion die optimization on those fuel lines.  Let’s get these manufacturing lines switched over fast, and right the first time, so we can all get new cars this fall. 

Then…back to making that mostly recycled, electric car in the back yard.