SolidWorks SimulationXpress…it’s FREE! Use it!
(there’s a complimentary bonus link at the end)

What can SimulationXpress do?

1. Part analysis
2. Stress analysis
3. Optimization analysis with one variable and criterion
4. Analysis management using Simulation study tree
5. Isotropic materials
6. Uniform pressure and force on faces
7. Fixed restraints on faces
8. Stress contour plot-equivalent (von Mises) stress
9. Deformation plot
10. Factor of safety calculation and plot
11. Generate reports
12. Publish SolidWorks eDrawings of analysis results
13. Animate and save as AVI

Compress it…

Bend it…

Twist it…

Evaluate Factor of Safety…

Optimize it…

You have created a Simulation study of a fairly large assembly.  It has a mixed mesh – Solid elements, also Shell elements, maybe also some Beams.  You are relying on the GLOBAL CONTACT – BONDED to tie together all the mesh bodies of similar type.  You spent maybe 40 minutes, at least, creating the BONDED contact conditions to tie the dissimilar mesh elements together.
 And now when you try to run the study, you get the failure message, “Zero or indefinite stiffness matrix”.
 Ugh.  That means that at least one component is not correctly bonding to a neighbor, and so is free-floating.  But which one?  Since the study won’t run, you can’t display the displacement plot, and see which part(s) are flying off the screen.  How to diagnose this – without wasting the entire morning?  There are two ways I approach solving the problem, and they both use the study Property option, “Use Soft Springs to Stabilize the Model”.
1:  Moving
Sometimes you can simply turn ‘soft springs’ on, and run the study again.  About half the time, I find that the study will now run, (and produce a warning message, that very large displacements were detected).  Tell it to continue running the study anyway, as-is, without turning on the large-displacement flag.  Then, when you plot the Displacement results, you might very well be looking at an empty screen, or you might see that one (or more) parts seem to be missing from the plot.  They are not missing – they simply went flying off the screen.  Set your Displacement scale factor to be wicked small, (think many leading zeros), and then animate the displacement plot – and you’ll see at the start of the animation, which parts are un-tethered, and in which directions they are free to wander.
A cool and easy trick.  Except that, I did say above, I use this trick “about half the time”.  Because the other half of the time, the applied loads might act directly on the under-restrained parts, in the same direction that they are free to move, and then the “Soft Springs” do not supply enough stabilization.  What to do then?
2:  Shaking
The second approach is to Shake the assembly, instead of moving it.  Create a new Modal Study, (this will require the Simulation license to be Simulation Professional or higher).  Set the Modal Study Properties to only ask for the lowest 2 mode-shapes, or maybe 3, but no more.  (this is a diagnosis, not a true study, so you want it to run fast).  Then you copy all your Restraints and Bonded conditions into the new study.
Wait – I did NOT say to re-create all your Restraints and Bonded contacts.  I  said “COPY” them.  This is a “tip within the tip”.  A lot of people I encounter still don’t know you can do this.  If you activate your first, “real” study, you can then select the folder for your Restraints, and DRAG that folder down to the row of tabs at the bottom of your screen, and DROP it into your new Modal study.  Done.  So creating this Modal study to diagnose your problem should take, like, 30 seconds tops.   You do NOT have to copy over your system of loads – just the restraints and bonding, because we are not going to ‘push’ your assembly in any particular direction, we are instead going to vibrate it in-place.
But, you DO still have to turn on the “Soft Springs” option to stabilize the model.
Ok, now you RUN the Modal study.   Because the underlying equations of the Modal study are being solved differently than a Static study, the problem will generally solve O.K. even with under-supported parts.  And, when you activate the plot for the lowest 2 or 3 mode-shapes, each one should show you some rigid-body motion, (and remember, it could also be a rotation!), of the part or parts that are un-tethered.   Animate the model-shape plot, and it will be patently obvious which parts are walking away, and in which directions.
Important caveat: The Modal Analysis method of diagnosing your problem, will NOT allow you to create sliding or intermittent Contact via the “No Penetration” gap elements.  If your problem also has that kind of Contact in it, you need to either ignore that contact for the purpose of diagnosis, (which will too sloppy, and you’ll have to ask for more Mode Shapes –  ignore the responses you know are not ‘real’);   Or, you could replace the Bonded contact, with either an Elastic Support, or a Spring Connector.  With either of these, make the Normal spring stiffness pretty high, but the tangential spring stiffness very low – and you WILL have over-supported the selected faces a little bit.  But again, you’re just looking for which parts want to walk away, not running the ‘real’ study yet, so we can throw a few darts.  And if the problem produces NO rigid-body modes when you’ve replaced the Gap elements with springs, then you know for sure that the Contact conditions are the real problem.
One of these two methods should solve the “Zero or Indefinite Matrix” problem for you, just about all the time.

Shell Edge to Beam Bonding

The bonding of shell edges that belong to surface or sheet metal bodies to beams, commonly used to simulate gusset plates connecting beams, is supported through manual contact set definitions.

Render Shell Thickness

Reaction Forces for Beams

SolidWorks Simulation- Restraint Preview Icons Video

Solidworks Flow Simulation can be used to study the fluid flow and heat transfer for a wide variety of engineering equipment. In this example we use Solidworks Flow Simulation to determine the efficiency of a counterflow heat exchanger and to observe the temperature and flow patterns inside of it. With Solidworks Flow Simulation the determination of heat exchanger efficiency is straightforward and by investigating the flow and temperature patterns, the design engineer can gain insight into the physical processes involved thus giving guidance for
improvements to the design.

Boundary Conditions Solidworks Flow Simulation Tutorial help you learn something

A boundary condition is required anywhere fluid enters or exits the system and can be
set as a Pressure, Mass Flow, Volume Flow or Velocity.
1 In the Flow right-click the Boundary Conditions icon

 Flow Simulation solidworks tutorial

This First Steps tutorial covers the flow of water through a ball valve assembly before and
after some design changes. The objective is to show how easy fluid flow simulation can be
using Solidworks Flow Simulation and how simple it is to analyze design variations. These two factors make Solidworks Flow Simulation the perfect tool for engineers who want to test the impact of their design changes.

A customer requested help creating the intersection between a loft and a sweep. He is working on a hairdryer and had already created the profiles to generate the lofted solid.

Why can’t we all just get along? Trading files back and forth is an issue that plagues engineers often. However there are some things that can alleviate the problem. Take exchanging Pro/ENGINEER parts and assemblies with SolidWorks. This works relatively well with the robust feature sets that SolidWorks offers for either handling the Pro/ENGINEER features natively as well as handling edits with explicit face manipulation.
First, let’s look at the issue of viewing Pro/ENGINEER files. SolidWorks eDrawings software, a free download, allows users to view native SolidWorks, DWG/DXF and Pro/ENGINEER parts and assemblies. If you have the eDrawings Professional package, you can also measure and markup these files, and send them to your colleagues, customers or vendors to review and markup as well. Finally, you can also download eDrawings Publisher plugins for a variety of other CAD programs, like Pro/ENGINEER so save parts, assemblies and drawings to the eDrawing file format. This publisher also works with PTC’s OneSpace Explicit modeling package (The old ME30) as well as many other CAD programs.

Once we have viewed the file in eDrawings, we can then open the file in SolidWorks for editing. SolidWorks can open the most current versions of Pro/ENGINEER Wildfire and for the latest specifics, I would encourage you to take a look the online SolidWorks help for Assembly import and Part Import. In the video embedded below, I run through several options of importing and exporting Pro/ENGINEER files with SolidWorks.

In the first part of the video, we open the Pro/E assembly in eDrawings Professional, and mark it up to indicate a design change is needed. In this case we need to change the length of the link on a toggle clamp. Once this is identified, we open the Pro/E assembly in SolidWorks. We are presented with a dialog box asking us how we want to import the assembly.



For an assembly we either have the choice of bringing in the part’s feature history or to use the BREP (boundary representation) of the parts. I choose the BREP as it is the most reliable and will bring in the most accurate representation of the solid model into SolidWorks. Plus, I get the opportunity to import mates (constraints in Pro/E). If you use the feature import, this is not a capability, however, you can import a part later with features and then replace that new part in an assembly that you have already imported.
In the following image, you will notice that the assembly comes in with all mates and material properties. Without even doing anything, it looks great. I am using SolidWorks 2011 and turned on the integrated PhotoView 360 preview and it looks fantastic, see below:


Here you can examine the mates and dynamically move the clamp as you would expect to to move. You can even turn on dynamic collision detection to see what the true range of motion is. Now we need to make the design change lengthen the link. Simply click on one of the links and choose “Edit Part” which allows you to change the part inside of the assembly model. Since I imported the part with no features, I will use the “Direct Editing” tools to lengthen the link. After making the direct edits to the link, and then testing the dynamic motion again I notice my range of motion is now limited and I need to change the clamp-base component, so I employ the direct edition tools again.
I should also note, that you can save out a versioned Pro/E assembly after you make your changes in SolidWorks, to share with other Pro/E users. Check out the video below for a full run-through and please add comments on your experience with this!

Defining the material For SolidWorks Simulation Tutorials

SolidWorks is, first and foremost, a 3-D modeling tool. Look in the tutorials folder for a SolidWorks model named “glass.SLDPRT”. When you open it, it should show a wine glass, as in Figure 1. This is the model we are going to study in this tutorial. Save a copy to your Charlie account.

If you wish to practice your modeling, part of a technical drawing of this wine glass is included in Appendix A. Units are in millimeters. This should be enough information to draw your own.