Why You SHOULD be Running Dynamic Simulations
Let’s discuss the difference between the linear solver and the dynamic solver with a case study. Take the example of an engineer slamming his head on his desk after getting poor simulation results from his linear solver.
In scenario #1, the engineer lightly places his head on his desk then proceeds to slowly press down with his body weight. The force value, F, represents the maximum amount of force he can transmit through his neck.
In scenario #2, the engineers head starts a distance of 2 feet from his desk. The engineer proceeds to accelerate his head towards his desk with the aforementioned force value, F. After he comes into contact with the desk, his neck continues to transmit the force until his head comes to a complete rest against the surface.
Now, in both scenarios, the engineer’s neck transmits the same amount of force, F. However, the second scenario will produce higher levels of cranial stress at specific instances in time. The higher stress is related to momentum. The engineer recognizes this and proceeds with scenario #2 until the desired level of masochistic indulgence is achieved.
If we were to simulate these events, design scenario #1 could be adequately achieved with either the static solver or the dynamic solver and the results would be the same. However, if we were to run scenario #2 with a static solver, we would get the same result as we would with scenario #1. Obviously, the static solver has limitations.
The linear solver only sees the last moment in time; when things are at rest. Thus, we have two data points, the beginning and the end.
On the other hand, the dynamic solver is aware of the time in-between the beginning and the end. As a result, we are left with a much more complete picture.
For a moment, let’s sidestep the slamming head on desk approach, as this practice is no longer necessary. Let’s use the example of a cantilever beam with a weight of one hundred pounds suspended from the end.
For the linear study, let’s consider the case of loading the end very slowly. The results of this simulation are shown below.
The maximum displacement is 58 mm.
For the dynamic study, let’s consider that the weight will take .05 seconds to reach its maximum value of 100 pounds and will then level out. The maximum displacement results of this simulation are shown below.
The maximum displacement is 93 mm. This is an enormous jump from 58mm. Obviously, we’d want to study the dynamic simulation results over the static.
Tech Tip: Network Slowdown
Does SolidWorks sometime feel like it’s working at a turtle’s pace? The problem might stem from being connected to a network!
Working on a network is great, and in today’s age it’s basically required. Unplugging from the network could solve a lot of issues, but usually isn’t feasible. The problem is that so much stuff is looking to the network it can sometimes slow down SolidWorks. There can be a ton of reasons for this, some can be fixed! Here’ are a few tips to make your performance a better while working with SolidWorks.
- Don’t work over the network!!! One of the biggest slowdowns you can cause in SolidWorks is by trying to work with files that are located on the network. If the files aren’t on your local computer, every time you open them, temp version of them are made in the directory they’re opened in. Every change you make has to get written to those. Every time you save the main files get written to. All of that going over the network is going to slow down SolidWorks. Copy files locally to avoid those issues.
- Backup/Auto-Recover: You should not have these locations be on the network. If these locations aren’t local, SW will again be constantly working and writing over the network and slow down. The backup option to put the backups in the same place as the original file can double the issue if you’re working on files over the network as well.
- SolidWorks Search: The SW Search is useful, but if you don’t use it, turn it off. If you do use it, make sure to set the indexing to “only when the computer is idle.”
- News Feed: Turn off the option in the general area of the options to “Show latest news feeds…” It may be minor, but it’s one more thing to slow down SW.
- Stop Streaming: Turn off things like streaming audio, unneeded web pages, and any other non-essential programs. The less trying to fight for resources the better.

- Stop the CPU War: Everything you’re running on a computer is constantly fighting for you CPU. When you’re on the network, even more things are fighting for it. If possible, dedicate a CPU core to SolidWorks. Windows defaults everything to the first core, once that’s full, it’ll start using other cores. Most of SW can only use one core, so the more it’s trying to fight with the slower it will run. If you can dedicate a core, it will reduce the chances of a slow down.
Fully Define Sketch
We have been preaching to you forever about the importance of fully defining your SolidWorks sketches. Now that you have (hopefully) accepted the reasoning behind the recommendation, today’s tech tip will help you reduce the time it will take you to accomplish this task.
Introducing, the FULLY DEFINE SKETCH command. Well it was actually introduced several years ago but it may be new to you.
The Fully Define Sketch tool calculates which dimensions and relations are required to fully define under defined sketches or selected sketch entities. You can access Fully Define Sketch at any point and with any combination of dimensions and relations already added.
To fully define a sketch:
1. Edit a sketch.
2. Click Fully Define Sketch (Dimensions/Relations toolbar) or Tools, Dimensions, Fully Define Sketch.
3. Set the options for relations and dimensions in the Fully Define Sketch PropertyManager.
4. Click the green check mark.
That’s it. To simplify it even further, you can program a hotkey to invoke the command. Now that you know how simple it is to define your sketches, there is really no reason not to. Try it. You might like it. I know your sketches will be happy.
Don’t Ignore That Little Green Flag
There is a setting on the workflow states in EPDM that is easy to overlook but can drive you nuts while troubleshooting. That setting is “Ignore permissions in previous states.” In 2011, it is the green flag icon on the State Box. (Previously the icon was a hand.)

Why this setting can be troublesome.
If this flag is not set there will be circumstances where permissions set at a particular state are not followed. This particularly happens when a permission was granted at an earlier state but removed at a later state. Let’s go through an example. I’m going to use a simple workflow and explain what happens with “Read file contents” for two groups.
Scenario 1:
The “Ignore permissions in previous states” flag is NOT selected for any state.
Permission: Can “Read file contents”

With this setup someone in Sales should be able to see any file that is in the Released state but not in any other state.
A document was added to the vault and is currently in the Initiated State.
This is what an Engineering user sees: This is what a Sales user sees:

So far everything is as expected.
Change State was initiated on the document and it was sent to the Released State.
This is what an Engineering user sees: This is what a Sales user sees:

At this point, this is what we planned with our workflow.
Now, though, let’s Change State on the document again and send it to the Under Editing State.
This is what an Engineering user sees: This is what a Sales user sees:

Wait a minute! The Sales user is NOT supposed to see files in Under Editing. So what’s going on?

It has to do with that little green flag. Because we did not set the “Ignore permissions in previous states”, the Sales user can see the file when it is Under Editing because they were able to see it in the previous Released state.
Scenario 2:
Let’s try this again with a new file but this time we’ll set the “Ignore permissions” flag in all states.
This is what an Engineering user sees: This is what a Sales user sees:

Change state to Released.
This is what an Engineering user sees: This is what a Sales user sees:

OK, so far, so good.
Change state to Under Editing.
This is what an Engineering user sees: This is what a Sales user sees:

This time, this is exactly what we wanted to happen.
By turning on the “Ignore permissions in previous states” flag, the permissions set for each state were followed exactly as we set them. So don’t ignore that little green flag!
SolidWorks 2012 Announced
Hi all – read all about it. SolidWorks 2012, the 20th release of the software, announced today. We can’t wait to show it to you at our launch events. Some very nice comments and videos from customers.
What’s Driving Your Simulations: Part Duex – Flow Simulation using the HVAC Module
In Part One, we discussed the parametric design of a solar thermal collector. In this part, we’ll take a look at the HVAC modules capabilities in handling advanced radiation. Before we begin, let’s discuss the physics of radiation.
On a simple level, radiation from a heat source (any heat source) travels in waves. These waves have different wave lengths depending on the temperature of the heat source. So, a computer screen will have a different radiation spectrum than a fire or a desk lamp.
When radiation strikes an object, some of the radiation will be absorbed, a fraction will be transmitted, and the remaining radiation will be reflected. Any radiation which is absorbed turns into heat. Any radiation which is transmitted passes through the object. And reflected radiation is reflected back to the environment.
For a particular material, the ratios of absorption, transmittance and reflection are different depending on the wavelength. So, graphs of these ratios against the wavelength spectrum are required in order to get accurate radiation properties for a particular material.
Let’s relate this information to the solar collector. Radiation transmits through the solar panel glass and is absorbed by the pipes and collector’s conducting walls. The heat is then transferred to the water passing through the system.
At this point you might be wondering why we have glass on the system. A portion of the sun’s radiation will be reflected back as a result of the glass. Wouldn’t we collect more radiation on the pipes if the glass wasn’t there? The answer is YES. We would collect more radiation on the pipes if the glass wasn’t there. However, the system is more complicated than that. Every heat source radiates at a particular wave length. And, the ratios of absorption, transmittance and reflection are different depending on the wavelength. So, as it turns out, the glass transmits most of the radiation from the sun and absorbs and reflects most of the radiation from the pipes. The glass traps the heat in the system. It’s the exact same reason your car gets hot in the sun.
Okay, let’s simplify our model for simulation.

Now, let’s create a flow study. For this project, we’ll specify an external analysis which will have an internal fluid sub-domain for water flowing through the pipes. For the first go around, we’ll keep the model simple and exclude cavities without flow conditions. This will eliminate any convective effects from air within the box. We’ll also introduce radiation, gravity and heat conduction in solids.
Okay, this is where we’ll need to take a closer look at our solar radiation options and make some decisions. Radiation is not simple. From the general settings, we can see that there are a lot of radiation options. However, SolidWorks does a good job of making it as easy as possible to get setup.
Environmental Radiation – By selecting this option, we are considering radiation effects from the environment which we define at a specified temperature.
Solar Radiation – By selecting this option, we are considering radiation effects from a single source.
With this option selected, we can specify a radiation source by its location and intensity.
We can also take the suns radiation into account, as specified by “Location and Time.”
Let’s take a closer look at “Location and Time.” For SolidWorks to calculate the suns effects on the panel, SolidWorks needs to understand the suns orientation relative to the collector. That’s why we specify the latitude, date, time, zenith direction, angle measured from north to, and angle. The first three values seem obvious, but zenith direction, angle measured from north to, and angle might not make sense to the layman.
Zenith direction – This option specifies the highest direction in the sky. Directly above you. Up. In this case, I’ve specified a custom coordinate system and chosen the y-axis.
Angle measured from north to – This option specifies the orientation within your system which you would like to relate to north. In this case, I’ve specified a custom coordinate system and chosen the z-axis.
Angle - This specifies which way north is relative to “angle measured from north to”. In my case, I’ve kept this value at 0 radians which means my “angle measured from north to” is north as well.
For this simulation, I’ll also specify absorption in solids.
Okay, this is getting long and I’m sure your head hurts. We’ll discuss further in part Trois.
pdf in 3D
Everyone knows that .pdf files are a great, simple way to communicate documents electronically. Most SolidWorks users are aware that you can create .pdf documents from SolidWorks. Did you know you can create Adobe PDF documents with embedded 3D models? You can convey complex 3D designs to all of your partners and clients no matter what tools they use. This allows the recipient to do things such as rotate, pan and zoom the SolidWorks model inside the pdf document. They can also do things such as change background colors and display styles as well as several other functions.
Now a simple right click inside of the Adobe Reader with the .pdf open and you are working in 3D.
Remove the Toolbox Flag
When Toolbox parts are saved out as separate, unique files, they retain information about their parentage. It’s called a Toolbox flag. In the past it usually didn’t cause a problem but in SolidWorks 2011, a setting was added that could potentially cause your saved parts to be replaced with standard Toolbox components. You can tell if a component has a Toolbox flag by the bolt icon showing in the Assembly tree.
The new setting tells SolidWorks to always look in the Toolbox location for Toolbox components. Uncheck this setting and SolidWorks should find your parts correctly.
The best solution, though, is to turn off the Toolbox flag on your components and turn them into regular SolidWorks parts. There is a program that is installed with SolidWorks that will do this.
- Go to C:\Program Files\SolidWorks Corp 2011\SolidWorks\Toolbox\data utilities and look for sldsetdocprop.exe
- Double click on the executable file.
- Make sure the Property State is set to No under Set Document Property.
Check Part Files.
Select either Add Files… to select individual files or Add Directories… to select an entire folder. - Click Update Status.
- To verify the status of a file after running the program, select a file and click Show Selected property.

If you have any questions, please give Tech Support a call at 763-560-8600, Option 4.
Tech Tip: Fighting With Mirrors
Mirrors can be your friends and your enemies both on the wall and in SolidWorks. If you’re making a part that’s symmetric, mirroring can save you a lot of time building matching features on both sides of the part. However, if you don’t do things correctly it can lead to lots of nightmares.
The biggest complications can stem from the base sketches of your part. Mirroring in a sketch is handy to create symmetric entities, but why not just mirror the feature instead? As a general rule, the more entities you have in a sketch, the more chances you’re giving your model to go wrong. Everything might be symmetric when you start, but if you go back in and edit something later it could all blow up.
Another headache can be due to how you’re defining your features. Mirroring “Blind” features is usually no problem. If you start using more advanced definitions like Up to Vertex, Up to Surface and the like the mirroring the feature may not work because it can’t find the appropriate geometry or extends to the wrong place to really be a “mirror.”
Some features like fillets and chamfers are really picky about the geometry they’re made with. If you try to mirror them, and the faces they’re being mirrored to aren’t exactly the same, they will likely fail.
There are so many ways to have issues! Why not just skip all of them? The solution: Mirror Body. Skip all the headaches of trying to mirror sketches and features and just model half your part, mirror the body and be done. Less sketch entities, less features and less hassle. If you want to ensure total symmetricity that’s your best way to go.











