The HRS Blog – SolidWorks and CAMWorks

Every new release of SolidWorks features many enhancements and improvements, most in direct response to customer requests.  SolidWorks 2013 continues the trend, with over 200 enhancements implemented to improve performance and enhance productivity.

With so many new features and enhancements, it is difficult to cover them all.  However, I wanted to quickly highlight several great enhancements that I feel could save users valuable time and effort when post-processing or viewing results in Simulation.

Post-processing is an integral part of the analysis procedure. Analyzing results and interpreting the assumptions and simplifications that were made are important for any engineer.  Understanding this, SolidWorks has implemented several enhancements to make viewing results easier and more intuitive. Improvements in viewing results include a new transient sensor, the option to display result and factor of safety plots for selected bodies/entities, more realistic representation of results on shell bodies, and options for selecting which results to store.

First, let’s start off with the new Transient Sensor.  Available in Simulation Professional and above, this new sensor tracks results from transient studies. After running a transient study, users can graph the stored sensor values versus the range of time or frequency solution steps.

For example, in a transient thermal analysis, you can determine the min or max temperature across all steps without having to identify the specific node where the min or max temperature occurs.  In previous versions we had to plot temperature for a single step, identify the node with the min or max temperature, and then use the probe tool on the node to plot the response graph.

The second enhancement provides users with a new option when creating result plots.  “Show plot only on selected entities” lets you display results on selected faces or bodies.  In the result plot PropertyManager, under Advanced Options, you can find “Show plot only on selected entities”. 

 This new plot option will save users valuable time and effort when reviewing and especially comparing results.  Instead of hiding or isolating parts and reloading existing result plots, users can define unique plots for individual bodies.  This allows users to quickly and easily change between result plots of the individual bodies or the entire assembly.  This enhancement is definitely one of my favorites this year for Simulation and has already proved to be a valuable time saver.

The third enhancement to post-processing involves shell results.  “Render Shell Thickness in 3D” lets users display the mesh and results of shells using a 3D representation of shell bodies. For stress/strain plots, results for the Top and Bottom shell faces are shown, and are linearly interpolated across the shell thickness. Users no longer have to switch between Top and Bottom plots to compare values. When probing stress plots, both the Top and Bottom shell values are displayed. Rendering shell thickness will help users better visualize their shell models and make post-processing faster and more intuitive.

The last enhancement that I wanted to highlight lets users control the amount of results data stored in the simulation results file, reducing the file size and improving the loading speed, especially for transient analysis.

For static studies, users have the option not to store the stress and strain results in the result file (*.CWR).  For users only concerned with deflection, this option will allow studies to complete at a fraction of the run time since the stresses/strains will not be calculated.

In transient analysis, the default option for the solver is to calculate and store all the results. Now users have the option to save results only for selected solution steps for transient studies.  Note that this option is very similar to the result options that were once only available to users in Simulation Premium.

The enhancements for SolidWorks Simulation Post-Processing are just one way Simulation 2013 helps you do your job a little bit faster.  There are a myriad of other new features and enhancements not covered in this article which we will detail in later posts.  Be sure to check out our What’s New 2013 webinars, and keep an eye on this page for new articles on our ever expanding capabilities.

As more and more users are beginning to install and use SolidWorks 2013, I think there’s no better time to revisit what was presented during the launch events… as it has probably been long forgotten! Starting with SolidWorks Simulation, this blog is to act as a reminder for a sampling of our favorite new enhancements. Other articles are already in the works to present these and other enhancements in more detail, so stay tuned!

In Simulation there were three enhancements that really caught my eye, and many more to make your day-to-day experience easier. Let’s start with my top 3, beginning with a change to shell elements.

We all know (or should know) that using shell elements to represent thin members is extremely handy in keeping your solutions manageable and inexpensive. Where I felt these fell short in the past, however, was properly defining the thickness and also in post-processing the results. No longer is that the case!

Carrying forward from the ability to render beam thickness from SolidWorks 2012, comes the latest visualization tool; render shell thickness. Now you can visibly check if your shells adequately represent your geometry, and when post-processing, you no longer need to understand the difference between top and bottom. Hawk Ridge Systems Applications Engineer Dae Kim is going to be looking at this in more detail in a future post.

If you’re like me and work with assemblies in Simulation often, you probably use an incredibly coarse mesh when first defining a study. This is a method I’ve adopted to enable me to run through numerous iterations to ensure the setup is juuuust right. Once I’m pleased with the setup, only then do I start to care what my results are telling me, and it’s at that time it becomes imperative to define a proper mesh. This could be quite the arduous process in the past, because as you alter the mesh settings (using mesh controls) you were forced to remesh the entire assembly to see those changes. I used to curse the inefficiency induced while meshing parts that had absolutely no change!  Oy vey! In 2013, you can now incrementally mesh individual parts in assemblies, without unnecessarily meshing every…single…other…part! Refining meshes just got about 50X easier!

Using this is simple as well! All that is required is that you RMB on a body in the analysis tree. From there you should find the ability to remesh, as illustrated below:

Lastly, there’s a completely new way of using assemblies and multibody parts in 2013 to compliment the above. With this new tool, available in SolidWorks Simulation Professional and above, you’ll be able to transfer complex loads from larger structure to localized regions to obtain accurate stresses in localized regions. This type of analysis is referred to as a submodeling study, and it’s induced similarly to how we increment the mesh. In this case, you RMB the top level analysis name and select the “Create Submodeling Study” option.

From there you select the bodies you want to focus on. What the software will do is transfer complex global loads from the overall system, enabling you to center your efforts on a simpler localized region. This will enable more design iterations while still considering the effects from the entire system.

In addition to these three, there were some small, but welcomed changes to contacts, the organization of the simulation tree, and design studies have also been improved to allow materials to be added as a parameter. Using materials in a design study in conjunction to our expanded costing abilities makes obtaining a clear cost/benefit analysis easy to produce than ever before.

That does it for this quick wrap up! Make sure to check this space often for other articles on Enterprise PDM, SolidWorks Composer, SolidWorks, and our ever-expanding Simulation capabilities!

SolidWorks Plastics can help users quickly analyze their injection molded parts and mold process for errors well in advance of physical production. In a conventional design process, mold related problems are often found and fixed late in development, resulting in significant mold rework and cost. Using SolidWorks Plastics, users can shift more of the analysis process to earlier in the development cycle. Design changes are generally much easier and less expensive if made early and can help to ensure development is progressing in the right direction. Also, the rich feedback provided by SolidWorks Plastics, early in the development stage leads to greater freedom to explore different design ideas and innovations.

Using SolidWorks Plastics information can be gleaned about flow trajectories, mold pressure, temperature, etc. One particularly useful result is the identification of weld lines and their location. Weld lines are areas in the part when two opposing flow fronts converge. While not always an issue, these converging flow fronts can create visible lines on the part creating unwanted aesthetic defects. More importantly, they can create weakness in a part that contributes to potential failure.

The option to view weld lines is activated via a check box located in the results menu. Here is an example part with weld lines shown [Figure 1]. The injection point is located on the back left side of the part as denoted by the small red cone.

Figure 1 – Weld lines and injection point

From analyzing the feedback provided, we would likely want to reduce the number of weld lines on the vent openings to prevent possible failure in these small features.

One of the easiest ways to modify or eliminate weld lines is to change the gate location.  The rapid results provided by the SolidWorks Plastics package make this sort of operation very easy.  In the example below [Figure 2], the gate location has been changed to the right hand side of the part as denoted by the small red cone.  Based on this change, we can see that the weld lines have moved to a much more acceptable location where we can be fairly confident they will have minimal impact on our design.

Figure 2 – Weld lines based on new injection point

Recently at Hawk Ridge Systems, one of our customers, Keir B. from L-3 Communications Sonoma, contacted the technical support team for some help with a validation example that he set up in order to better predict what would happen with a more complex real-world model. Keir wanted to make sure he was using conditions that would match the hand calculation he performed in order to gauge the discrepancy (as in any scientific field, the more evidence you have, the better). We, of course, were happy to help. Keir wrote:

“In this study the key result I am trying to determine is the force generated between two parts made from two different materials as they expand or contract due to temperature changes. The forces are created because of the geometric mismatch caused by the different rates of thermal expansion.”

The original model, shown below, consists of an Alloy Steel frame which has a thin 6061-T6 Aluminum plate bonded to it at two ends. The whole unit is cooled from a room temperature of 20 °C down to -55 °C, or -67 °F for us Americans (thank goodness for SolidWorks’s built-in unit conversion).

Because Aluminum has a higher thermal expansion coefficient than steel, the plate should shrink more than the frame, creating a tensile force in the plate due to the bond between the two parts. We can predict the expected deformation δ of the plate using the thermal expansion equation:

…where L is the original length of the plate, ΔT  is the temperature change, and a is the thermal expansion coefficient. Because we actually have two materials in this example, the equation can be simplified by analyzing the plate only and using the difference between the two material properties. Again, Keir wrote:

“Steel expands (or contracts) at 1.1 x 10^-5 /°C; Aluminum expands (or contracts) at 2.4 x 10^-5 /°C. Therefore the difference of 1.3 x 10^-5 /°C will cause a force to be generated within the structure proportional to the amount of temperature change.”

Using this assumption and throwing the appropriate values into the equation, we get:

Finally, we can use this deformation to calculate the tensile force  on the plate:

…where A is the cross-sectional area of the plate and E is the elastic modulus of 6061-T6 aluminum. We get:

So, how does SolidWorks stack up in comparison? To check, we will first want to make sure our study setup has the exact same assumptions that we are using for our hand calculations. In this example, that means analyzing the aluminum plate only and changing its material properties to use the net thermal expansion coefficient of 1.3 x 10^-5 /°C.

In our study, the part is restrained so that the end faces (where the plate is attached to the steel frame) cannot displace lengthwise. Because the part is in static equilibrium, the tensile reaction force at end of the plate will be equal to the required force value we obtained from the hand calculation.

After running the study, we can use the List Result Force tool from the Results folder to obtain the reaction force:

How do you like that?! Thanks to very simple geometry and a good mesh, we get a lengthwise reaction force of 9,750 lb, which matches up exactly with our hand calculation. The reason is simple: SolidWorks Simulation is using the same equations to get its solution as we are – after all, that’s why all the same values need to be entered somewhere in the software, be they the part geometry or material properties!

Of course, the real-world result from a physical test would differ somewhat from this simplified case, because we discounted the steel frame which in reality will also displace. That’s why the original model would not be a good comparison to the simplified hand calculation. So, the moral of the story is: make sure any study you create for comparing to hand calculations has the same conditions and assumptions! Do your homework, and you should get a warm, comfy, reassuring result each time.