Great Engineering Design is about finding a solution that is not only functional but also close to optimal. For an engineer to improve a design, it is important to have easy-to-use simulation tools available that enable one to look at many “what-if” scenarios easily and efficiently. This will require effective post-processing capabilities that show, almost immediately, the consequences resulting from a design change. SOLIDWORKS Simulation Standard provides these capabilities and in this blog, we demonstrate a simple example using the Trend Tracker.
The simple connecting rod shown below is held at one end and resisting a force at the other end, acting as a simple cantilever. We define Mass and Maximum resultant displacement and von-Mises stress as the three sensor parameters to track. After running a successful static analysis, we quickly see that the part is over-designed with a high factor of safety (FOS). In this example, we also see from the stress distribution which areas of the model are not contributing to resisting the load. Another nice post-processing feature, called the Design Insight plot, also provides a similar type of information which can come very handy – especially in more complicated models with different load combinations.
Based on these results, we decide to remove some unnecessary material. We activate Trend Tracker and define this current setup as the Baseline. We remove the unwanted material by changing the geometry, another benefit of the full integration of your simulation and CAD package, and re-run the current study immediately. Within seconds, a new set of results are generated.
Under Trend Tracker, you can easily see the graph comparison of the results. With iteration two, we see that too much material has been removed; possibly resulting in excessive deformation, almost four times as much as the baseline. This is a result of the cantilever now deforming more in shear rather than bending in this example.
In iteration three, we re-introduce some material at the center like in the original baseline but at a much smaller thickness. Running the analysis and comparing the results we see that our very stiff behavior returns from our original iteration, but now with a 25-30 percent less material usage. You can continue these iterations to minimize mass while staying below your maximum allowable displacement and stress values.
Images below show the baseline and the two successive iterations with geometry changes, the stress plots, and the factor of safety (FOS) plots. Keep in mind that the value ranges in the charts are not identical, thus the relevant colors among different iterations are not exactly comparable. On the positive side, within each plot, the color distribution covers a wider range.
Finally, the three graphs comparing the mass, maximum resultant displacement and von-Mises stress are shown.
SOLIDWORKS Simulation Professional, the bundle above SOLIDWORKS Simulation Standard, among many other capabilities, also has an optimization module which takes the idea of Trend Tracker one step further and introduces automation. In this case for example, you can specify the thickness introduced in iteration three or other structural dimensions such as the size of the cutout as parameters, define a set of constraints like maximum displacement and stress not to exceed limiting values, and define an objective of mass minimization. Running the optimization module will then automatically find you the optimum solution based on the criteria you specified. Obviously, these capabilities and modules make it possible to easily find the mathematically best solution based on your criteria. It goes without saying that you should take into account other factors that may affect the overall performance of your design, such as manufacturability and the associated costs, even down to aesthetics in some designs.
As engineers, you should look at a design as your work of art and your creation. There are countless ways of creating something to satisfy the minimum requirements. As the designer, you choose how far you push to get the best design possible. In this endeavor and as a software company, we can only provide you good tools to help you along the way and make your life more productive in some specific aspects of your design. How effectively you use such tools and how you bring everything together in your design, it is all up to you.