Rapid Design Simulation Directly in Your Browser

Cloud-native solutions have become the new standard in the modern industrial era, where designers and engineers strive to focus on what matters most and maximize productivity. This is accomplished by working smarter – not harder – to build brilliant products. 

Onshape, a fully cloud-native CAD platform with built-in PDM, and SimScale, a powerful cloud-based CAE simulation software, are proud to be part of this journey, enabling seamless design and simulation simply on a web browser tab and making designing and simulation truly accessible.

Everything Starts with a Design

How would an engineer approach a design problem? As an example, say your task is to equip an industrial warehouse with shelves, which need to accommodate 30 kg of payload. The shelves have to be thin and compact, not break or plastically deform under heavy loading, and demonstrate bending resistance so they won’t fall off the mounts or interfere with the shelves below.

Using the traditional design approach, you would have to start with an existing design and figure out ways to make it thinner but still robust. You would rely on a structural analysis theory and material science to develop a few design iterations leading to a series of design candidates. Those candidates would then be manufactured before being tested and validated against real data. Such a process would likely have to be repeated multiple times until a satisfactory design is reached, which is both time-consuming and labor-intensive.

So, how could an engineer optimize their design process early on?

Cloud-Native CAD and Simulation Speeds Things Up 

Adopting digital solutions in the design process is not only beneficial but also significantly time-, effort-, and cost-efficient. More importantly, integrating cloud-native tools gives rise to a new level of accessibility.

At the CAD level, you can use Onshape to bring up any existing design from your library and begin implementing changes with your team right in your web browser. For instance, once you come up with an initial shelf design, you can share a link to the design with the rest of your team so everyone can inspect and suggest improvements. With Onshape, everything is readily available and can be accessed from anywhere.

By the time you have your design ready for testing, you’d probably start thinking about building prototypes. However, prior to that, you can run quick FEA simulations inside Onshape to test your design virtually simply by switching tabs on your web browser.

Figure 1: Onshape simulation setup.

Via a quick and intuitive setup, you can take advantage of Onshape Simulation capabilities and gain valuable design insights. Within seconds, you can immediately see the most sensitive areas of your design. In our example, the simulation results in Figure 2 show that the central part of the shelf is massively deforming by 3 mm, which is already 60% of its thickness.

Figure 2: Onshape Simulation results show shelf deformation.

There might be several reasons why this might be happening. Onshape has a pre-populated material library allowing the team to check and compare different materials with different mechanical properties quickly. You can simply change the material assignment and instantly see how this affects the deformation.

You can also run multiple studies by progressively increasing the shelf loading to study what might happen if the shelf is accidentally loaded by more than the designated weight it was designed to hold.

Figure 3: Onshape Simulation panel is running multiple simulations.

But what really makes Onshape Simulation stand out is the speed and efficiency of applying geometrical design changes to the model simply by switching browser tabs. Going back to the Part Studio tab, you can easily modify any design feature, such as increasing shelf thickness, changing its shape, and adding supporting ribs. You can then submit the changes, revert back to the simulation tab, and within seconds, see the updated results according to the applied changes.

In this particular example, you can add extra support ribs to reduce the maximum deformation and prevent failure in case of overloading. Of course, in such cases, it's important to keep the total mass of the model as low as possible to reduce material costs. For that, you can develop a parametric approach in Onshape to adjust the total number of ribs and run a series of simulations to check the maximum deformation, like in the example below.

Figure 4: Quick comparison of four alternative designs of rib supports to minimize deformation.

Based on these results, adding nine ribs seems sufficient to increase the new design’s stiffness and help it withstand failure in cases of overloading.

The same process can be repeated for any other geometric feature, material properties, and loading conditions. Onshape Simulation is a suitable tool for fast design iterations and efficient trend analysis.

High-fidelity Simulation for High-Potential Design Candidates

By now, you’d have checked several alternative configurations, tested different material properties, and benchmarked the new shelf design under different loading conditions. Using Onshape Simulation, you can select a couple of high-potential designs and switch to SimScale, an Onshape Partner app, to increase simulation fidelity all the while working in your web browser.

Designs can be easily imported from Onshape to SimScale via the dedicated geometry import plug-in.

Figure 5: Import directly from Onshape to SimScale via the available plug-in.

In SimScale, users can add higher fidelity to their qualified models. Here are some examples:

• Include 2nd-order elements to enhance the accuracy of final results,

• Add a symmetry boundary condition to further increase the mesh density,

• Model contact separation with or without friction to reach more realistic conditions,

• Use advanced material models, including elasto-plastic and hyperelastic behavior.

Say you brought a candidate model containing supporting ribs into SimScale for further investigation. Modeling the physical contact between the shelf and the mounts is crucial; excessive bending might lead the shelf to fall off the mounts, and the equipment might get damaged.

The model can be split in half, using the symmetry boundary condition, increasing the total mesh node count to improve accuracy. Using 2nd-order mesh elements and utilizing mesh refinements on regions of particular interest also add to the final accuracy, especially when it comes to bending behavior.

Figure 6: The simulation tree/setup in SimScale.

Checking the deformation results, you can identify the actual maximum deflection of the shelf (~ 11 mm). It also appears that increasing the overall load of the shelf is likely to lead to it falling off the mounts as already 30 kg are causing it to bend and separate quite excessively.

Figure 7: A high-fidelity shelf bending simulation in SimScale.

You can also visualize the maximum developed stresses by inspecting the Von Mises Stresses of the model. In our example, the maximum occurring stress seems to be 17.48 MPa. Keep an eye, however, on the material used (e.g., ABS thermoplastic polymer). Commercial ABS material might come in different compositions, affecting its mechanical properties.

Figure 8: An example of Von Mises Stress plot of shelf loading.

A Simulation-Informed Design Process

Ultimately, leveraging the power of the cloud, you can run multiple simulations in parallel and test different loading conditions and models. Combining Onshape CAD and Simulation with SimScale simulation helps get the most out of cloud-native CAD/CAE tools.

With a few clicks on Onshape, you can switch from drawing to simulation and evaluate your designs. You can then switch back to CAD, rapidly implement any design changes and re-evaluate them within the same environment by simply switching tabs. This helps develop a simulation-informed design process, drastically speeding up the whole design cycle and the generation of high-potential design candidates.

These design candidates can then be fed into SimScale for increased simulation fidelity by including geometrical, material, and contact non-linearities and complexity. This helps enrich the design process with trend analysis driven by parallel computation, spark innovation, and deep insights into the mechanical performance of the products. It also helps validate decisions with physical test replication through the web browser.

You can check the SimScale project setup and results of the shelf design example by creating a free account today!