Follow Along: Objectives & Constraints

In this follow-along, we are going to be reviewing defining objectives and constraints for our field optimization, optimizing the Voronoi midsole of this midsole and outsole combination that we see on the screen. So far, we have already created our parametric FE model using our Parametric FE component and our Regular FE component from our volume meshes that were imported in our geometry in the import section above.

We’re going to begin by choosing our optimization objective. I can do this by coming to my responses and choosing Optimization Objective. From here, I can double click inside of my Design Response block and I can choose Structural Compliance Response. We are then going to choose two load cases that we will put in this load case input here. These two are going to be a force applied downward on our midsole here and a displacement restraint placed at the bottom of our outsole here. First, though, we are going to go about defining our force. I can find our Force block by coming to our simulation Tab and going to our boundary conditions. For our force, I’m going to double click on our input and I’m going to select FE Boundary by Body. With this block, I’m going to then select our midsole mesh nodes as my entity, and for my body, I’m going to use our leg variable above in our geometry and import section. Choosing this leg variable is then going to choose the nodes where our midsole and our foot interact, giving us our foot imprint for our force here below. For a force vector, then I’m going to use 0 and 0 in our X and Y direction and then -500 Newtons in our Z direction. Once I hit enter, I can see our yellow glyphs indicating our force in the negative Z direction. To finish our force, then I’m going to right click and say make variable and just name this Force.

Next, I’m going to go about creating my displacement restraint below my force. To do this, I’ll come back to our simulation Tab and I’m going to go over to my boundary conditions again and select Displacement Restraint. For my boundary, for my displacement restraint, I’m going to double click and select FE Boundary by Flood Fill. For my mesh, I’m then going to choose outsole mesh nodes for my entity, and for my origin, I’m simply going to click into one of these tabs. Then I’m going to see this slider appear on my screen and I’m going to drag it as close to the bottom of my midsole as I can. When I let go, I can see the glyphs that are highlighted by this boundary by flood fill, and I can see we have a few too many. So I’m going to adjust my angle here to say 20 degrees, and now I can see I have all of the nodes at the bottom of my mesh selected. When I hover over this, I can then see that I have my displacement restraint set up at the bottom of my shoe while the yellow force is applied to the top of my midsole. My final step here with my displacement restraint is right clicking, making it a variable, and naming it Displacement. Our final step here is just going to be taking both of these and I’m closing them by hitting spacebar and dragging them into our boundary conditions here. To finish our optimization objective, I’m going to right-click, make it a variable, and name it Optimization Objectives.

Now that our objectives are done, I’m going to close this block and we’re going to move on to our final block where we are going to be defining our constraint. To define our constraint, I’ll come back over to our optimization tab to our constraints, and I’ll choose Design Response Constraint. For a response, then I’m going to double click and select Volume Fraction Response. When looking at my optimization object here, I know that the only region that I want to minimize the volume of is going to be our parametric FE region here. To select this region, I can then double click in this block and choose FE Region by Body. I’ll then choose my corresponding mesh, my midsole mesh, from my entity, I’ll use cells, and then for my body, I’ll scroll all the way to the top and use midsole from my first section. Now that that is run, I can see the selected body on my screen if I visualize this block, and for my value, I’m going to say 0.2, meaning I want my final optimized result to have less than 0.2 of the original volume of this midsole. To finish this constraint, I’ll then right-click, say make a variable, and name this Volume Constraint.