Creo Simulate design optimization study of a rectangular beam

this tutorial will show how to do a design organization using creo simulate so we'll continue zhing our basic rectangular beam and if you remember that we said we could create some parameters and use that to drive the dimensions in the model so let's say we use two parameters here for the height and the width of the beam and we give height and width 20 millimeters initial values so that's okay and we can tie some of the dimensions to those values so if you open the section edit definition so instead of 20 millimeters I can say enter height you want to add this relation yes and for the width again you want and do want to add this relation yes so if we say okay to that sketch we can go and change the parameters so let's make it say 40 millimeters by 30 millimeters and then okay it doesn't immediately change the model size but it needs a regeneration so if you click that regenerate and the model is regenerated with the correct height angles of 40 millimeters and 30 millimeters so what we want to do now is use those height and width parameters in our design optimization we can go to simulate say save this model first and let's go to applications and simulate and as before I wanted to create a surface region here and that's what I want to apply a ton of weight so ten thousand Newtons so surface region on that area first I need to create a sketch as before select one item but I haven't got a sketch at the moment so define on that top plane and create a sketch and I want to create a simple line again from down there as sloppy as its vertical and I want to apply some dimensions to it again 400 millimeters from the base that's okay and I wanted to then define the surface that has to be split by this simple line so that's the line projection again let's say okay that so now I got two surfaces where I can apply some surface loads on so if you do a basic analysis now but just to show you that you can apply some more controls to this so if you click on auto jam you can create a mesh and that looks like a rays of coarse mesh but because pro/engineer or well creo is based on the p-type technology P adaptive technology the elements themselves can be quite large but very high order like third fourth fifth or or even higher and depending on the results of the adaptivity say note that what I can do as though maybe add more mesh size controls so geometrical reference I can do that either on surfaces volumes edges curves or points let's say create a simple sort of volume control just choosing the entire we need to create a component let's choose the entire beam component and element size let's say that's about 20 millimeters press ok and if we look at the mesh now that's a lot more refined and you can create a even finer mesh at the base where we expect the higher stress concentrations so don't want say this just now it will be automatic these we created during simulation anyway so let's say we want to apply our boundary conditions we go to home and apply a force at tip of this meme so we need to select the surface value is minus 10,000 Newtons and just a preview of that and that's shown okay and okay to that and I also wanted to apply a constraint at the base of this so let's say that I wanted to apply fully fixed boundary condition there press ok so that's applied as well and now I can start my analysis and that's going to be a new static analysis dependent on fully fixed left-hand and ten thousand Newton's applied on the right hand once the analysis is defined we can start to run the gas okay to interactive Diagnostics takes under a few seconds to complete and we can look at the results so you want to look at for me say stress and what we can see here is that the stresses are fine away from the base but at the base itself there's a some testing stress concentrations because you have a very hard boundary condition notes that's fully fixed and that's not a very good boundary conditions because it will create stress concentrations singularities and it may not reflect the actual parts fixture so to simulate what's happening there at that location you may need to do a detail model but for doing optimization study that sort of stress concentration will affect what the optimization outcome will be and we are really interested in the general beam bending stress there but these stress concentrations are really taking over the behavior from being bending to very sharp stress concentrations we can look at element shapes show element edges and see that under range if you P high or relevance there it can be further refined and as more elements are put in or more higher order elements are created value you'll have higher stress concentrations so we can do dynamic query and we can see that the stresses are ranging from say five hundred twenty-five hundred and forty and then the boundary condition here is affecting the stress in this area and if you do basic engineer has been bending theory like the force was ten thousand atoms and that's applied at a location about four hundred and fifty millimeters from the base so the moment is four point five million Newton millimeters and the y-value is the distance from the neutral axis of the beam to the top fiber let's say and I is the second moment of area for this rectangular cross-section which is 40 by 30 millimeters so by using those values I can create a stress value which is my upon I and that's around 560 mega Pascal's and that's comparing well with my APA model at the moment except where I have got these stress concentrations so what I want to do is avoid these stress concentrations in my simulation in the optimization so there's one way of doing that let's close that without saving it is possible to say if you look at the details of analysis one exclude some of the elements by taking this box but that's fine we can do that nothing here you'll need to go to refine model and under control we will select isolate for exclusion so we can define say points edges curved surfaces volumes or components for exclusion so that will say not take into account those element results in either adaptive calculations or and design optimization so we can do that with a volume for example we can say define a volume region here and then say don't use those element results within that volume so we do that under this volume region here and that can be done by a simple extrude operation and it's looking for a sketch I haven't defined a sketch I will define one on the surface so that can be a simple rectangle and I wanted to make the rectangle exactly from that corner to that corner so creating some references on the fly selecting that point and starting my rectangle from there and then going to somewhere here but again I want to create another reference on the fly pressing the Alt key and the vertex release the Alt key I can find that my rectangle snaps that vertex so that's why rectangle defined I can okay that sketch and then define how many millimeters I want to extrude that for the volume region let's say 20 millimeters in this case right so okay so that has defined a volume region now and that's similar to the surface region they have defined over there so we can use that volume region to isolate elements for exclusions so if you go to control isolate for exclusion and we can define it based on that volume which is already selected and press ok if you notice there's an excluded symbol and you can find that those controls are listed under autogen controls the first one was a size control maximum element size 20 liters the second one is a volume region which is excluded from the analysis essentially for adaptivity over-optimization so we can now go back to our model and rerun the analysis and yes that in yes it has let's close that and then we'll get the results so looking at the results at the base they're slightly modified now that are still going to quite sharp stress concentrations but when I do my optimization on this mean those that volume region will be effectively excluded if I look at the plot with element edges we'll find that that volume region is taken in the into account when the elements are created so there's a sort of group of elements that are created separately from the rest of the structure and we can also go and look at a dynamic query and you can see that around that area the value of the stress is getting about 540 mega Pascal's and on the base itself it should reach theoretically 560 mega Pascal's okay so let's try to use this model for our optimization study we can close this without saving and we need to define a new optimization design study and we want to minimize the total mass with some design limits so the design limit as we have used and the design sense 30 study can be the maximum for me so stress so maximum stress for me says that's my predefined measure I can have my own measures as well I can measure say displacements at certain points or maximum displacements and I make them as design constraints so let's go with this maximum for me say stress and then limit that to 200 mega Pascal's and I wanted to change certain design variables and try to hit this target by at the same time minimizing the mass so let's try selecting a parameter from the model the height at the moment is one of the parameters so I can select that one and try to do a simulation on a single parameter but it's possible to do simulations with multiple parameters all at the same time so let's click this button so that it inserts the selected parameter and that now is shown here as a current value minimum is thirty initial is forty maximum is 50 but I know that 50 may not be enough so let's say change that 200 and with the current value the stress values hi so let's start from the current value and initial value is the same as the current value so the optimization algorithm will look at values of the height between fourteen hundred meters to try to minimize the volume and also keep the maximum for Mesa stress the 200 so let's say okay to that and then let's run that if you look at the study status we can see where we are what parameters are currently being studied so for example at the moment that's studying in the height at 40 millimeters so the height is going to be changed so it's taking a fifty eight point nine value and six two six value and it says parameter is now feasible and then trying some other approximations near that value so it's completed analysis and it's found that sixty four point four eight essentially satisfied the phone misses criteria which is around two hundred mega Pascal's and the goal which is the the volume of the mass essentially is also minimize at the same time so let's close that and look at analysis so we can look at the fullness of stress so at the optimum value what we find is that there are still sharp concentrations at corners but if you look at the stress as away from the stress concentration area let's do a dynamic query we find that the stress around this area which should give me ruffles beam bending equations are 200 mega Pascal's so we can close that and we can close that now saving one other feature is that if you look at information and look at optimization history it allows you to sort of simulate how the optimization steps were done so we can click that to see the next shape the next shape and the next shape and the final shape and then you can accept it as your current shape just bear in mind that the optimized value 64 points something may not be sort of desirable height value you might actually choose 65 exactly with some sort of tolerance value just to make it more manufacturable so that completes our design optimization study

Channel: FEAnalysis

Views: 58,930

Keywords: Creo Simulate, finite element analysis, optimization, stress analysis, Tugrul Comlekci

Id: d4sfOXeKiB0

Length: 20min 39sec (1239 seconds)

Published: Wed Oct 14 2015