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rorythornton

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About rorythornton

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  1. Hi Abdessamed, I don't quite get you mean by this. I am looking to compare the Torque deflection curve of different versions of the magnet arrangement, created by varying the different inputs (Diameters, positions, angles etc): How do I apply this macro to my solving scenario in fux so that it can be exported to hyperstudy to do DoE on it to get the optimum shape curve? Is it possible to apply a 5th order line of best fit to the curve using this macro? Thank you for your continued help with this Rory
  2. Thank you Abdessamed, I am trying to evaluate a nominal run, but I am now getting these errors: I believe this is because I am using a sensor (Called Torque) as my coupling file output, as opposed to an I/O parameter that the tutorial tells me to do. However, I did this because I am not sure how to turn the Torque sensor output into an I/O parameter. When I try to do it, it wont work unless I do something with the table highlighted below... I don't know how I am suppose to fill out this table if I want all the values of the torque/deflection curve to be used The tutorial example only creates this to save only the y component of the sensor, but I what the whole output to be used. Is the error im getting above to do with what I am defining as my simulation output? If so, how do I fill out this I/O parameter table? Many Thanks Rory
  3. Hello I have generated the GOT-It coupling file and I have used it to define the model. But when I click on "import variables" (step 3 from "HyperStudy Project" table in tutorial), I get the following error I have tried putting the coupling file and creating the study in different locations on my computer, but I keep getting the same error Do you know how I can fix this? Many Thanks Rory
  4. Hi, I have just checked these. I had used the parameters to define 2/3 points required for each circle. I have changed it so that all 3 were defined using the geometric parameters and now the model works properly. Thank you for spotting this! Kindest regards Rory
  5. Hi, Thank you for this, very helpful. I have set up a model of my magnets using a Geometric parameter for each of the inputs I described above to drive all the dimensions in the model so they can be adjusted during the DoE. However, when I adjust the variable that controls the distance from the centreline the magnets rotate from (Indicated with red arrow in diagram below), from 30 (current value) to 60 for example, Altair Flux freezes and I have to reopen the simulation: This variable (Called RD in the project) is linked to all the sketches used to create the magnets and compressible region. I have played around with all the other variables and they work fine, it's just this one that causes a problem. I have attached the project folder. I would really appreciate it if you could have a look at it to see what the cause of the problem is, as I am unable continue until I have resolved this. Thank you in Advance Rory ROTATING_MAGNETS_OPTIMISER.FLU.zip
  6. Hello, I have modelled the following arrangement of permanent magnets in Flux: The four smaller disc magnets (with white lines) are stationary The two larger ones (with black lines) rotate together about the centreline shown From this simulation, I have plotted a torque deflection curve for the different position of the rotating magnets A fitting curve is then applied to this and the equation of that line gives me the stiffness coefficients produced from the magnetic interaction I am looking to optimise the design of this to give me specific stiffness characteristics. I have read about something called "Design of Experiments" that allows you to input a range of values for multiple variables into a model, define the output variable that you want and then run a simulation that finds the permutation of inputs that yield the required output (or the closest achievable). My question is: Does Altair Flux have any Design of Experiments tools in it that can allow me to do this? The input variables for my model are: Disc magnets size Disc magnets material Radius of magnets rotation from centreline Max angle that the rotating magnets can deflect My required output is: A Torque deflection curve with a 3rd order line of best fit that has the largest x^3 coefficient while having lowest x coefficient Aka, a torque deflection curve that is as close to a y=x^3 graph as possible Any advice on this would be greatly appreciated, even if it's just ways to run a single simulation with as many different input variables as possible to reduce the total number of simulation I need to do to optimise the design. Many Thanks Rory
  7. Hello Great, Thank you! I will give it a go Kindest Regards Rory
  8. Hello I have modelled two permanent magnets, one fixed (disc) and the other translating away from the first (spherical) in the z-direction. Please see below: From this I plotted the force acting on the spherical magnet in the z direction at each deflection step. My results correlate quite well to experimental data, but the simulation forces are all slightly smaller than the experimental. My first question is: would creating a compressible region surrounding these magnets improve the accuracy of the simulation? I quickly tried to model and mesh one, please see below: As you can see, the mesh is very coarse I used the automatic mesh generator for the compressible region and I cannot figure out how to manually make these elements smaller It doesn't even look like the mesh in the compressible region has been created to interact with the meshes of the two magnets inside When I ran the solution, the results were much worse. They were all over the place, with some force values not making sense I assume these results are due to how coarse the compressible mesh is. However, without it, surely the mesh inside the infinite box must have similar sized elements, so I don't understand how having the compressible region has made the results worse..... The reason I originally modelled it without a compressible region was because I followed the linear actuator tutorial, which does not require one. But another simulation I've been running, involves rotating magnets and I can't even get that to run without a compressible region. As this confuses me, my second/third question is.... What criteria requires the use of a compressible region in a simulation and in what instances should you avoid using them? Many Thanks Rory
  9. Hi Abdessamed, Thank you for this, very helpful. One particular section of the "2019 Altair Flux - User Guide" that I found useful was the one on "Examples of criteria to validate a mesh" (Page 219). This lists out checks that can be done on the simulation results to validate the accuracy of the mesh. Examples are: Checking that the reaction forces balance the input loads Looking for cracks in the field lines generated within a single region These are very useful as they dont require a comparison of the simulation results to an experiment or test. Are there any other ones that you (or anyone else reading this) use to help sanity check your meshes? Or alternatively, is there any good literature on this subject? Moreover, other FEM softwares have in-built mesh checking tools. For example: Element error/quality checking (Distorsion checks for example) A computed model confidence % calculated while solving the solution Does Altair Flux have any kind of checker or convergence tool? Many Thanks Rory
  10. Hello I have been having a little dig through the mesh and aided mesh options in Flux to understand what the best meshing strategy is for simulating the interactions between static magnets (mainly disc and spherical permanent magnets). I have done some research into these settings already (e.g. understanding what bubble packing is for face meshing), but I was wondering if anyone here has good knowledge on what settings get the highest level of simulation accuracy (while trying to minimise the number of required nodes and computation time)? Also, if anyone is able to point me in the direction of good literature about optimising meshes for magnetic interactions, that would be appreciated. I do have some specific questions on the options available for mesh and aided mesh options: Relative precision for distance between 2 points is 1e-5 for both geometry and mesh (despite flux recommending that the geometry is superior to the mesh) Is this a good starting value to do comparisons with (and is there any research/literature to support this)? Is there any existing literature or experiments that compare the flux mesher to the MeshGems mesher to compare the differences in simulation accuracy? For uniform vs Dynamic mesh points Is the dynamic mesh point generator iterative? It doesn't seem like it based on it's description, but when I research "Dynamic mesh points", all I find is information on types of "Adaptive mesh refinement" If dynamic mesh points are not iterative, is it only useful for reducing computation time? Can anyone recommend good literature that compares relative node deviation (equal number of nodes on a given line) to absolute (equal spacing between all nodes)? I am assuming the only benefit of mesh relaxation is to save computation time? Can anyone recommend literature on the advantages/disadvantages of using, what flux refers to as, the aided shadowface (which is disabled by default)? Another question I have is: how do meshing requirements for electromagnetic simulations vary from structural ones? Can I use literature for structural FEA meshing and apply that to what I am doing here? If anyone is able to recommend literature that compares the two, that would be appreciated If anyone is able to comment on even one of the many points listed above, to help me understand how to optimise my meshing, I would greatly appreciate it! Many Thanks Rory
  11. Hello Alejandro, Thank you again for the help! I ran the simulation and found that the torque deflection curve was not what I was expecting. I changed the model so that the compressible region contains all the magnets (not just the rotating ones) Original compressible region: Modified Compressible region: I assembled all the volumes within the compressible area (Like you described in your previous reply) I ran the simulation again and got good looking results! However, I noticed these errors: "The region MAGNET_ROTATING_LEFT....." error repeats itself a lot (for each iteration I think) I tried re-assigning the region to volume 7 (Compressible region on the right), but that has not worked I have attached the new version of the project file (I deleted the results as the file was too large) Please can you have a quick look through it (and solve the solution again to see the error messages) to see where this error is coming from? Many Thanks Rory RORY_ROTATING_MAGNETS_V2.FLU.zip
  12. Hello Alejandro, I have tried inverting the field directions of the magnets on one side of the rotation and the torque deflection curve still does not plot Please see attachment for my project folder, please have a look if you can Thanks for your help Rory RORY_ROTATING_MAGNETS_TEST.FLU.zip
  13. Hi Alejandro Thank you, I have managed to set up the magnetic fields and the fixed the rotation of the magnets thanks to your help. Please see below: White arrows are from the two moving magnets Purple arrows are from the static magnets I have plotted a torque deflection curve using the method you described, but I still get this: I have also tried plotting the Torque curves of the regions of the two rotating magnets, that has produced the same curve as above I have orientated the magnetic fields so that the four static magnets always repel the two rotating ones, regardless of its position. So the torques on each magnet should not be cancelling each other out I'm unsure of what I'm doing wrong, are there other ways of plotting this? Many Thanks Rory
  14. Hello I am trying to simulate the pushing force required to deflect a spherical magnet away from a fixed disc magnet. I have already run a simulation of it, please see below: The arrows indicate the magnetic field directions that I have applied to each magnet The direction of deflection is indicated with the red arrow However, during the physical experiment for this, the spherical magnet rotates as it deflects (So its south pole is pointing towards the static disc magnet). At maximum deflection, the spherical magnet deflected 90 degrees upwards (so the arrows on the picture above would be pointing in the positive z direction). My question is: How can I add a rotation or a mechanical set that allows the spherical magnet to rotate about its x-axis centreline while it translates? For my translation, I have done 20 steps of 1mm to get it from 0-20mm deflection So for rotation, I guess I would want to do 20 steps of 4.5 degrees, but I only know how to translate objects about a fixed point, not a moving one Any help with this would be greatly appreciated Many Thanks Rory
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