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    • Rahul Ponginan

      Please click here for a short but important announcement   03/26/17

      Dear Users Our Commercial and Academic users around the world can use these same forums here as before i.e. the Altair Support Forum , Commercial users from India with solver queries can go to the Solver Forum for India Commercial Users , Academic Users from India and AOC India Participants are requested to go to the Forum for India Academic Users and AOC India Participants , We will be tending to all queries in all the forums promptly as before, thank you for your understanding. 


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Showing most liked content since 02/19/18 in all areas

  1. 3 likes
    Hello Everyone Firstly thanks a lot Livil for all the help. Really grateful for it. Secondly, here is the file which Livil wrote, in case any one needs it in future. merged.tcl
  2. 2 likes
    Hello, You can do this using TCL. First open the command Window Go to View>>Command Window Then type the following code: *createmark elems 1 displayed hm_getaverageelemsize 1 This will give you the average element size. credits @tinh Thankyou
  3. 2 likes
    Hi, For an elasto-plastic material you can use /MAT/LAW2 or /MAT/LAW36. If the user is having a stress-strain curve use /MAT/LAW36. Create the function usinig curve editor (XYPlots>>Curve editor) and in the material card recall this function as shown below. Please note that the stress-strain curve should have post yield values. Also,the first point of yield stress functions (plastic strain vs stress) should have a plastic strain value of zero. As an example, If the yield value is 90, the curve starts with X Y 0 90 For rigid bodies always use /MAT/LAW1. /MAT/LAW13 is an obsolete card now. As in Dyna you can create a self/global contact in RADIOSS using the Type 7 contact. Select the master and slave as the same and a self contact between them will be established.
  4. 2 likes
    Hi, It's simple: *displaynone *createmark elems 1 "equal to value" propertyidflag 1 *findmark elems 1 0 1 elems 0 2
  5. 2 likes
    Thanks all ! What I want has been achieved by creating the result of { Z1(or Z2) - Mid } layer's von mises stress in "derived results"
  6. 2 likes
    Hi, I have worked in FOAM Material using LAW 70 in one of my project. I tried validating LAW 70 for different scenarios. Attaching some sample validation case for reference. Hope it may help you. Thanks. Comp_20mm_0000.rad penetration_1DOF_0000.rad E_1100_0000.rad
  7. 1 like
    Yes, sliding contact can be used for open and closed contact (NO gap) Try with PARAM>>EXPLRTNL>>CNTSTB and check if this helps?
  8. 1 like
    @dracu777 That means if you applied the displacement at the node for dof1 in type SPCD. You need use the SPC to constraint the same node for dof1.
  9. 1 like
    Hi Pohan, You don't need startnotehistorystate and end endnotehistorystate. All you have to do is: *createmark components 1 "RW_left" "RW_right" "Compresseur" *deletemark components 1
  10. 1 like
    It is not a problem with me. I usually delete command.cmf before I focus on a certain command. the recorder is actually unnecessary if i want to track it, I will set a tracer
  11. 1 like
    please constraint all its nodes by rbe2 and rerun
  12. 1 like
    Hi, script like this proc p_ParseD3hsp {FilePath} { if {[file exists $FilePath]} { if {[catch { set fpt [open $FilePath] set buffer [read -nonewline $fpt] close $fpt }]} { return -code error $::errorInfo } set LineList [split $buffer \n] array set PenValue {} set MismatchedModel 0 foreach Line $LineList { set Line [string trim $Line] switch -glob -- $Line { "penetrating node # *=*" { set NodeId [string trim [string range $Line 28 end]] if {![hm_entityinfo exist nodes $NodeId]} { set MismatchedModel 1 break } } "penetration *=*" { set PenValue($NodeId) [string trim [string range $Line 28 end]] catch { *tagcreate nodes $NodeId [format %.2f $PenValue($NodeId)] $NodeId 2 } } } } if {$MismatchedModel} { return -code error "The d3hsp mismatched with opening model" } #return [array get PenValue] } else { return -code error "File not existing '$FilePath'" } }
  13. 1 like
    Hello, Try to export your model as h3d including FE and geometry (see picture). In Hyperview you can import it as model. The geometry is represented by STL triangle elements, i think. If you need it separately, move or copy the geometry into extra components. Best Regards, Mario
  14. 1 like
    Tinh, it's working, it was a very stupid mistake. I opened the .h3d file and set the animation mode to "set transient animation mode" and it's working. Thank you so much. - Kaushely
  15. 1 like
    You can export these parameters to the *.out file. Presently this option can only be enabled in EDITFEKO under the CS card. Basically after setting the up your model and meshing it in CADFEKO, from there, run EDITFEKO. Find the CS card(s), click on them and hit F1 to edit, and check the box "Export cable parameters to *.out file", save and run FEKO.
  16. 1 like
    Hi, enter reference guide of hyperwork desktop >>Programming with tcl/tk commands >>tcl/tk commands >>hyperworks desktop >>hypergraph 2d >>pltlBuildPlotsCtrl Class there is an example using method "SelectDataFile" to load file for hypergraph
  17. 1 like
    Hi, which option would you like? I see thickness option is "component thickness" which is same as in v14 v2017 can check it base on contact so I think it's better It just hides the original panel. If you still want to use it, try enter commands (in menu View>Command Window): hm_setpanelproc hm_resetmenu hm_pushpanel penetration
  18. 1 like
    ooh, I should have mentioned that I also changed the MORIENT in the contact group to NORM and in PCONT, I activated STFEXP. It was blank before. That might have been the reason for the contact error. Not sure though because I am new to this.
  19. 1 like
    Hi, Can you share the loadstep details? Instead of MATHE use MATS1 with type NLELAST if you are using NLGEOM
  20. 1 like
    Hi tinh, thanks for your answer but finally I could do the script. Anyway, what I had was this (bolt made with several 1d elements): And what I wanted was this (a tag with a ID for the bolt, i.e.5003) : But as I said before I could develop de script. You can delete this topic if you want considering it doesn't contribute to the forum. Many thanks.
  21. 1 like
    Hi @LKZ Makes sense. I will check with experts if there is a better to use RBODY in OptiStruct.
  22. 1 like
    Hi sure, hm_getclosestnode is not working with local coordinate, you have to provide global coordinate maybe, there is some commands to calculate global coordinate, please search them below I will create a node at that position, and retrieve its global coordinate to provide to hm_getclosestnode *createnode 0 0 25 658001 ; #create a node at the coordinate set NodeId [hm_latestentityid nodes] set gx [hm_getentityvalue nodes $NodeId globalx 0] set gy [hm_getentityvalue nodes $NodeId globaly 0] set gz [hm_getentityvalue nodes $NodeId globalz 0] *createmark nodes 1 -1 *nodemarkcleartempmark puts [hm_getclosestnode $gx $gy $gz]
  23. 1 like
    Hi Abhi, The error is not from OptiStuct or not from a static analysis using OptiStruct.
  24. 1 like
    Please refer attached video. Deformed_with_fem_format.mp4
  25. 1 like
    Hi Tinh, it worked....but still getting some gap... see attachment... any workaround. regards, PD
  26. 1 like
    Hi Novak, Are you able to get the desired result from the file? If you're getting what you want you will have to return lst_dispInfo from GetNodalContourValue and set sigma values directly in the below loop like this: foreach n_id $::curSel { set sigma_1 [::hw::post::custom::GetNodalContourValue $n_id "YourResultType" "YourResul/direction"]; #should be matching the file. set sigma_2 [::hw::post::custom::GetNodalContourValue $n_id "Displacement" "Y"]; #should be matching the file. set sigma_2 [::hw::post::custom::GetNodalContourValue $n_id "Displacement" "Z"]; #should be matching the file. ShowCurves $sigma_1 $sigma_2 $sigma_3 #Stress values } If you're authorized to share files, please share result and developed code in the below link. I will give it a try. https://ftin.india.altair.com:8443/filedrop/~QUK1Ji
  27. 1 like
    Unless the structure is completely closed (waveguide or other non-radiating structure), it is difficult to predict what solution method would be the most efficient. You model does have a very thin substrate and that would lean towards FEM (usually). Since you have a radiating structure, you need to add a reasonably sized air box on the front of the structure (where the patches are). I would also use 1st order FEM, since you want to mesh fine. I hope some of these suggestion help.
  28. 1 like
    CD is just a text, dataname of it is outputsystemid
  29. 1 like
  30. 1 like
    Try making a cbush at dependent node and give a high stiffness to pbush
  31. 1 like
    The reason for the error is that lossy metals (copper) is not supported on the FEM / MoM boundary. You need to either make the outer metal PEC or add an FEM air region around the metal so that the FEM / MoM boundary is the "air" region that you add. However, looking at your model, I think the problem is rather the fact that the patches have losses and you will have to add an air region in front of the patches if you want to use FEM. Have you tried using MoM for this model? Is there a particular reason why you want to use FEM? Regarding the meshing, the only thing I can think of is that you can try to create a "unit cell" of the patches and then mesh it. Once you have the unit cell, you can duplicate the mesh for the unit cell. This makes editing the model quite a bit more complex, but it is possible. If I were to do that, I would use scripting. I don't have any other suggestions. We are working on features that would (or could) make meshing these repeating structures easier in the future (but it is still early and in a concept phase). Even with the meshing as you have it now, I'm not convinced the mesh is fine enough for accurate results. I would definitely do a mesh convergence study and also try a few solution methods and settings.
  32. 1 like
  33. 1 like
    Hi Agassi, in the script exchange databases there's a tcl script (No 41044) which does almost what you desire: It creates a pic (of the page) with a factor in the resolution. So you can export pics at higher resolution, but they still depend on your windows size. i.e. in my case the standard pic export will lead to a 1376*640 pic. With this script the pics a x4 quality -> 5528*2600. Does that help? :-) CAE-Guru
  34. 1 like
    The turbulence models all work for either steady or transient flows. You'll need to determine which model to use for your particular application, but it will not depend on whether it's steady or transient. (However, DES/LES would apply only to transient flows.)
  35. 1 like
    By default, AcuSolve looks at both Residual Ratio (a measure of how well the overall solution matches the equations) and Solution Ratio (a measure of how much the overall solution is changing from time step to time step). By default the Solution Ratio can be an order of magnitude larger than the Residual Ratio. If you look at the plots for Solution Ratio, you'll probably have one or more variables that is too high. For Solution Ratio, with convergence tolerance at 0.001, eddy-viscosity would need to be below 0.1, pressure and velocity below 0.01. High values of solution ratio indicate the solution is changing a lot from time step to time step - thus indicating it's probably not really a steady flow.
  36. 1 like
    Hi Ganesh, For hyper elastic you can try with /MAT/LAW69 or /MAT/LAW82. And for failure, you can try with /FAIL/TENSSTRAIN failure model.
  37. 1 like
    Hi Pratik, Explicit scheme is a function of time and the explicit algorithm works in time step increments.Time step is the time required for a shock wave (governed by the speed of sound) to propagate across the smallest distance of the element. A run is a single model simulation and it starts at time zero and continues till the user defined endpoint is reached. From the above relation, it is clear that both material modulus and density control the speed of sound. The solution time step is inversely proportional to the speed of sound. So, if the material is stiffer (higher modulus of elasticity), the speed of sound increases resulting in a lower solution time step. Thus, to keep a stable solution, the shock wave through a medium must not pass across more than one element per time step. This implies that the length of the element is the modeling parameter that affects the overall solution time. Usually explicit analysis lasts only for a certain milliseconds, like crash, impact, drop...etc. Basically the user should get enough experienced in explicit analysis so that before running the analysis user can estimate a rough run time. Based on the energy plots once the system is stable we will terminate the run and thus a run time is calculated. In your simulation in order to achieve such a high deflection the run time was estimated for 4sec and hence I asked you to run with OptiStruct as your case is not an explicit one. Regarding the number of animation files, we always recommend to write 30-40 animation files which will give a smooth result.
  38. 1 like
    Well, maybe this how it was programmed at the beginning. Proposed, In next version shuffling with MAXSUCC constraint will support all angles.
  39. 1 like
    Hello, Do it as tinh has proposed. Be sure to load your files with Result-Math template "Advanced". Then call the Expression Builder (Derived Results) and create a Tensor for bending. See attached picture. Best Regards, Mario
  40. 1 like
  41. 1 like
    OptiStruct can only accept one SPC and one LOAD component in a subcase, by default. In other words, multiple load collectors with e.g. different SPC's can't be referenced in the load step panel. There are two ways to apply multiple constraints and loads in a subcase. 1. Put multiple loads in one load collector, and include that one load collector in the subcase. The same method can be used in the case of multiple constraints. 2. Create load collectors for each and every load and constraint set. When you want to apply multiple loads in a subcase, a new load collector needs to be created with the LOAD card (=CardImage=Load). Then, individual load collectors can be combined using the LOAD card. The LOAD card also enables you to associate an independent weighting factor to an individual load collector. In the case of applying multiple constraints, create a new load collector with the SPCADD card (=CardImage), and follow the same procedure as in the multiple load case. Once the combined load collectors are created, they can be applied in a subcase.
  42. 1 like
    Attached PPT contains the tests to be done to verify the Creo configuration in SimLab. SimLab_Creo_Configuration_Test.pptx
  43. 1 like
    Hello Sir, I am Sanjeev Kumar, currently pursuing my Mechanical Engineering from Pune University, India. Sir, we are working on a project based on Biomimetics of a butterfly. In this project, we have to analyze the motion of the butterfly while in motion. We have to perform CFD and crash analysis of the butterfly in Altair/LS Dyna as the one shown in the attached GIF.But we don't know this is possible in HyperWorks or not if not can we take help of Ls Dyna.because the major problem we are facing is how to apply motion to the wings of a butterfly and how to apply moving mesh to simulate this. If it is possible then please help me that how can we do this we are unable to find tutorials on the internet. Sir it would be great if you will help. Thanking you in anticipation With warm regards sanjeev kumar sanjeev110795@gmail.com 7030305737
  44. 1 like
    Hi, Please find the video attached which shows Airbag Simulation. Also, please go through https://www.youtube.com/watch?v=kCSRFss6GDE&list=PLQ7KUGFuVz4u5y3SvIEIU07427-gATaG6&index=5 which is a webinar showing creating monitored volume in RADIOSS. Hope this helps. Airbag_simulation_setup_.mp4
  45. 1 like
    Hi Amar, The nodal time step equation is : sqrt (2m/k), where m is nodal mass and k is equivalent nodal stiffness. A scale factor will be also used to calculate the time step. Please go through https://altairuniversity.com/learning-library/considerations-about-time-step/ which is a webinar showing time step calculation in RADIOSS. RADIOSS will calculate nodal and elemental time steps of the model and will choose the highest of these to run. From Check Elems (F10) panel it is possible to determine the approximate minimum time step for explicit solvers based on element dimensions.
  46. 1 like
    Hi, The recommended value for energy equation is as follows: (Hourglass energy +contact energy)/TE this should be less than 15 % In your case this i very high as contact energy is almost same as TE and even higher than it. It seems there are penetrations in the model. Check this in hypercrash. Also check whether any incompatible boundary conditions are there in model.
  47. 1 like
    Submitted by linklessa on Mon, 12/14/2009 - 17:27 Hi. I'm new in this area and need to do a V/f control for a inductoin machine. I didn't understand which block I have to use. There are three that I guess can be used: Space Vector Generator (Magnitude, Frequency); Space Vector Generator (PWM); V/Hz Profile Generator; But I didnt'n understand very well how this blocks works... Somebody can help me? I need to do a simple V/f control (I guess is simple). There are some example that I can use? I see some topics abaout it, but I think that is not the same for me... Thanks
  48. 1 like
    Submitted by pete on Tue, 02/09/2010 - 20:05. Hi Vijay, You don't say what you want to do with your sin. Usually you are modulating a PWM our something similar. Anyway, for the the F28335, which supports floating point, you can simply use a Blocks > Signal Producer > sawtooth block, set the gain to "2*pi" and frequency to desired sin freq, and connect it to a Blocks > trancendental > sin block. Then connect the sin to ePWM or serial write or whatever you want: If you want to use fixed point, then use Diagrams > Tools > Fixed-point > Ramp32 and connect it to Blocks > Fixed-point > sin
  49. 1 like
    Hi Rahul. Thanks for this useful information. Now I could combine multiple loads(Force, Pressure, Enforced displacement, gravity) to do analysis with Optistruct. However, do you know how to create "Subcom" in HM/OS (combines loads but still allow accessbile each load case). Thank you very much.
  50. 1 like
    Thank you for the kind offer, but I had some help from the helpdesk and using Tool>edges>components>equivalence sorted out all the 312 Errors (it eliminated the free ends on my 1-d elements?):d/