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  1. 2 likes
    Based on my quick look at the database, you do not have the interface surface attached to the Rotor volume - only that for the Fixed/main volume. Right-click 'Air-rotor' under Volumes and select Mesh Op. > Find Missing Surfaces. This will generate the other set of surfaces, attached to the Rotor Volume. It appears you already have two sets of nodes there, but the surface definition was missing. This new surface set should have the same treatment as 'interface' > deactivate Simple BC, and activate Interface Surface with 0 for gap and gap_factor. If you know or can estimate the angular velocity, it's simpler to use rotation mesh motion rather than rigid body. It's difficult to estimate the resistance to rotation due to the gearbox, etc, so the angular velocity / rotation from Rigid Body motion is probably going to be higher than the actual would be.
  2. 2 likes
    Hi Laura, You can merge the bodies in MV keeping only the necessary components to represent your system. For instance, parts represented on the CAD like bolts, bearings, welds, etc do not need to be represented in your simulation. Therefore it is either recommended to group it in one single body or delete them. Best regards, Felipe.
  3. 1 like
    Hi Geraldo, FASTFR : This option is used to activate "The faster modal solution method" for modal frequency response analysis ! FFRS : The second means FAST Frequency Response Solver, used if you want to activate the external FASTFRS solver. This solver works well for a large modal frequency response. (You have to install it in advance). FFRSNCPU : used with FFRS. It's useful if you want to define the number of CPUs to be used by the external solver "FAST Frequency Response Solver". FFRSLFREQ : It's a threshold (cut-off frequency) used to partition your system into low freq and high freq. Cheers,
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    Hi I have an example here I will give the code later because it is in my pc https://forum.altair.com/topic/16835-update-hypermesh-extensions/?tab=comments#comment-30266
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    You could make use of LDM field in the load map to change the stress units.
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    LS-DYNA solver, as Optistruct also,... are unitless. User should warranty unit consistent. So to fit the unit system of HyperLife, maybe you need do all changes for LS-DYNA input.
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    Currently below solvers supported: OptiStruct, Nastran, Abaqus & Ansys Example if the converted h3d from d3plot, result contour is Von Mises, only von mises results will be present in the exported h3d, for all the time increments. ( there are chances the result type can also be renamed,and also miss the layer information in case of shells)So when this h3d is loaded in HyperLife, the necessary query information for the stress might not be available for the required calculation.
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    PEC is treated as infinite conductivity. The "gaps" inside the wire model is of the order of the wavelength so I would not say these models are equivalent.
  10. 1 like
    This model is not suitable for UTD. UTD is for electrically very very large surfaces. There are small details in the model not suitable for UTD assumptions. You would have to use either MoM or MLFMM. (With multiple incident angles, the MoM might actually be the fastest, if you have enough memory for an in-core solution) PO would be faster, but again there are small geometrical details and possible resonances there would not always be modeled by the PO.
  11. 1 like
    Rotate the green so its nodes become concide to the blue one.
  12. 1 like
    When you use tetramesh panel, switch "mesh to current comp" to "create per-volume comps" HM will seperate volumes for you.
  13. 1 like
    Hello, The answer to your question is explained in another post. Here is the link:
  14. 1 like
    Hi, the first run ended with the -0.7% energy error and the second run starts from 0% energy error. The energy error is reset to zero on restart so there is actually no energy increase. To restart from the previous energy balance a *.ctl file should be created with /STOP defined (similar to the checkpoint CHKPT command in Radioss Solver Run Manager). The /AMS in the starter is used to declare components on which AMS is applied and is defined only once. /KEREL is applied in the engine file.
  15. 1 like
    This was implemented in 14.0.Please refer attached material for Rbody. Rigid_bodies.zip
  16. 1 like
    Hi @lostarmour, Use the attached model: 08262019_Feko_two_blades_alt_2018.cfx What you probably didn't do is coarsening the mesh.
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    Please refer to attached fem deck. LM.fem
  18. 1 like
    For rigid element no need to define property. For constant mass component create CG and connect Specimen/Constant mass component with RBE2 to the CG of constant mass. You could use CONM2 for concentrated mass.
  19. 1 like
    The image does represent Q Criterion, colored by something like velocity magnitude or pressure. You should create in isosurface of Q Criterion, then select a value for Q Criterion that gives you the 'look' you want. In the function calculator, you would put the velocity function - the vector - inside the parenthesis.
  20. 1 like
    Hi, the shell thickness is supposed to be this thin (0.0004m). And yes, the unit system is N, m, s. I am aware of the warning (thanks for pointing it out anyways). As it does not effect similar analysis I have run with same shell thickness, I don't suppose this will be the source of the oscillations. Cheers
  21. 1 like
    Hi, hopefully, someone from Altair support will look into the issue. the unit system is N, m, s and the plate dimensions are 0.05x0.26. In the description above you mentioned the shell thickness is T=0.4 (meters?) but in the model the shell thickness is 0.0004 (0.4mm) resulting in the warning message reported in the out file: While I'm not sure if this might be causing unexpected oscillations, it should at least be checked. Unfortunately, I have no experience with comparable models to give useful tips.
  22. 1 like
    Please refer Thermal Ebook. https://altairuniversity.com/free-ebook-thermal-analysis-with-optistruct/
  23. 1 like
    You need to do "equivalence" of nodes.
  24. 1 like
    Hi, you can try to add torque based on BISTOP function to limit joint motion. Please refer to the attached document (from Hyperworks for MBD 13). HyperWorks_for_MBD_v13.pdf
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    I would suggest you to use the same parameter file with 2019.0 version where new and powerful mesh flow algorithm is used.
  26. 1 like
    "Collision Detection" is a feature that's only available in post-processing. It allows you to visualize penetrations between different bodies in the mode, AFTER your simulation is completed. When you need to stop (or change) the model as a result of some condition in the model during run time, we use an entity called Sensors. I would encourage you to read up on Sensors in our help, as they are quite powerful, but there are a few things to learn. A simple way to implement a sensor in your case would be for the sensor to monitor the displacement between two bodies (which you would define via an expression). When the displacement reaches some threshold value, you tell the sensor to halt the simulation. Another possible way (I haven't personally tried this), would be to monitor the contact forces between two bodies, assuming you are using 3D contacts in the model. When the contact force is generated, use that to trigger the sensor.
  27. 1 like
    This's local stress due to RBE2. If it's too high for you, you need add a plate below the tube.
  28. 1 like
    Hi, The eigenvalue solver only works with SMP (-nt) parallelization and not SPMD (-np). However, even when I try to run the model with -nt it does not run. Using flexible body in a simulation has many limitations and does not work with many new Radioss options. I would recommend not using this method. For longer simulation times you can use regular mass scaling (/DT/NODA/CST) or Advanced Mass scaling /DT/AMS to increase the time step and reduce the simulation time. Thanks, Andy
  29. 1 like
    Hi Dhairyasheel, 1. first create a font with the properties and then assign it to the label you create font create myFont -family cambria -size 14 ttk::label .test.frame1.label1 -text "Hello" -font myFont -width 15 2. all entry boxes have a variable set using -textvariable which should be a namespace variable, this can be set dynamically and will be reflected accordingly. hwtk::entry frame_1.ent_1 -textvariable ::mynamespace::entry1variable 3. use -command followed by the function while creating the button: hwtk::button frame_1.button_1 -text "test" -command {::test::Myprocedure}
  30. 1 like
    Hi, *createmark elems 1 "on plane" "x y z i j k tol plane touching" "
  31. 1 like
    Hi, to extract the contact loads from Radioss simulation and use them for Optistruct optimization follow the procedure from the attached reference (page 32): Identify the time of contact force peaks by requesting /TH/INTER contact interface output block and postprocessing in Hypergraph. Define /ANIM/VECT/CONT output request and query the contact forces on nodes of interest at the time of contact force peaks in Hyperview. Export the data in csv file format. Import the contact forces in Optistruct by Analysis>forces>linear interploation>file As discussed before, the element size in the region of interest should be 5-10mm. Using such refined mesh on the structure as big as the railcar will be computationally expensive in terms of CPU. If we only want to extract contact forces (using the above procedure) and assuming the walls of railcar are not deforming we can put a rigid body on it so the timestep is not penalized by the small mesh size anymore and only SPH and contact interface will dictate the timestep. Optimization could then be performed in Optistruct using refined mesh with finer contact force resolution- this could be computationally expensive in terms of RAM. I am not at my Hyperworkstation to check your model, but I can offer the following observations based on shared input decks: Stress constraint is not recommended in the design concept stage: topology, topography and free-size optimization. The stress constraint definition in a topology optimization is a global constraint and does not target local stress concentrations. These areas can be addressed subsequently through size, shape, and free shape optimization or a combination thereof. Artificial stress concentrations are filtered out during topology optimization with stress constraints. These include regions around rigid connections, concentrations due to hard geometric features such as corners, etc. Stress constraints for a partial domain of the structure are not allowed because they often create an ill-posed optimization problem since the elimination of the partial domain would remove all stress constraints. Consequently, global stress constraint applies to the entire model when active, including both design and non-design regions. Stress constraints may not work well in a model where there is a large differential in response values between design and non-design spaces. In these cases, it is recommended to modify the problem formulation to say, compliance-based for example. It is not recommended to use the global stress constraint along with a mass/volume constraint. The constrained mass/volume may not allow the stress constraint to be satisfied. Unless mesh is stress converged then the stress constraint should not be relied upon. Instead of minimize weight subject to displacement and stress constraints try to minimize compliance subject to volume fraction or mass constraint.
  32. 1 like
    Hi Sourav, Highly appriciate your prompt and detail answer. Thanks!
  33. 1 like
    Hey Hoang , 1. Vacuum pressure is still not supported in the software. 2. You cannot use gravity-tilt process to simulate Centrifugal Casting ( Centrifugal is not supported yet) 3. yes we have planned in 2020 (solver is ready, we need to add in interface), Hopefully by next year we all shall be able to use these commands. With Kind Regards, Sourav Das | HyperWorks Specialist-FEA| Global EDU | Academic Program | sourav.das@altair.com | www.altairhyperworks.com Altair | Innovation Intelligence® Secure file dropbox https://ftam1.altair.com/filedrop/sourav.das@altair.com
  34. 1 like
    Hi, glad to help. In the explicit quasistatic analysis it is recommended: The loading should be gradually ramped up from zero over a reasonable period (at least 0.3 s). Instantaneous loading (non-zero loading at time zero) causes propagation of a stress wave through the model similar to impact load. The kinetic energy should be bellow 5% internal strain energy throughout the simulation to ensure a quasistatic process without inertial effects. Vibrations should be damped using for instance /DAMP Rayleigh damping. The implicit quasistatic analysis with instantaneous loading has convergence difficulties as the equilibrium solution at initial load is far from the initial position. As a workaround try: create two engine files with the first engine ending after the preload is applied using the ramping function and the second simulation starts in the equilibrium condition perform pretension analysis and export deformed shape and stress fields using STATE file. Then initialize the stresses and deformed position in the original solver deck. However, this approach is not tested as I am away from my Hyperworkstation. Implicit and explicit solutions can be compared only if the explicit solution satisfies above recommendations regarding slower loading and damping- both will increase explicit solution CPU time. The implicit solution could be further optimized for better convergence. Note also that Radioss implicit is only meant to complement explicit (capability to switch during simulation)- otherwise use NLSTAT non-linear quasi-static analysis in Optistruct.
  35. 1 like
    Sorry, I don't know CADFEKO. But I can confirm you that your STL is valid & readable
  36. 1 like
    Dear Nasim, No problem. In fact, KTex WovenProperty only calculates a homogenized macroscopic material card for a ply. There is no mesh. The only thing you can import is the material card. It is comparable to HyperLaminate. KTex WovenProperty exports the results in different formats. The .fem file is for OptiStruct and the .rad file is for RADIOSS. Best regards, Edouard
  37. 1 like
    Dear Cna, The first output I would think of, would be to project the elemental frame of your fibers onto the macroscopic elements of your radome. I am not sure this output is available directly in HyperView, but I am sure you can create a contour based on the elements coordinates. You should then be able to compare the angles of the weft elements to the warp ones. And this comparison could be a angle change, as you know the initial angle of your fabric. Does this seems to answer your question? Best regards, Edouard
  38. 1 like
    Hi, to minimize compliance use minimize internal strain energy response (RTYPE=8). Unfortunately, not all responses are available for Radioss optimization. When the desired response is not directly available from Radioss, it may be calculated using /DRESP2. Or the model could be converted to Optistruct and run explicit dynamic analysis (Radioss simulation in the background). _DRESP1.pdf _DRESP2.pdf
  39. 1 like
    Hyperworks desktop: .mainFrame.bottom.leftfrm.label cget -text Hypermesh: .mainFrame.bottom.message_label cget -text
  40. 1 like
    Hi Eliz 1. The idea is to add as little as possible "air" tetrahedra to the model while still "absorbing" the fine elements inside the added tetrahedra. It will always depend on the model. With the original model and spacing required I would create two identical elements each with it's own "air" dielectric. For example: 2. FEM/MoM and FEM/MLFMM is essentially full wave solutions, so all coupling effects are taken into account. In the v2 and v3 models you attached I don't see the feed lines you had in the original models. I cannot comment on the design/thinking behind the antenna. The modal port is not suitable for "microstrip" type feeds. Attached an example from the original model where I added one line port only. No air has been added. Viv_2el_TX_patt_v6_lineport.cfx
  41. 1 like
    Hi, given the impacting object's high kinetic energy (KE = 71940 J or 430x the energy of a .22 rifle bullet) fragmentation on impact is expected. However, From Radioss help: As a workaround, define FAIL/TENSSTRAIN card to get a more realistic fracture behavior. Collision_edit_0000.rad
  42. 1 like
    Hi @bouvy, Does running a simulation from CADFEKO work?
  43. 1 like
    @SergioV: You have 445 elements with aspect ratio > 20! So please make correction of your 2D mesh before filling 3D.
  44. 1 like
    hi sergiov, free edges are there in this region.Connect these nodes and do tet modeling.
  45. 1 like
    DAREA is for dynamic loads whereas FORCE1 and FORCE 2 is for static loads. Combinations of dynamic loads (DAREA) with static loads (FORCE, FORCE1, FORCE2, MOMENT, MOMENT1, MOMENT2, PLOAD, PLOAD1, PLOAD2, PLOAD4, and RLOAD), is supported. Please refer free ebook on Dynamic analysis using OptiStruct using below link. https://altairuniversity.com/free-ebook-learn-dynamic-analysis-with-altair-optistruct/
  46. 1 like
    Yes, u can model laminate material as blank via single action, double action, triple action or any other tool setup u want. to make ur blank laminate use layered option in blank configuration.
  47. 1 like
    i just tried to do Analysis with Radioss and it showed me waring 312... so what is it about ? please someone explain it..thank you
  48. 1 like
    Free eBook: Design the Inspire Way – A Practical Introduction to solidThinking Inspire click on the title here This book is a very light-weight introduction into the exciting world of the “Simulation Driven Design Process”. It is meant to give pupils, undergraduate students and maybe even designers new to Computer Aided Engineering CAE a “taste”, a first idea on how simulation, especially conceptual design (simulation) works. The tool of choice used in this book is solidThinking Inspire®. Inspire enables design engineers, product designers, and architects unfamiliar with numeric simulation, to make optimal use of the material by placing it only where needed to meet structural requirements. Become Inspired ...
  49. 1 like
    Alex, It has been a while since you asked that question. I don't know if you still need help. If you do, please check Analysis -> Preserve nodes see if there are any preserve nodes in your model. HM would automatically delete those once you transfer any preserve nodes to normal nodes.
  50. 1 like
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