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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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  1. 2 likes
    Hi Rahul, This is a know issue with HyperWorks 2017 and our devs are working on it. There is a workaround for this. When you create a Frequency response DO NOT select the loadstep. Instead refer to loadstep when creating objective or dconstriant.
  2. 1 like
    set a [lreplace $a 1 1] you can redefine lremove proc like this (to use outside of hyperworks scope): proc ::lremove args { set list [lindex $args 0] set ritems [lrange $args 1 end] #set result [lmap item $list {if {[lsearch -exact $ritems $item]==-1} {set item} else continue}] set result {} foreach item $list { if {[lsearch -exact $ritems $item]==-1} {lappend result $item} } set result }
  3. 1 like
    Hi, The ideal shape for a tetrahedron element is an equilateral tetrahedron. Various quality parameters check how far a given element deviates from the ideal shape. And a similar quality parameter is tetcollapse. Tetcollapse is defined as the distance of a node from the opposite face divided by the area of the face multiplied by 1.24. Ideal Value of tetcollapse for a tetra element is 1.0 , and value greater that 0.1 is acceptable.
  4. 1 like
    Hello, Use the below command inside "xyz" procedure. .mainWindow.mainWindowForRow2.but_Browse3 configure -background red
  5. 1 like
    Hi, Please find the image below which shows Analysis page and Radioss option to run the simulation.
  6. 1 like
    Hi, This seems to be related to part and Instances format. And unfortunately this is not supported now. Hopefully in the next release this format will be supported.
  7. 1 like
    Hi @JamesMech Here are few suggestions from one of our experts: 1) Refine the mesh and make sure you apply the force on entire top face of the gear 2) Atleast 4-5 layers of elements along the thickness of the tooth to capture proper stress 3) If the displacements are huge, try with NLSTAT
  8. 1 like
    Radial symmetry should suffice, you can follow the tutorial here https://altairuniversity.com/conceptual-design-of-a-3-wheeler-motorbike/conceptual-design-of-a-3-wheeler-motorbike-wheel-rim-topology-optimization/ using extrusion manufacturing constraint can help if you need the shape to have the same cross section through and through...
  9. 1 like
    Hi Pohan, While opening HyperCrash select the user profile RADIOSS V14 and export the file. The file will be exported in 14 version. The other option is editing manually. Export the file from HyperCrash 2017 version. Open the *_0000.rad file in Textpad or Notepad and manually change 2017 to 140.
  10. 1 like
    Hi Looks that it can be mapped as a sweep boss. Let' try it tomorrow... I found it! please refer to this mapping.hm (I think you can finish it, base on my mappings)
  11. 1 like
  12. 1 like
    As mentioned above please create tetramesh using 'mesh to current component'.You can delete all 2d mesh in one go(Delete element by config).There is no automatic way to delete 2d mesh.
  13. 1 like
    Hi, In tetramesh panel we have an option 'mesh to current comp',where the tetramesh will be created in the active collector. Choose the required component collector as current and choose this option so that the created tetra elements will be in the active collector. From the mask browser mask all the 3D elements and delete the 2D elements.
  14. 1 like
    Whatever learning at home or at school, it's very good for learning Your part is simple to mesh. So have a look at Hypermesh tutorials and try it. When you have some difficulties, ask here. But the most important thing is try to do firstly.
  15. 1 like
    Hi, From Analysis page, select contactsurfs, select card image as surfseg and select the elements to create a contact surface. Please go through the video attached which shows the same operation. contact_surf.swf
  16. 1 like
    Hi, No, you cannot change the user profile in between. When a user profile is selected, HyperMesh automatically manages loading of templates and FE-input readers for a given solver interface in the current HyperMesh session. You can define contacts in OptiStruct effectively. I'm attaching a tutorial which shows setting up contact between two parts. Please go through the User Guide of OptiStruct which explains more about contacts in detail. OptiStruct uses its own algorithm for optimization. And I also recommend you to go through various tutorials available in Help on optimization. OS - 1392.pdf
  17. 1 like
    Hi, There are several factors we consider for a good meshing which starts from midsurfacing, geometry cleanup, choosing element size, element type, mesh density, quality....etc. I recommend you to go through https://altairuniversity.com/wp-content/uploads/2014/02/meshing.pdf document which gives a good introduction to meshing and good practices to follow in meshing. Also, please download our free ebook, Practical Aspects of Finite Element Simulation (A Study Guide) which will be a good reference for you on Finite Element Analysis where many theoretical aspects are covered with examples.
  18. 1 like
    Hi Ramakiran, Please check the interface for any penetrations. If any penetrations are there please remove the same. The other checks for high contact energy are: • Set recommended parameter for the contact definition. Suggested parameters for Type 7 contact are Istf=4 Igap=2 Fscale_Gap=0.8 INACTI=6 Gap_min= Fric = 0.1 Iform=2 • Set “physical” contact interface gap value. Slightly increase the Gapmin value also. If friction value is provided in the interface, please remove the same, try running and review the contact energy results.
  19. 1 like
    Hi, In SimLab 14.3, this option was moved to File --> preference--> system--> mouse settings
  20. 1 like
    The equation of motion for a static analysis is as below: [K] {X} = {F} ------------------------------------------ (1) [K] --> Global Stiffness Matrix {X} --> Unknown Displacement {F} ---> External Force Applied. For the body to be in static equilibrium, the net force acting at every node must be zero. Therefore, the basic statement of static equilibrium is that the internal forces, I, and the external forces, F, must balance each other: [K] {X} is nothing but internal force 'I' Equation (1) now becomes, ==> I = F or I - F = 0 -----------------------------------(2) In Dynamic Analysis, the imbalance between the external and internal forces results in an acceleration: F - I = M a. F --> External Forces I ---> Internal Force M*a --> Inertial Forces (mass times acceleration) In linear static analysis the stiffness matrix is constant and shall not change/update throughout the analysis. There are many check need to be performed once you have linear static results for well conditioned problems. The equation (1) is decomposed one time to find the unknown displacement. [K] {X} ={F} After decomposition, a singularity may lead to an incorrect solution. In static analysis to obtain {X} (displacements). Using these displacements, One can calculate a “residual” loading vector as follows: [K] {X} -{F} =δ F This residual vector should theoretically be null (equation 2) but may not be null due to numeric roundoff. In Nonlinear static analysis, The stiffness matrix changes in each and every iteration since the stiffness matrix is dependent on the external load. The external load in Nonlinear static analysis is applied in increments and time here has no physical meaning. Time is just a convenient way to apply full load in nonlinear static analysis. In Optistruct the incremental load is controlled by 'NINC' field in the NLPARM card for NLSTAT load steps, this is a fixed load increment method. If you add the PARAM,EXPERTNL,YES to the deck, the time increment method becomes automatic in which case, the increment (load) is increased or cut back based on the convergence rate. NLGEOM loadstep has automatic time step by default. In NLGEOM loadstep the RAMP load curve can be defined using TABLED1 card and then refer this in NLOAD1 card. In nonlinear static analysis, OptiStruct uses the Newton-Raphson method to obtain solutions for nonlinear problems to maintain the residuals close to zero (equation 2) In a nonlinear analysis the solution usually cannot be calculated by solving a single system of equations, as would be done in a linear problem. Instead, the solution is found by applying the specified loads gradually and incrementally working toward the final solution. Therefore, OptiStruct breaks the simulation into a number of load increments (NINC) and finds the approximate equilibrium configuration at the end of each load increment. It is important that you clearly understand the difference between an analysis step (NLSTAT / NLGEOM), a load increment (NINC of NLPARM card), and an iteration (MAXITER of NLPARM card) The load history for a simulation consists of one or more steps. Within a step you will have many no of increments (NINC), within increment there can be many no. of iteration (MAXITER). OptiStruct checks the equilibrium equation ( equation 2) for each and every iteration. If the solution from an iteration is not converged, OptiStruct performs another iteration to try to bring the internal and external forces into balance. An increment is part of a step. An iteration is an attempt at finding an equilibrium solution in an increment when solving with an implicit method. If the model is not in equilibrium at the end of the iteration, OptiStruct tries another iteration. With every iteration the solution OptiStruct obtains should be closer to equilibrium; sometimes OptiStruct may need many iterations to obtain an equilibrium solution. When an equilibrium solution has been obtained, the increment is complete.
  21. 1 like
    RBE2 should be connected to all dependent nodes & with independent node you can connect bar element.See attached video. rigid-bar.mp4
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