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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. 

Amar17

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About Amar17

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  1. Time step for small element size in Radioss

    Sir, I tried checking time step with Check elements Panel, but an error popped up:- "HM_CALC_TIMESTEP_func: Division by zero error" Does the F10 panel calculates considering both the elemental and nodal time steps? Also, What care we should take to keep the nodal time step maximum?
  2. Hello everybody, I want to perform an explicit analysis in radioss. I have read that we follow a time step of 1E-06 sec for steel with minimum element size of 5 mm. In my case the element size goes up to 1 mm. I have gone through the book "Crash Analysis with Radioss", according to which we have to look for two formulae to calculate the time step- one is elemental time step and the other is nodal time step. With an approximate sound speed of 5000 m/s through steel, I calculated the time step of 2E-07 sec [i.e., 1 mm / 5000 m per sec]. But I am not able to figure out how to calculate the nodal time step? Would somebody help me out with this? My question is - how much smaller time step would I require to take (for steel) in this case? [Please suggest me an optimum- rough estimate for the element size of 1 mm for steel by taking into consideration the nodal time step also].
  3. 2D to 3D meshing

    Thank you for that sir! But what about connection between the two bodies? Should we merge the nodes at the connection or provide some connection? For the latter case what type of connection you would suggest me for an explicit analysis (in Radioss)?
  4. 2D to 3D meshing

    I have a 2D to 3D connection as shown in the attached image. Please guide me for this.
  5. Element formulation

    This means we can store different element types of a single solid in different component collectors and assign them different formulations. Wouldn't it create any problem? Because, once when I was analyzing an assembly, I stored all the component in a single collector and wasn't able to find any penetration. Please tell me if I need to take care of any such probable concern while defining element formulation for different element types in a single solid?
  6. Element formulation

    I have a component meshed with different elements (Hexa, Penta and tetra). The problem I am facing is while defining the element formulation of the component. How one can define element formulation in such case? The problem is the same for the case of 2D plates when we encounter quad and tri elements in a component. I also searched the answer for this in the book "Practical aspects of FEA" but couldn't find it. Please guide me through the problem.
  7. Hello Everybody, I am trying to mesh a stepped cylinder. In HyperMesh we find the surfaces of cylinder get divided into to halves. In my case, as these halves are connected, I am not able to get an uniform 2D mesh at the cross section. I have tried to toggle the partition lines but couldn't solve the issue. Please tell me, how may I get this resolved. I am attaching the images of my problem
  8. 2D Meshing between the elements

    Thank you Nguyen-Dai! But after doing this way, the elements on the new surface are not connected to the elements from previous surface.
  9. Hello Everybody, I am attaching the illustrative s of the problem I facing. I have a portion of the surface meshed and I want the remaining portion to be meshed. How to achieve this?
  10. Element Quality Check 3D

    @Prakash Pagadala Sir, please tell me what to for 2D to 3D mesh connection in cases as illustrated in aforementioned images.
  11. Query on meshing

    Thank you sir for your reply! But I mean what I wrote. Also I have gone through the book you suggested but I was unable to get what I need to know. I am putting my question once again here - 1) Does the meshing in one portion of a single component affects the results in other portion of the same component? 2) Does the meshing in one component of an assembly affects the results in other components of the same assembly? What do I want is to mesh critical portions with good mesh quality and remaining portions with the mesh having quality only good enough to capture the features of the component. Please give me guidance for the approach I am thinking of.
  12. Solid mapping

    Thank you Q.Nguyen-Dai! It really helped me!
  13. Query on meshing

    Dear all, I have following doubts in meshing: What if I do good meshing in one portion of solid (say critical portion) and poor quality mesh in some other portion, do the results in the good mesh region are affected by the results of poor mesh region. Or do they remain unchanged? If possible, please explain the reason for the answer. What if we couldn't maintain uniform mesh size in non linear analysis?, If I use small elements to capture the geometry and large elements to keep nodes as less as possible then it causes sudden transition between the two. Does it affects the results badly or increases the solving time?
  14. Solid mapping

    Yeah sure, but I would like to know how to do it. I am attaching it herewith. holder.hm
  15. Solid mapping

    Dear all, I have attached an image of my model which seems mappable but I am not able to map it in the HM. Please help me.
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