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simulation explicite

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Everything posted by simulation explicite

  1. Hi, When two bodies come in contact, the contact area is not known in advance. Thus, contact problems are highly non-linear due to the unknown surface boundary conditions. In the meantime, the presence of friction adds another nonlinearity to the problem since it is irreversible and discontinuous. Moreover based on the friction law selected the solver will find the 'stick and slip' of master and slave in each cycle. Check online on contact algorithms to learn more about contact formulations in FEA softwares. Best regards, .
  2. Hi, You can simulate crack propagation with Law36 using extended finite element method (XFEM) in which you can select the enrichment zones and can provide the failure criteria. Please check the Help on /FAIL/XFEM. Another option is assigning damage property cards where user should have all the damage parameters (D1,D2,D3). These need to be experimentally found, and there is nothing to do with stress strain curve for these. Many open web resources are available for finding these parameters. Please check for the same. Another easy method is to assign failure plastic strain directly in material card (EPS_Max). Elements reaching this failure strain value will be deleted from the model. Best Regards, .
  3. Hi, For mass scaling I would recommend you to go ahead with AMS, as this is a quasi static case. Make sure you properly select a time step for enforcing. Finally ensure from T01 file that you have a very low/negligible KE for a quasi static analysis. Best Regards, .
  4. Hi, As far as I remember the element deletion will happen only for conventional shell elements. For other element types the deviatoric stress will be set to 0 once the element reaches the failure criteria. Best Regards, .
  5. Hi, It is time consuming when you go for each part. Unfortunately there is no other option available in HM or HC. The only way is to create a script for this. With customization you can do these steps very easily. Best Regards, .
  6. Hi, Adding friction values to a contact makes the case more non linear and that's why you are getting high contact energy. In such cases you can safely discard this high contact energy. If the contact energy is due to penetrations/intersections/contact definitions...etc then you will have to pay attention and need to reduce. Best Regards, .
  7. Hi, Check this RADIOSS video learning series: https://m.youtube.com/watch?v=FjErJVigVJU&index=2&list=PL1u26y75SCrA_BOCLaSewVCNY7xRvCTnA&t=14s Creating Type 11 contact and the various contact parameters are covered here. Also they have released a free RADIOSS ebook which is very useful for beginners. Many FAQs, tutorials, theoretical background....etc are well covered in that.
  8. Hi, If I guess right lead behaves as a plastic material which is easily deformable. In such a case I don't think using Law 1 is good. You may to try with Law 2 or 36.
  9. Hi, I think one tutorial is available in Help showing sequential loading in RADIOSS. Check for tutorial RD-3599 (Gasket with HyperMesh) for better understanding on defining the curve for a sequential loading case.
  10. Hi, In RADIOSS solver manager remove any commands from the run command field, and run the analysis.
  11. I think he is trying for a symmetric contact. For all components he has modeled a symmetric contact?.
  12. Hi, For tetra elements Isolid will not work. You can use Itetra option instead in the property card. Create output block for all components and plot the hourglass energy graph for all components and thereby find the component responsible for high HG energy.
  13. Hi, For a clamped model like this it will always tend to break from the fixed end as all the dof is arrested here. And that's why you're getting high stresses at fixed end.
  14. Hi, A function is missing in your model file which is required for running. It seems from the loads the function is missing. Do you have concentrated load or any imposed loads in your model?. If so, those loads require a function wrt time and the load will be ramped accordingly on to the model.
  15. Hi, The error shows that the master surface is empty. Please update the master and slave and click on review so that the slave will be displayed in red colour and master in blue and by this we can reconfirm that the master and slave is updated properly in the interface. Are you trying to define it for solid components?. If so, create a contact surface for the same and recall the same in the master of interface.
  16. Hi, Assign the number of cores (-nt) in RADIOSS solver run manager and review whether it helps
  17. Hello, Isolid is to choose hex element formulation, whereas I_tetra option is used to select the tetra element formulation. Isolid will not be considered if you choose for Tet elements
  18. Hi, For modelling glass failure I would recommend you to create a failure card for this, which will simulate a realistic fracture modelling. You can choose /FAIL/FLD (forming limit diagram) failure card for the same. User should have the FLD curve from experimental testing. Check this tutorial at https://altairuniversity.com/conceptual-design-of-a-3-wheeler-motorbike/conceptual-design-of-a-3-wheeler-motorbike-stone-impact-simulation/ which shows the methodology for model setup.
  19. Hi, Free dummy models are not available. But one tutorial is available in Help (HyperCrash tutorial, RD 3150 seat crash) where I think a 50 percentile rigid dummy is used and this model is available, which you can check in your installation directory.
  20. Hi, Try these workarounds: Hourglass seems to very high in the model. For solid elements use Isolid-24 and if any shell elements are there use ishell-24 and N-5. For the contact keep Istf to 4, so that minimum of master and slave will be calculated. Also give a minimum stiffness (Stmin-1000N/m). Plot the global contact energy also. Ramp the load in 300 milliseconds so that the solution will be stable. Once these changes are done, run the simulation and plot the hourglass energy for each part so that we can see which part is contributing more. And finally make sure correct material type and parameters are used. Which material is used for this?.
  21. Hi, You have to create and put RBODY in the output block, so to see the insertion force. Plot the force on this RBODY in the required direction using T01 file in HyperGraph for the insertion force. Similarly retention force is the one which needs to be applied in the separation direction to disassemble it, which is contact normal force.
  22. Hello, From Analysis page choose output blocks and select elems from the selection menu and select the rigid body elements, click create and click edit. Keep NUM_VARIABLES as 1 and under Var option type DEF, so that all default outputs will be extracted for the rigid body. Check /TH/RBODY in Help for the outputs available.
  23. You have to create and put RBODY (for pressing dolly) in the output block, so to see the insertion force you can plot the force on this RBODY in a particular direction using T01 file in HyperGraph. In a similar way for Retention force you have to see the Interface(Contact) force in HyperGraph. Plot Normal Force (NF). I don't think this is possible in RADIOSS.
  24. Hi, For the cross sections created, define output blocks for the same and with which you can plot the time history in HyperGraph. Check/TH/SECTIO in Help which shows the outputs you can extract using this.
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