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

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Nachiket Kadu

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Everything posted by Nachiket Kadu


    Hi Did u check the element quality?
  2. Hi I am trying a interference fit problem with rather a simple problem. The line diagram for which can be seen. I am evaluating the reaction forces, and it can be seen that it abruptly changes the sign and magnitude at some instances. There is no such abrupt changes in energies, just forces are changing.I have attached out file for the same. Kindly give your valuable suggestions. interference_0001.out
  3. Improper force pattern for interference fit problem.

    Hi George I forgot to mention one more issue. While exporting the engine file i got this message "Save invalid elements to user mark". Till now i dint get this sort of message. Kindly suggest me something about this matter.
  4. Improper force pattern for interference fit problem.

    Hi George Hope you got the files.
  5. Improper force pattern for interference fit problem.

    Hi George Yes , with output block as REACY
  6. Compliance in out file for static analysis

    why compliance is being multiplied by 0.5 factor?
  7. I need some clarification for my doubt regarding calculation of compliance in.out file of static analysis. If possible i request you to send any theoretical background for compliance calculation. 1. Compliance value comes in terms of (100 or 1000) , reciprocal for which will be in terms of (0.001 or 0.0001)which we call as stiffness. This much less stiffness will be there for any model? 2. In static analysis when you increase the force the deflection will increase proportionately i.e. F/d term will remain constant but with change in force i am getting different compliance values. 3. I am following Tonnes,mm,N unit system according to which stiffness unit should be N-mm so the unit of compliance will be (1/N-mm) is it correct? I tried on a simple beam the out file and HM file for which is attached here. I request you to kindly help us through this. For_force_5.out as.hm For_force_10.out
  8. Compliance in out file for static analysis

    Hi Prakash Thanks for replying, So what this compliance stands for? Can it be basis for my compliance optimization? My aim is optimization, but before proceeding for that i need to know the calculation for compliance and its relation with the actual stiffness. If you could provide me with any source of information that will be really helpful.
  9. Different displacement results between optimization and analysis

    Hi Prakash Thanks for replying, you can also see that though it is a maximization problem the mass seems to be decreasing upto a great extent. I have one more doubt, in maximization problems, element with element density=1 suggests addition of stiffness to that region?
  10. Abbreviations

    Hello STFEXP stands for exponential penalty for contact stiffness and can be used to maintain the continuity of open and closed nature of contact stiffness.
  11. Different displacement results between optimization and analysis

    Hello Can anyone clarify doubt regarding the above comment?
  12. Different displacement results between optimization and analysis

    Hi Prakash I was going through similar problem here, i am performing maximization of frequency by increasing volume fraction (taking shield example in tutorial as basis). The optimization results show a lower value of frequency so i kept MATINIT=1. The initial frequency (at 0 iteration) came closed to actual natural frequency but as the analysis proceeds the frequency instead of maximizing tends to lower down at first few frequency and again increases to the almost the initial value of frequency. For your reference i am attaching the .out files kindly compare and suggest your views. upper bound value of vol_frac=0.4 Original frequency=23Hz Final Frequency obtained using matinit as 0.6= 23Hz (Mass=154 Kg) Final Frequency obtained using matinit as 1= 22.9Hz [Initially (at 0 iteration) 167 kg and get reduced to 154 Kg] Trough_Opti_without_matint.out Trough_opti_with_matinit_1.out
  13. Basic Solid Linear Static Error

    Press F2, select elements by config => select quad4 for quad elements and tria3 for triangular elements and delete the selected elements.
  14. Basic Solid Linear Static Error

    Hi You must have converted shell elements into solid elements, check whether you deleted shell elements or not? If not kindly delete shell elements.
  15. Equvivalent elements for welding.

    Hello, As you can see in line diagram there are 2 plates 1 and 2. Plate 1 has a circular hole in it. Plate 1 is supposed to placed on plate 2 and arc welded on the inner circumferential region of plate 1. The weld is such that the whole circular area is filled with weld in real time situation. I am proceeding with vibration analysis and dont want represent this weld by rigids (RBE2). Any ideas how i could represent this welds for vibration analysis??
  16. Equvivalent elements for welding.

    Good Morning Agreed but this can be done when the plates are solid, while dealing with mid surfaces equivalence will distort the elements.
  17. Equvivalent elements for welding.

    Hello, @Q.Nguyen-Dai U mean to say after creating coincident mesh i should connect node to node using beam/rod elements? If so whether i should consider a washer also or just node to node on circumference of the circle is enough?

    Hi Prakash As you said gravity loading doesn't work with tload1, but what if we keep the type of load default instead of defining it as acceleration. I think this could work.
  19. Plastic strain

    Hi You are saying this for only brick elements or solid elements in totality? What is B2B u are referring here?
  20. Plastic strain

    Hi Kindly check for material card Mat S1, whether you have mentioned Plastic or NLelastic. For NL elastic i guess it wont show plastic strains.
  21. Problem in Run

    I think changing time step wont work here because the system calculated time step is much higher, so solver will try to choose maximum of the system calculated and user fed.
  22. Problem in Run

    Further, I would suggest you to follow tonne,mm,ms system.
  23. Problem in Run

    Hi Harsh The problem is with rigid element. just try to give rigid on outer surface and run the simulation.
  24. Problem in Run

    Hi Harsh If you could see your DT is very high. What material you are using? Kindly verify your units.
  25. Hello Prashant Sir Any solution for the said problem yet?