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  1. ssn3

    Direct cyclic theory

    Hi, I am not sure how many of you read the abaqus theory manual. If you read the theory manual on the direct cyclic algorithm they mention that the displacement response is a function of time, u(t). My question is how does it account for the displacements in different directions? Are these...
  2. ssn3

    How to obtain bearing stress?

    I am sorry I am new to abaqus. Are the CPRESS actually bearing stresses?
  3. ssn3

    How to obtain bearing stress?

    I have modeled a plate with bolts on abaqus and I wanted to know how to get the bearing stress in the plate hole. Is there an output to get bearing stress on abaqus?
  4. ssn3

    Finding global stiffness using abaqus

    If I were to use composite layups to set up my laminate is there an easier way to get the stiffness of the laminate?
  5. ssn3

    Finding global stiffness using abaqus

    Basically I am talking about the modulus in the 1,2 and 3 direction. I guess I should not have used the term stiffness.
  6. ssn3

    Finding global stiffness using abaqus

    Sorry if I was not clear enough. Lets say I have a composite for example with different plies stacked up. Since each ply has its own stiffnes (E1,E2,E3) and orthotropic the laminate itself can be estimated with a laminate stiffnes. In this case there will only be 1 set of E1,E2 and E3 for the...
  7. ssn3

    Finding global stiffness using abaqus

    Is there a way to find the global stiffness of the laminate for a given structure? I have defined a panel with sections of orthotropic material. I wanted to know if there is a way to obtain a global stiffnes in a particular direction for a structure with different orthotropic materials and...
  8. ssn3

    Output question

    Thank you very much.
  9. ssn3

    Output question

    I created a simple model to test this out. Using a orthotropic material I kept changing the orientation of the material. Based on this simple test I am pretty sure it gave results for E11,E22 and E33 based on the local material orientation. I used unique nodal position to get the output values...
  10. ssn3

    Output question

    I have a small question on outputs such as E11,E22,E33,S11,S22,S33,U1,U2,U3 etc. Lets say I have use an orthotropic material and have defined the different material orientations. The outputs I mentioned earlier, are they based on the global coordinate system or the local coordinate system that I...
  11. ssn3

    Direct cylic

    Thank you for taking time to explain to me. I appreciate it. I get a picture of how it works but I need to dig more into it. I want to truly understand how it all adds up. Thanks again for helping.
  12. ssn3

    Direct cylic

    You are probably talking about iteration. In a direct cylic analysis iteration is where the displacement corrections are affected. Because I am pretty sure that increments are time point in abaqus. At least that is what Abaqus says in its manual. In static analysis then yes increment is pretty...
  13. ssn3

    Direct cylic

    When you say increment what do you mean? Because from what I read increments are the time points used for the analysis. So if I use an increment size of 0.001, that would mean I have 1000 time points in a cycle.
  14. ssn3

    Direct cylic

    You are right I am basically confused on how the iterative scheme works. My understanding is that you have a curve for one cycle given an iteration. It continues to iterate until it converges for that cycle. Converges meaning the R and c entries are small. I am mainly confused about the R...
  15. ssn3

    Direct cylic

    I think I am beginning to picture it now. So for the next iteration how does the force residuals R differ? My understanding is that the displacements u change depending on the correction to displacement c. So how is the R going to change for the next iteration? Technically abaqus is still...
  16. ssn3

    Direct cylic

    So based on what you have said which ones are the knowns and unknowns? I'm guessing the displacements are the unknowns since that is what abaqus tries to obtain and the force are the knowns. Am I right?
  17. ssn3

    Direct cylic

    I read the manual and it says for direct cylic method it solves for u by using an iterative method. I just wanted to know how exactly is it solving for u. Which are the knowns and unknowns. Is it solving for unknowns based on simultaneuous eequations or what? That is what I need to know. So far...
  18. ssn3

    Direct cylic

    I just needed to know the theory part a little as I am a little confused on how it works.
  19. ssn3

    Direct cylic

    Hello, I wanted to know if anyone here could explain the direct cyclic theory on abaqus. So I read the abaqus documentation and wanted to know more about the direct cyclic algorithm. I was wondering if anyone could explain to me what goes on and how abaqus obtaines a solution. I believe the...
  20. ssn3

    Low cycle fatigue anaylsis

    Hello everyone, I have a small confusion regarding low cycle fatigue results on abaqus. I ran a fatigue analysis with displacement control on a structure and obtained the strain energy for the entire cycle using the history output. My question is why isn't the strain energy release rate a cyclic...

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