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  1. gwena

    Adams Flex

    I solved the problem 2 nodes with 'MASS 21' was created. This concentrated masses are constrained with a set of nodes at each extremities (CERIG option). I set the real constants of the mass21 to 1E-7 in order to not disturbe the global mass. The bug was that I wrote 1E-1 in one of them...
  2. gwena

    Adams Flex

    Hello, I'm using AdamsFlex. I meshed the flexible body with Ansys and imported the .mnf file in Adams flex. The problem is that : The weight of the flexible body is 0.064kg in Ansys whereas its mass is 0.260Kg in Adams ! The correct mass is the first one. Units are specified in SI (MKS)in both...
  3. gwena

    riks - critical load

    ok. This means that applying a displacment condition, the reaction force that I will read will be the real critical load. Thanks !
  4. gwena

    riks - critical load

    Hello, There is something that I don't understand about the determination of the critical buckling load. The method is : 1) Perform a linear analysis to have an idea of the critical load and its associated mode. 2) Introduce a perturbation in the geometry (*IMPERFECTION) 3) Perform a...
  5. gwena

    logarithmic meshing

    Someone knows how to generate a meshing with a logarithmic bias along the length of a body ? I want to refine it. Thanks !
  6. gwena

    How to keep 2 surfaces parallel during a simulation?

    May could you put boundary conditions in order to fix a rotation ?
  7. gwena

    linear buckling analysis versus preload frequency analysis

    So, now, theory is ok. But in practice, what's wrong ? I tried to include *INITIAL CONDITIONS,TYPE=PRESSURE STRESS but it doesn't change the result. ...
  8. gwena

    linear buckling analysis versus preload frequency analysis

    The problem of finding natural frequencies of a structure can be solved using the mass and elastic stiffness matrices of the structure. On the other hand, the problem of structural instability of a structure and the critical buckling load is a problem, which can be solved using the elastic and...
  9. gwena

    linear buckling analysis versus preload frequency analysis

    Hello, There is something that I don't understand. A linear analysis of buckling (BUCKLE card) is solved by the research of the load for which the stiffness matrix become singular. Thus, an eigenvalue analysis with various preloads should be another way to verify the critical load. The value...
  10. gwena

    buckling

    Great ! Conclusion is that spaces from the beginning of lines are dangerous !? It's exactly what I want to verify : Buckling in a bending mode because of the bending moment. Thanks a lot !
  11. gwena

    buckling

    Here it is ! Thanks a lot for any help! *HEADING TORSIONAL BUCKLING *RESTART,WRITE *parameter R1=0.0359 L=0.6 p=0.060 PI=3.141592654 THETA=(p/R1*180/PI)/2 thickness = 0.0002 BETA=-90-THETA BETA1=-90+THETA node_circum=71 node_length=71 node_tot = node_circum*node_length node_int =...
  12. gwena

    buckling

    I tried it with S4, S4R5, S8R5 and also STRI3. But not with S9R5. It should work with a simply S4R5 ! ... Gwen
  13. gwena

    buckling

    Only the last row of elements at the free end is deforming but I know that the deflection has to be global in a bending mode. I didn't specific that is a curved thin strip. Gwen
  14. gwena

    buckling

    First, thank you for your response ! Unfortunately, I didn't solve my model. As you said, I tried it with 10% of the buckling load and I put the RIKS method off but it doesn't work. I tried it with the stabilize option too and with a displacement control but the problem is the same. I don't...
  15. gwena

    buckling

    buckling I'm doing a non-linear analysis in order to perform buckling of a strip. One extremity is clamped. The second one is free and a load is applied. The linear buckling analysis was ok. For the non-linear one, using S4R5 elements, *STEP,NLGEOM,INC=500 *static,riks ... adding an...

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