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msc

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msc last won the day on November 15 2016

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  1. Hi, is it possible to add the center of gravity and mass moment of inertia as information to the .out file? In my .out file only volume and total mass fo the model are output. Unfortunately - still after thorough checks - there is a mismatch between the volume and total mass which is computed via summary/moment of inertia template and the value in the .out file. That is why I expect a mismatch for the mass moment of inertia and center of gravity as well. Kind regards
  2. msc

    Error ID 556

    I am using OptiStruct but for geom. non-linear analysis of my model Radioss is used as the Radioss starter is run. How can I introduce the Spotflag=25 for TYPE2 in my input deck or via the OptiStruct GUI? I have found teh information SPOTflag=25 The main goal for interface type 2 using penalty method is to tie slave node to master segment without any kinematic constraints. Using the penalty method may avoid "INCOMPATIBLE KINEMATIC CONDITIONS". I have a lot of overlapping or adjacent Freeze Contacts for my linear static simulation in order to tie different parts together so often two or more interfaces share the same node and it is not possible to only define a slave node for only one interface as the error indicates. For OptiStruct this is not a problem but for Radioss apparently it is. Can I suppress this error somehow with introducing Spotflag=25 to my OptiStruct deck?
  3. Thank you, it works :-) Two more questions concerning non linear analysis: 1) How can I control the output increments for NLGEOM analysis (Geom non-linear (impl static))? The NLOUT parameter seems to work only for NLSTAT anlysis. 2) What is the difference between running a NLSTAT simulation and activating LGDISP and running a NLGEOM analysis? Is the stiffness matrix also updated during NLSTAT-LGDISP simulation? Are different solvers used? For a shell plate I get two different results as soon as I reach the buckling load...but the step sizes are different as well: With the same parameter NLPARM/NINC=20 which defines the first step size of 0.05 I get output 20 equidistant steps for NLSTAT-LGDISP, but only 13 steps for NLGEOM analysis. The time steps after reaching the buckling load are bigger for NLGEOM so it is hard to compare the curves as the output is not gained at the same time point.
  4. The slave-master definition is definitely causing my problem with Radioss...I will have a look at it and try to fix it. Can you tell me where to activate the NLOUT entry? It does not seem to be available GUI...I cannot find it in HM14.0 "The NLOUT entry can be used in the Subcase Information section to select the incremental result output parameters used for Nonlinear Static Analysis and Nonlinear Transient Analysis. " "The NLOUT bulk data entry defines incremental result output parameters for small displacement nonlinear analysis and large displacement analysis. "
  5. At several regions I have tied 3 parts together which means that one element (of component A) will be tied (freeze contact) to two other elements of components B and C. In OptiStruct 13.0/14.0 it works fine, but for geometric non-linear analysis the Radioss solver is used automatically. Maybe Radioss does not allow this definition, is that true?
  6. Yes, 14.0. So I should use non-linear static subcase instead of geometric nonlinear subcase? I will try. Btw, I have a modell with shell elements mainly. The documentation states that OptiStruct cannot perform large displacement analysis for shell elements. What should I do? Using Radioss? Is my OptiStruct modell fully compatible with Radioss?
  7. Can contact interfaces cause trouble? I am using Freeze contact to tie parts together but when I try to run a geometric non-linear analysis I get errors because of contact interfaces. Any clue? I have no problems with small displacement analysis, but only with large displacement analysis. Here one of around 800 identical errors: STARTER ERROR: ERROR ID : 556 ** ERROR IN INTERFACE TYPE2 DESCRIPTION : -- INTERFACE ID : 50 -- INTERFACE TITLE : INTER_TYPE2_50 MASTER NODE ID=97392 IS ALSO SLAVE NODE OF ANOTHER INTERFACE TYPE2
  8. Hi, I am struggling to do a global-local analysis by submodeling technique with OptiStruct. I have managed to run a local-global analysis with one model where the global structure is included as one component and the local structure is placed in another seperate component of the same model. But I don't like this approach because I don't want to store all local models together with the global model in one file because of display issues, mass calculation, handling/selection of elements, etc. As I want to use a refined mesh of a critical region of a structure I have two seperate models. How do I work with only one solver deck when global and local model belong to different model bases, respectively input files? How can I integrate/include them in the solver deck or even in the cards of the load steps? Or is there another way to extract the displacements of the nodes in the transfer zone of the global model and apply them directly to the local model.
  9. Does OptiStruct also support such a feature? I would like to apply some modes from a linear buckling analysis as scaled imperfection to my initial mesh for further analysis.
  10. Is it possible in OptiStruct to run a linear buckling analysis and to apply selected buckling modes with a scaling factor as initial deformation or imperfection for a non-linear analysis like in Abaqus?
  11. Can somebody provide me the complete page of the manual Prakash us showing in this thumbnail? I am using HW 13.0. but my documentation for CSTRESS ends with point 10...unfortunately Prakash is refering to point 11. I don't know how to introduce the NDVI option to the input deck (syntax, location within the code).
  12. Hi there, I would like to repeat this question: I have examined already 3 different models and the automatically calculated reference point NEVER matches the center of gravity of the structure. That is why the resulting accelerations differ from what I expect from manual calculations. Can you please tell me how OptiStruct calculates the reference point and how to make the solver set the center of gravity as reference point?
  13. And what about 1D-elements? I want to examine the Forces and Moments at the end point of a beam or at a connecting point to other beams...so I need the data in the node of a beam element and not the average result. Is this possible to obtain?
  14. Thank you, that would help me a lot. I am using the lastest version 13.0 but in the OptistrucHelp under CSTRESS I cannot find the information you have shown....there are just additional 10 comments for cstress...but your screenshot shows that NDIV is refered to in commet no. 11....I don't see that. In the control card of cstress I only have the options FORMAT,TYPE and OPTION. I work with ply-based modelling with PCOMPP cards. I have tried to edit the .fem (I am using OptiStruct) file and updated the line to CSTRESS(H3D,NDIV=2) = ALL but nothing changes...I still get the results of the midplane only :-( How can I set this? P.s: Optistruct Input Deck Generated by HyperMesh Version : 13.0.0.119
  15. How can I obtain corner results for composite stresses? I only manage to iobtain them for element stresses (2D) which is not what I want when working with composite modelling. And is it possible to obtain corner data (Forces, Moments) for the nodes of a 1D-Element (cbar, cbeam, crod)? I only get the average result of the element but what I need is to read the Forces and Moment et the connecting nodes (not averaged).
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