Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. SWComposites

    Tria/Tetra vs Quad/Hex

    3 node triangles are not good. 4 noded tets are very bad. avoid both. auto meshers create triangles/tets because it is "easy". grrrrrr.
  2. SWComposites

    What boundary condition techniques do you use to keep FEA models realistic?

    other than the 3 simple examples you list, there aren't any general simple rules. have to look at the actual structural connections, and ensure that the BC's are realistic and appropriate for expected structural behavior. common mistake is to over constrain the model, by using rigid BC's or...
  3. SWComposites

    1/2 loading for 1/2 model in ansys?

    seems like you would be applying internal pressure loads. can you show the actual applied loads on the entire vessel. probably don't scale the loads, but apply that loads that are on the half that is modelled. but the boundary conditions at the symmetric plane can be complicated. might be...
  4. SWComposites

    Design tools

    https://espcomposites.com/software/software.html
  5. SWComposites

    Thermal load with thermal gradient in a structure analysis with FEM

    please do not double post.
  6. SWComposites

    Defining joints

    suggest you delete this post and repost in either the Finite Element Analysis forum or the OptiStruct forum (if it exists). This forum is mostly Civil Structures engineers.
  7. SWComposites

    FEA Adhesive Modeling

    VCCT and Cohesive Zone models have both been used to predict bonded joint strength. Abaqus has elements for both approaches. You will need test data to a) determine and calibrate the input properties, b) to validate the joint strength predictions. What are your adherend and adhesive material...
  8. SWComposites

    Mastering FEA: How to Get Through Stage 2 (Developing Good Modeling Techniques)?

    Beams are not that complex. Boundary conditions can be complex and difficult to approximate. Stress concentration areas can be complex to model (its often best to not model these in detail, but to extract far field forces and apply classical stress concentration factors or other analytical...
  9. SWComposites

    Mastering FEA: How to Get Through Stage 2 (Developing Good Modeling Techniques)?

    Re rb’s last comment. Exactly. You have to know how to do proper structural analysis before you start using FEA. Generating millions of element results for a thousand load cases is not helpful if you don’t know what to do with the results.
  10. SWComposites

    Mastering FEA: How to Get Through Stage 2 (Developing Good Modeling Techniques)?

    You learn by doing. And making mistakes. And getting advice from peers and more experienced engineers. You learn the most by working on real problems. And by correlating analysis predictions to test data. And realize that FEA is just a tool in the tool box. Like any tool it has its uses. And...
  11. SWComposites

    FEM Contact Analysis Variables

    I have never seen a tested lug fail in bearing at the side of the hole. So a predicted peak bearing stress there makes no sense.
  12. SWComposites

    How to Integrating the shear stress of the cross sectional area to find the moment M?

    huh? what? are you talking about beam analysis? if so you integrate the shear down the length to get the moment distribution down the length integrating the shear stress thru the thickness of the cross section is something else. start over with a lot more details about what you are doing. and...
  13. SWComposites

    Why the symmetrical structure under self weight has unsymmetrical deformation?

    there has to be something about the mesh, material properties, loads or boundary conditions that are not symmetric. show us pictures of the loads, boundary conditions, etc
  14. SWComposites

    Modelling clearance holes MSC Nastran/patran sol 400

    why in tarnation do you want to model the fastener holes? you are not going to get a correct local stress distribution with RBE3 or RBE2 connections to the holes, nor even if you try to incorporate contact between the fastener and hole. just eliminate the holes in the model, connect with...
  15. SWComposites

    CBUSH coincident nodes in hypermesh?

    Do it in Excel. Output all of the node definitions - ids and coordinates Sort by coordinate locations. Coincident nodes should be adjacent. Create CBUSH cards in Excel using character strings. Out CBUSH cards and read into Hypermesh.
  16. SWComposites

    Proper way of extracting component and bolt forces in an assembly

    If you are modelling the bolts with solid elements, well, to be frank, that is gross overkill and its not going to be accurate anyway. All it does is make for a very complicated model and will generate lot and lots of output for which you won't know what to do with. What are you going to do...
  17. SWComposites

    Proper way of extracting component and bolt forces in an assembly

    are you going to model the bolts with solid elements? or are you modelling the bolts with bars/springs/etc? are you going to attempt to model the fastener preload? which is quite difficult. there have been many thousands of aerospace fastened joints analyzed with FE models with simple fastener...
  18. SWComposites

    Proper way of extracting component and bolt forces in an assembly

    If you are gapping the joint you do not have a good joint design. Either increase fastener torque, or add bolts, or something. You can use either one or two models, just have to consider the limitations of each. Both are an approximation to reality.
  19. SWComposites

    MSC NASTRAN for ABAQUS CAE

    you will need to use Nastran Sol400 for this nonlinear analysis. However, I strongly recommend using Abaqus.
  20. SWComposites

    Methods to add rotation dof to solid with ABAQUS, MSC NASTRAN and SAMCEF

    Google "transition from solid elements to shell elements" - there is lots of info out there

Part and Inventory Search

Back
Top