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Recent content by ctmfab

  1. ctmfab

    FEA of welds

    I'm not sure what code you are trying to satisfy, but from the pressure vessel industry here are a few comments. Got a bit long winded, but I consider fatigue prediction one of the less accurate parts of our work. We typically tell people during seminars... "The good lord watches over: 1...
  2. ctmfab

    FEA Mesh Software

    Bobfromoh - I'm not trying to advertise or sell here, but this sounds like what you are looking for..... An AutoCAD interface is currently under development at Paulin Research Group that will allow users of FE/PIPE to generate axisymmetric, shell, plate, and solid models for any geometry...
  3. ctmfab

    Define Pressure Vessel

    Generally, all the following must be met for the component to be designed as a piping component. If ALL these are met it can be designed as a piping component, if not ALL are met it could be designed as a pressure vessel. 1. It can be described by a piping sketch or iso drawing and...
  4. ctmfab

    RISA 3D analysis

    The latest version of Risa 3D uses "physical" members that will automatically attach themselves to the intermediate nodes. So, you no longer have to break a continuous beam at the various nodes along it's length. However, the unsupported length used in the AISC calcs will be set...
  5. ctmfab

    Problem : Tank lifting as per appendix J

    Your primary concern is to provide a nominal safety factor against failure due to excessive plastic deformation of the lifting lug. Thus, to prevent plastic deformation of the lifting lug you do not want to exceed the yield stress. API 8A and ASME B30.20 both limit the allowable stress based...
  6. ctmfab

    UT instead of X-Ray

    See Code Case 2235 for UT in lieu of RT. This code case defines under what applications UT may be used in place of RT.
  7. ctmfab

    Handling Large Stiffness Matrix

    Thanks for the input from everyone. The start of this little project is to create a parametric modeler to model smaller geometries in 2D. This way I can model up to about 500 nodes even if no improvement is made to the solution algorithm. However, this would be incredibly slow so I won't...
  8. ctmfab

    Handling Large Stiffness Matrix

    Does any know how to handle very large arrays or matrices in VB6.0. I get a memory error when using arrays that are of several thousand terms. (ie 3000x3000). This is for math calculations for stiffness matrix of steel structures. I have seen suggestions to use an array of arrays. In other...
  9. ctmfab

    Large Stiffness Matrix

    Does any know how to handle very large arrays or matrices in VB6.0 (or any programming language). I get a memory error when using arrays that are of several thousand terms. (ie 3000x3000). This is for math calculations for stiffness matrix of steel structures. I have seen suggestions to use...
  10. ctmfab

    Pressure vessel vs. piping

    Generally, all the following must be met for the component to be designed as a piping component. If ALL these are met it can be designed as a piping component, if not ALL are met it could be designed as a pressure vessel. 1. It can be described by a piping sketch or iso drawing and...
  11. ctmfab

    FEA Programming

    Bhat165, Thanks for your help. I actually saw your suggestion for Numerical Recipes in another post. This is a very helpful reference and contains lots of theory and practical methods for coding your own program. I agree that there is no single algorithm and that copying code is the wrong...
  12. ctmfab

    FEA Programming

    I am looking for any books with a focus or chapters on FEA programming (or any reference). That is, any with examples or methods shown in theory and code. I am writing a simple program to solve truss models to further my understanding of the methods. Any language is fine, but VB is what I am...
  13. ctmfab

    Skirt Bracing

    Does anyone know of any references for design of skirt bracing to accommodate lifting/shipping loads? Most of the methods I have seen use Roark's equations for stresses in rings. I have seen two methods that seem reasonable. First, the weight is distributed as uniform vertical load around...
  14. ctmfab

    Flat bottoms in ASME BPV VIII???

    WIth proper judgement, the vessel you described can be built to ASME Section VIII, Division 1, but not be stamped. The reason is that the design pressure specified (10 psig) is outside the scope of ASME Section VII Division 1. The design pressure must be equal to or greater than 15 psig. See...
  15. ctmfab

    Vessel engineering software

    I have used APV, PV Elite, Compress, and Disasu. APV, PV Elite, and Compress are good programs. Compress seems to have a few more abilities than APV or PV Elite and would get my recommendation. APV is a good program, even better since converting to a windows based application. They have...

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