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Recent content by drennon236

  1. drennon236

    Euler and Global/Local Buckling

    I was trying to find out what Global Buckling is, and someone defined it as: "Global buckling is classical Euler buckling. This has to do with the “global” cross-section properties (EI) and the beam/column unbraced length “L”." I understand Euler Buckling load can be found with the help of...
  2. drennon236

    What is stress stiffness matrix?

    This is a FEA buckling problem, and I am not sure what is meant by stress stiffness matrix and elemental stress stiffness matrix?
  3. drennon236

    How does the strain tensor differ for a homogeneous vs nonhomogeneous material?

    If for example the homogenous material is not subjected to any load, deformation or anything. While the nonhomogeneous material is subjected to gravity,and every other type of force you could imagine. How would the strain tensor differ for the two cases? Would it all just be zero for the...
  4. drennon236

    What is meant by point group symmetries of a cube?

    I think I get it now, by operations of symmetry a cube can be built from the highlighted figure in (c).
  5. drennon236

    What is meant by point group symmetries of a cube?

    I am reading a paper related to microstructures, and it says a unit cell has geometric cubic symmetry. When I tried to google the meaning it said: "The symmetry group of a cube is isomorphic to S4, the permutation group on 4 elements." Which tells me basically nothing as this is not my field...
  6. drennon236

    Do these mean shear and stress in the respective directions?

    The first three mean stress in the first, second and third direction, for example in the x, y and z direction: What would the last three numbers mean -(23,32) , (13,31) , (12,21)? I understand that they represent shear, but how does it work with directions? Are there any good illustrations...
  7. drennon236

    What is meant by "small deformation assumption" ?

    Is this somehow related to using small angle approximation (sin θ ≈ θ)?
  8. drennon236

    What is meant by "small deformation assumption" ?

    What is small deformation assumption in this text? LB analysis = Linear Buckling analysis
  9. drennon236

    Trying to understand how the The Arc Length Method works

    This is how a paper describes it: Is this what they are talking about? I found this youtube video seperately, I am not sure if what is illustrated below is the same as the text above talks about. https://www.youtube.com/watch?v=j4IaRcUM0Mk
  10. drennon236

    Does anyone have an idea why I might be getting this error message in COMSOL?

    And is it in any way similar to slave/master surface in abaqus?
  11. drennon236

    Does anyone have an idea why I might be getting this error message in COMSOL?

    Is there anywhere I can check what the source and destination are defined as?
  12. drennon236

    Does anyone have an idea why I might be getting this error message in COMSOL?

    I have been given a model that is used to model a unit cell representing a large repetitive structure by using "Cell periodicity function" - which calculates the effective material properties of said structure. Error message I get if "parametric sweep" function is turned off. Boundary...
  13. drennon236

    Does anyone have an idea why my model might not be running? [COMSOL]

    FEA way I have attached what I found under Fixed Constraint, tried to place it around the model but didnt seem to help much. engineering_patrol, do I need livelink Matlab to see this stiffness matrix?
  14. drennon236

    Can you calculate dimensions knowing the volume fraction is 0.2?

    I am going to model this in a FEM programme (COMSOL), and for computational reasons the symmetry is fully exploited. Picture 1 is a cubic lattice structure, its supposed to be a small part of a major repetitive structure. Picture 2 is picture 1 even further simplified (imagine picture 1 being...

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