disla

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disla
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  • Hi JohnM, *GAP CONDUCTANCE can be temperature dependent. Have you try to switch on once you reach a certain temperature at the interface?. If you run a first analisys you could get the time_temperature evolution so CONDUCTANCE(Temperature) could b…
  • That happens for E values over 1E+13 GPa. You are using 1E+27 GPa as material property for S-Link-Rigido. That's unnecesary high?The elements freeze and nodal displacements are zero.
  • Did you had the change to open my file? Here it is again . Same config but with beam elements.
  • That's slightly different. Longitudinal restrain (x) is done at the Abutment and we have three beams not 1 deck. EDITE: FILE in LAst Post.
  • "The central beam has a hinge at the abutment " "Longitudinal bearing device at the pier , which prevents transverse and vertical movements. " Do you mean this "Longuitudinal bearing device" prevents only transverse and vertical but not longuitu…
  • "The central bearing provides both vertical and transverse restraint, while allowing longitudinal movement." "The longitudinal contraint is on the the bridge abutment" Then it's not completely free to move in x but must keep on top of bridge pier. …
  • "- The two outer bearings provide vertical support only , allowing horizontal movement. - The central bearing provides both vertical and transverse restraint, while allowing longitudinal movement." vertical (z) transverse (y) longitudinal (x) Brid…
  • I would model the finite dimension of the suporting base so the moment due to the excentricity of vertical load will emerge naturally.
  • @sofien_73 Look for NAFEMS Benchmark Challenge Number 2. Assessment of a Simply Supported Plate with Uniformly Distributed Load. I referenced it above. Read about the different Engineers approach to this subject , different element types limitatio…
  • From my perspective, two fundamental issues should be clarified before progressing further. Otherwise, there is a risk of developing the analysis around assumptions that may later prove inconsistent with the actual physical behaviour. 1. Boundary c…
  • 2 Simply supported isotropic plate under uniform load benchmark. Page 4/53. Authors. Biswajit Banerjee[1] Jeremy Chen, Raj Das, Anjukan Kathirgamanathan https://www.researchgate.net/publication/258848858_Comparison_of_ANSYS_elements_SHELL181_and_S…
  • By the way my file was originally based on a benchmark.
  • I can imagine how complex this sort of modelling must be, and how difficult it must be to anticipate all the possible combinations of load, directions… not to mention inertial forces, shock absorbers… phew. I suppose you have to strike a balance bet…
  • As for whether a human body can transfer moments, I would say that it can I would make a small distinction. Human Body can "induce" moment (by means of an offset force) but *distributing solve the static compatibility by means of a Force couple.…
  • I do not have experience modeling chassis, but I would like to add a comment. The solution with *Coupling + *Distributing depends on the position of the reference node. This is because the solution must be statically compatible with the applied lo…
  • -Isn't Cyclic symmetry and elastic supports on both symmetry faces redundant BC?. -I miss the internal pressure on the gasket it self. -There is an elastic support applied to the inside area of the gasket and bolt which seems unrealistic. -Symmetry…
  • I don't know how to output modal analysis results in this conditions @sofien_73 That should be under solution/MechanicalMisc/Modal effective Mass and Modal effective Mass fraction for a frequency analisys. I haven't tested on your problem so I …
  • According to the manual Mecway can also output the Modal effective mass fraction which is modal effective mass expressed as a faction of the total free mass.
  • Hi sofien, Based on this: ->reactions are the same (I assume you mean in the static solution) ->mode shapes and frequency are the same I can only think that you are using a larger number of modes for the modal superposition which would inc…
  • in S4R elements Comment by disla April 24
  • I don't use S4R at all. I have also found discrepancies with reference benchmarks when used for Buckling analysis.
    in S4R elements Comment by disla April 24
  • You can, but keep in mind you should set up the problem as nonlinear for accurate results if you expect large displacement. Main elements involved are rotating. Rotations---->NLGEOM. Check overall force balance.
  • No problem with your set up. This is a known limitation of the calculix S4R formulation. There is a strong shear MODE III present in the benchmark which S4R (Expanded C3D8R) is not suitable for.
    in S4R elements Comment by disla April 23
  • Hi, Sebastian, Have you take a look at Mortar contact?. I have obtain clearanes of 1E-35 with reasonable times. There is some limitations due to units conversion but results are really good when it works.
  • A good starting point is E*50 but there is no general rule. My recomendation if there could be one is to keep contact clearance at least of 0.1% of the caracteristic element size in the normal direction to the contact area.
  • All geometries have initial penetration. Some contact definitions are solved as an interference fit. take a look at the adjust parameter.
    in CXX Contact Comment by disla March 6
  • I'm in particular referencing to this convention. Are shears (gammas) , ccx output strains x 2 ? EDITED: SOLVED. I have seen in the FRD the value in the GUI is Twice the value in the FRD. Thanks. Is that for consistency with Openradioss?
  • @Sebastianmaklary Hi, I did not respond you just because I saw the Kuhl example file. Let me know if you need any further help. Regards.
  • Looks fine to me although the stiffness value of the base look unnecessary high. I guess you are looking for a hard contact behavior?. Note there is only compression in the part of the base that is pushed up and compressed against the base. Node…
  • Not the same. Let's see if I can explain with my poor English. ChatGPT doesn't understand me. An only compression support creates a set of elements in which the surface is supported. "Like" regular springs but nonlinear in this case. They only wor…
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