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  • in reply to: Thermal load on shells: #5080
    Luciano Jacinto
    Participant

    I understood your response. So, I run again the model with a zero Poisson coefficient (turning strains in both directions independent from each other) and got the same high result (sxx = 11805 kN/m2). So, the question seems a bit more complicated. I’m not an expert on FEM, but, perhaps it has to do with the shape functions, as you said. Thanks for your time spent on this.

    in reply to: Thermal load on shells: #5077
    Luciano Jacinto
    Participant

    Many thanks for your help. Ok, it makes sense that for shell elements NextFEM applies uniform temperature gradient simultaneously in both local directions. Ok, in my example, a monodimensional element would be more suitable, but this was simply to test NextFEM regarding uniform temperature gradients in shells.

    So, continuing with my test, I corrected the model freeing displacements in the z-direction, and, after the analysis, the model behaves as expected, except for stresses in x-direction. NextFEM gives sxx = 11805 kN/m2, but I expected sxx = 7869 kN/m2. I would expect a closer result.

    Once more, many thanks for your fast response.

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    in reply to: Linear elastic modelling of a slab #5050
    Luciano Jacinto
    Participant

    Dear NextFEM admin and parhyang: Thank you both. Definitely, to estimate negative moments with some confidence in slabs at continuity supports we have to use finite elements with very small size near the supports (size in the order of magnitude of the slab thickness).

    in reply to: Linear elastic modelling of a slab #5043
    Luciano Jacinto
    Participant

    Many Thanks for your very fast response. Thanks also for the free, basic version of the program. What I like best is its very simple interface with Python, making it possible to construct a model in few minutes (using templates). For me, the GUI is good to view results, not so much to build the model.

    So, we may conclude that, although the implemented finite element has the advantage of avoiding stress concentrations and peaks (which is the case in many situations, for example concentrated loads on shells), if there is some real peak, we must use a refined mesh, with very small size.

    in reply to: Temperature gradients #4807
    Luciano Jacinto
    Participant

    Thank you very much for the update. I’ve just tested the method addThermalDistLoad() in several beams (doble-fixed, fixed-supported and continuous) and everything worked as expected, both uniform gradient and linear gradient. Congratulations!

    in reply to: Temperature gradients #4799
    Luciano Jacinto
    Participant

    In the case of uniform gradient the result given by NextFEM (compression) is obviously correct. The doubt is only about linear gradient.

    in reply to: Plane frame, linear static analysis #4761
    Luciano Jacinto
    Participant

    Thanks. This time the solver ran the model without problems and the results were as expected.

    in reply to: Generate a mesh specifying the contour #4755
    Luciano Jacinto
    Participant

    Thank you very much!

    in reply to: Non-uniform distributed loads on line elements #4748
    Luciano Jacinto
    Participant

    Congratulations for the 2.2.0.5 release. I made some tests, and everything seems work perfectly. I also notice that it was made an improvement in API for Python. Now we can specify several load values and the corresponding positions:

    nf.addBeamLoad(
    elem = e1,
    values = [0, -12, -12, 0],
    positions = [0.0, 1.0, 4.0, 5.0],
    direction = 2,
    loadcase = ‘lc4’,
    local = True,
    )

    Is there a change log so that we can look for the improvements in each release?
    Thanks for this very nice program.

    in reply to: Non-uniform distributed loads on line elements #4747
    Luciano Jacinto
    Participant

    Thak you very much. I will look forward for the new release.

    in reply to: Non-uniform distributed loads on line elements #4744
    Luciano Jacinto
    Participant

    Sorry, but the problem with non-uniform loads on beams persists. For a simple supported beam with a span of 5 m and a triangular load, 0 at the beginning and 12 kN/m at the end, the moment at the mid-span is 18.75 kNm, but the program gives a strange result (a negative value!). Please verify this. Thanks.

    in reply to: Non-uniform distributed loads on line elements #4742
    Luciano Jacinto
    Participant

    Many thanks for your quick reply. The problem is solved. I will continue to test NextFEM, which seems to be a very interesting program: simple and powerful.

Viewing 12 posts - 1 through 12 (of 12 total)