[parhyang]

hi, let i share experiences of p-delta analysis in NextFEM: large test i took has shown all results in good agreement with another FE software i.e SAP2000/Etabs, Mastan, STAAD, RISA. Only some minor discrepancy is in shear force distribution curve, OOFEM solver can consider shear deformation (Timoshenko) but OpenSees can not.

[parhyang]

actually limit number of stations are available, so many thanks.

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[parhyang]

thanks for explanation, add number of stations may help for this. Maybe in setting option menus, it allows for 10 divisions instead of 20 to make it less dense.

[parhyang]

thanks for the hints of work around for element stiffness modification. Maybe, it can be useful when allowed to input as formula, e.g =0.00026667*0.7 to easily remember and modify.

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[parhyang]

great news it has been implemented, only in plot results has problem, and it will be fixed in next release. i checked again for OpenSees solver by exclude/deactivated shear deformation and i can confirm also, so many thanks.

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[parhyang]

thanks for clarification, hopefully there’s improvement in future versions. Meshing of single quadrilateral shell element (arbitrary geometry nodes) by edge division is a common task in structural modeling.

[parhyang]

thanks, there’s placed at another menus even it seems not exactly the same. Element stiffness modification of beam or shell element can be assigned independently of axial, flexure, torsion and shear e.g 1.0A, 0.7I, 1.0J, 0.7As

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[parhyang]

thank you for clarification and hints, probably my previous successful running are disabled in shear deformation of beams in solver preferences.

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[parhyang]

i miss to inform, switch to OpenSees solver displaying value of end_j shown as expected. Thank you.

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[parhyang]

indeed, probably related to “More output stations” setting and plotted result shown all beams are always active by default (attached).

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[parhyang]

i tried again by creating new model of simple plate, assign loads, mass source then running analysis. OpenSees executable from official webs seems to be failed and crash, but alternates executable provided has not. Displacement and internal force results of static and dynamic modal analysis shown properly, consistent with OOFEM solver also. Once more, thank you so much. Please add a mirror link at GitHub if possible, since another user may experience the same issue.

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[parhyang]

hi, let me add to discussions. It’s commonly doing mesh refinement at high stress/force areas only, below an example.

i reproduced a model using GUI, start from node by coordinate, draw single quad element, mesh uniformly then refined. Solver being used is OpenSees, rerunning with OOFEM given identical results.

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[parhyang]

hi, much thanks for given alternative distribution of OpenSees, It solved properly in static and modal dynamic analysis, displacement result in NextFEM shown as expected and consistent with OOFEM solver except in shell area force. I did not know in detail, since running single analysis of plate static analysis seems not a problem. i will try to do comparison with old versions of OpenSees also.

[parhyang]

thank you for looking further into my problem (attached input files). Installing Tcl 8.6.10 version make OpenSees works normally for static analysis of 3D frame as can be seen in example figure below. However, the problem still persists for plate models in both modal and static analysis.

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[parhyang]

thanks for confirmed it should work properly also in latest version, i will continue in installation problem of Tcl versions exactly.

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