Learning Forum

[ciema]

Hello, I cannot plot stresses for BEAM4 elements.

Here is what I've done:

• this is my 1D beam element

[Erik Kostson]

I have not used this element inside workbench, but the comments below might help.nnFirst, see the help manual (element reference) for beam4 element and the result outputs.nnYou would need to use probably the SMISC an NMISC in the user defined results that you create in mechanical.nnSee for instance below where we plot the bending moment about Z.nnn

[ciema]

Many thanks for reply ! The problem is that I've checked information contained in help and tested many of those result combinations, but I cannot get proper results - for example when force 1000N is applied on the end of my beam I receive:n nnI think it should be connected with something else... n

[Erik Kostson]

Please read through the help on beam4.nnThe SIMISC6 is moment about the Z axis which is the axis where my moments are about.nnOne can look at other things/outputs like maximum combined stress (axial+bending - smax) which is NMISC1 or NIMISC3 - see help manual for more info on this.nnAlso we would recommend using the latest technology elements and not legacy beam4.nnAll the bestnnErikn

[ciema]

Okay, but can you tell exactly which element can replace beam4 which purpose here was to implement Timoshenko beam?n

[Erik Kostson]

Use beam188, that is the element that is recommended - beam188 is based on Timoshenko theory.nnSee help manual for more info.nnAll the bestnnErikn

[ciema]

Once again thank you for reply. If BEAM188 is based on Timoshenko theory, why I receive this result (please see cross section shape and orientation):nI have checked element matrix and BEAM188 are used.nWhen I use BEAM4 I can obtain the following result: nSo BEAM188 does not produce a valid result for men

[Erik Kostson]

OK, you must have set the deformation scale to more than one so this is not the true deformed scale (set Results to 1.00 True Scale - that is the only one meaningful especially for large deflection analysis). See this for more info:https://forum.ansys.com/discussion/14332/deformation-scaleWe need to compare the actual deflection (16 mm) and not the post processed contour of the deformed beam under exaggerated . Also I would not look on the contour plots of the beam4 since workbench post is not build to post process a beam4 element really. We can still use the actual nodal displacement values they are meaningful.nnThank younnErikn

[ciema]

True Scale Results:nBEAM188nnBEAM4nnnIt is clear that BEAM188 does not behave in accordance with Timoshenko theory, but thanks for help anyway.n

[Erik Kostson]

HinCan you expand and explain what you mean with it does not behave in accordance to Timoshenko theory? (have you compared the displacements with that theory (say analytical solution)nnIf it behaves or not, then you would need to compare the deflection of ~ 16 mm to the analytical solution for a Timoshenko theory, have in mind that it would need to be nonlinear theory since your displacements are very large compared to the beam dimensions.nnIf you want to see if it behaves like expected I would do a benchmark against Timoshenko theory but for small deflections (so linear theory).nWe do have also many benchmarks which you can find in our help manual:nVMMECH049nVMMECH029nnAlso we said that we should not really look and use the 3D contour plot of the beam4 element since it is not supported in WB/Mech.nHope this helpsnnEriknn