Learning Forum

[ebone2god]

Hello,nI'm trying to extract a response PSD at a beam node. I have simple beam model with spring-connections at each end that I am trying to use for a random vibration analysis. I've run my modal analysis, requested stress, strain, nodal force, etc. from the modal run, and I have my acceleration PSD added. nSome of the issues I'm running into are that the stresses and strains for the model cannot be plotted (no option to add and the beam tool is greyed out) and that I can't specify a response PSD output on an intermediary node on the beam; only the end vertices. One workaround for the PSD could be that I split the beam element in two, share topology, and get a response PSD at the new vertex, but I was hoping that there's a simpler way to select nodes that I'm not seeing.nCould anyone suggest any ways to get this response PSD using beam nodes? I would appreciate any help!nnEdit: I meant to specify, I am going through this workflow in Workbench.n

[Ashish Khemka]

nnIf you know the node number then you may use the command object to get the result. Please refer to the following example, from which you can copy the post-processing commands into Mechanical:nnnRegards,nAshish Khemka

[Chandra Sekaran]

Hi, for beams most of the element results are accessed through ETABLE items. The ETABLE items are listed in the Elements reference manual for each element type, You may need to use command snippets such as below to access this data and do response PSD calcualtions.n/POST1nset,3,1n/show,pngnetable,sxyt,smisc,32 ! store bending stress for modelnpletable,sxytnFINISHnn/post26nstore,psd,10nnesol,2,5,,smisc,32 ! store bending stress at Y top for beam element 5 in variable 2nrpsd,3,2 ! create response PSD of variable 2 and store in variable 3nnplvar,3n/show,closen

[deltav]

Hi,I have a question which goes in the same direction. nI ran a random vibration analysis in Workbench and I need to export the acceleration response PSD for a number of nodes automatically via APDL.nnSo far I always right clicked on the table results and exported the table manually. nHow would the equivalent APDL code look like?.I tried to adapt your code snippets but only received zero vectors in my written output file. nHelp would be really appreciated!nn