Dear XAnsys members,   I need to calculate "factor of safety" for a brittle material using "elemental" max. principal stress. Since the default "factor of safety" is based on "nodal" stress. I'm planning to use "user defined results". But I only need to extract the positive max. principal stress neglecting any negative values.  How can I do it? I'm using ANSYS Mechanical workbench.   Thank you. BR, Rashiga Research Assistant Korea University of Technology and Education  South Korea    

You are probably going to have to do something like "max(0,S1)". This will get principle stress 1 at each node and clip it to always be greater or equal to 0. If you want to view the actual nodal values make sure you select "unaveraged" instead of "averaged" which is the default. Something must be set at every node so it is not possible to just not display negative values. If you want to clean up the display a little you could use capped iso. Neil Dencklau University of Minnesota On Sat, Feb 23, 2019, 2:29 AM "라쉬" <rashi@koreatech.ac.kr> wrote: > Dear XAnsys members, > > I need to calculate "factor of safety" for a brittle material using > "elemental" max. principal stress. Since the default "factor of safety" is > based on "nodal" stress. I'm planning to use "user defined results". > But I only need to extract the positive max. principal stress neglecting > any negative values. > How can I do it? I'm using ANSYS Mechanical workbench. > > Thank you. > BR, > Rashiga > Research Assistant > Korea University of Technology and Education > South Korea > > > _______________________________________________ > Xansys-temp mailing list > Xansys-temp@xansystest.info > http://xansystest.info/mailman/listinfo/xansys-temp_xansystest.info > If you are receiving too many emails from XANSYS please consider changing > account settings to Digest mode which will send a single email per day. > > Please send administrative requests such as deletion from XANSYS to > xansys-mod@tynecomp.co.uk and not to the list >

If you don't need visualization, only the data to calculate the safety factor, you can export the values per node and per element by right-clicking the result, Export and then text-file. It will open on Excel as a csv file. There you can do your calculations easier, including filtering out negative values. Atenciosamente, Best regards, Tiago José Medeiros de Araújo Lira Engenheiro Mecânico Mechanical Engineer [cid:0x4f771ab.0xe1519fa3.0x21d70a5.0xf5e1d87d1ef255939f2706bb] Fone (Phone): +55 81 3311-7458<tel:+55%2081%203311-7458> www.estaleiroatlanticosul.com.br<http://www.estaleiroatlanticosul.com.br/> Ilha de Tatuoca, s/n - Complexo Portuário de Suape Ipojuca-PE, Brasil, CEP (Zip Code) 55594-900<tel:55594-900> EAS Confidencial: 0800 721 5970<tel:0800%20721%205970> www.easconfidencial.com.br<http://www.easconfidencial.com.br/> Email enviado pelo celular Email sent by phone A 23 de fevereiro de 2019 12:33:40, Neil Dencklau <denck007@umn.edu> escreveu: You are probably going to have to do something like "max(0,S1)". This will get principle stress 1 at each node and clip it to always be greater or equal to 0. If you want to view the actual nodal values make sure you select "unaveraged" instead of "averaged" which is the default. Something must be set at every node so it is not possible to just not display negative values. If you want to clean up the display a little you could use capped iso. Neil Dencklau University of Minnesota On Sat, Feb 23, 2019, 2:29 AM "라쉬" <rashi@koreatech.ac.kr> wrote: Dear XAnsys members, I need to calculate "factor of safety" for a brittle material using "elemental" max. principal stress. Since the default "factor of safety" is based on "nodal" stress. I'm planning to use "user defined results". But I only need to extract the positive max. principal stress neglecting any negative values. How can I do it? I'm using ANSYS Mechanical workbench. Thank you. BR, Rashiga Research Assistant Korea University of Technology and Education South Korea _______________________________________________ Xansys-temp mailing list Xansys-temp@xansystest.info http://xansystest.info/mailman/listinfo/xansys-temp_xansystest.info If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list _______________________________________________ Xansys-temp mailing list Xansys-temp@xansystest.info http://xansystest.info/mailman/listinfo/xansys-temp_xansystest.info If you are receiving too many emails from XANSYS please consider changing account settings to Digest mode which will send a single email per day. Please send administrative requests such as deletion from XANSYS to xansys-mod@tynecomp.co.uk and not to the list

> On Feb 23, 2019, at 9:32 AM, Neil Dencklau <denck007@umn.edu> wrote: > >> I need to calculate "factor of safety" for a brittle material using >> "elemental" max. principal stress. Since the default "factor of safety" is >> based on "nodal" stress. I'm planning to use "user defined results". >> But I only need to extract the positive max. principal stress neglecting >> any negative values. >> How can I do it? I'm using ANSYS Mechanical workbench. If you're looking just to make a plot you can do it real easy by setting the contour values to range from 0 to whatever your max value is. No need to write any code to exclude anything. As a practical matter you're wasting your time with this whole exercise of excluding compressive stresses. Anyone with any sense will understand that there are areas of compressive stress that are to be ignored. Your display will look a lot more professional if you present all the data. But that's your call. Christopher Wright P.E. |"They couldn't hit an elephant at chrisw@skypoint.com | this distance" (last words of Gen. .......................................| John Sedgwick, Spotsylvania 1864) http://www.skypoint.com/members/chrisw/