What is it about exactly? Provide your email id, if something that I can help, I will email you.

Recently Ansys support some user subroutines in Python language. Refer help manual for exact details.

No, see the definitions @Acoustic documentations Ansys

Creep modulus =constant stress /Creep strain. The strain calculated from above formula is pure creep strain. However, it depends on how the data is measured and reported. I agree, where there is a need, then elastic strain part need to be taken care.

​@@SanthoshKumar-ge9sq Thank you for your fast answer, that makes sense if the definition of the creep modulus is correct. Solvay writes in the Design Guide you have shown: "The creep modulus is derived by dividing the applied stress by the measured strain after exposure to load for a specified time", what would mean that the strain calculated in the video is not pure creep strain. DIN EN ISO 899 defines the creep strain as the change in length at a given time. The english Wikipedia (sorry) says: "creep modulus (constant applied stress divided by total strain at a particular time)". I think there are different definitions all around. I assume Ansys calculates with its creep models always "pure creep strain". Right now I am working on a similar problem. I did not substract the elastic part out of the results of creep test results (from a reputable manufacturer) and now I am 90% sure that this was not correct - but the error is probably relatively small and I am on the safe side because I would have overestimated the total strain.

@@wjojo1 thanks for bringing in clarity here. My assumption was creep modulus was reported based on creep strain only. Ansys deals creep and elastic strain seperately. When creep modulus is calculated from total strain, then elastic strain need to be substracted. When elastic strain in small compared to creep strain over longer duration, the results are conservative as you pointed.

@@SanthoshKumar-ge9sq 👍👍 thanks for the nice discussion! What do you think about, if you want to be absolutely precise, you also must calculate the "true" creep strain and stress because also during the creep test you would have cross section reduction if it is a tensile test. Also in creep tests, the results refer to the initial cross section of the probe. But I think as creep calculations are usually done at relative small loads for the material, also here the difference or error is small (between the "engineering" and the "true" values). What is your opinion on that?

@@wjojo1 you are right. Care need to be taken in terms.of engeneering vs true strain too. All these are possible if you have access to test procedure and raw test data. Data sheets usually don't give this much details. If you want further discussion write to [email protected].

You already have to have a detailed material model to be able to do that, Delany-Bazley, JCA or similar. If so, then you can set up an impedance tube simulation. Basically, an open-closed tube with the absorber attached to the closed (rigid) end. As for boundary conditions; rigid wall bc on cylindrical surface and radiation boundary at inlet. Probe acoustic pressures at distance x1 and x2 away from the absorber. The absorption coefficient can then be calculated by the following expression: alpha = 1 - |R|^2, where R is the reflection coefficient given by: (H12 - e^(jk(x2-x1)) / e^(jk(x2-x1))* e^(2jk(x2-x1) H12 = P(x1)/P(x2) -> (complex fft’s) What you effectively measure is how large the incident wave is relative to the reflected wave.

Yes, through user defined results using expression=NLCREQ

www.ansys.com/en-in/products/structures/ansys-sherlock

@@SanthoshKumar-ge9sq thank you sir

kzbin.info/www/bejne/jIKTepKnd7SngpY

Santhosh Kumar1 year ago !!! Macro to demonstrate EKILL and Restart using * DO Loop !!! Macro by Santhosh M on 16-Oct-2015 !!! Only for above mentioned Demo purpose, may not have physical meaning. !!!! For exact procedure for KEILL and RESTART refer help manual!!!***** PROBLEM DESCRIPTION !!! A plate with a hole is subjectedjected to a tension load !!! When the element stress is 160 MPa or above then the element is killed. !!! Progress of material failure is shown for 5 iterations. FINI /CLEAR /FILNAME,Restart_DoLoop /TITLE, Demo : EKILL + RESTART + DO Loop /PREP7 MP,EX,1,200e3 MP,NUXY,1,0.3ET,1,182,1RECTNG,0,100,0,50 CYL4,50,25,10 ASBA,1,2 TYPE,1 $MAT,1 $REAL,1 ESIZE,2 AMESH,ALLMODMSH,DETACH NSEL,S,LOC,X,40,60 ESLNN,S EPLO EREF,ALL, , ,2,0,1,1 ALLSEL EPLOTNSEL,S,LOC,X,0 D,ALL,ALL ALLSEL/SOLU/OUTPUT,Restart_Doloop_out.outNROPT,FULL !nlgeom,on i=1 TIME,1 NSEL,S,LOC,X,100 F,ALL,FX,100 ALLSE RESCON,DEFINE,LAST,LAST solve /POST1 SET,LAST ETABLE,Sxx,S,X ! Store total equivalent strain in ETABLE ESEL,S,ETAB,Sxx,160 ! Select all elements with Sxx greater than or equal to 190 CM,Kill_loop_1,ELEM CMWRITE,Kill_Loop_1,cm ! Write the component out *do,k,1,5 /SOLU ANTYPE,,REST time,i+1 /INPUT,Kill_Loop_%i%,cm ! Read the component in for Killing CMSEL,S,Kill_Loop_%i% EKILL,ALL ! Kill ALLSE SOLVE i = i+1 ! Move to next iteration now itself /post1 set,last ETABLE,Sxx,S,X ! Store total equivalent strain in ETABLE ESEL,S,ETAB,Sxx,160 ! Select all elements with Sxx greater than or equal to 190 CM,Kill_loop_%i%,ELEM CMWRITE,Kill_Loop_%i%,cm!!! ** This Restart DB file will be called when ANTYPE,,REST command is issued. !!! ** This file actually contains the parameters required for next iteration SAVE,Restart_DoLoop,rdb !!! ********************************************* *enddo/OUTPUT,!!!!! Post processing animation /POST1 ALLSEL EPLOT /EDGE,1,ONSET,1 ETABLE,Sxx,S,X PLETAB,SXX,NOAV !/ui,copy,save,png,graph,color,rverse,portrait*do,s,2,6 T=S-1 SET,S ETABLE,SXX,S,X CMSEL,U,KILL_LOOP_%T% PLETAB,SXX,NOAV !/ui,copy,save,png,graph,color,rverse,portrait *enddo

To input flow resistivity Porous material model has to be used, it can't be input as BC. Refer kzbin.info/www/bejne/jIKTepKnd7SngpY Time 1:22:45

@@SanthoshKumar-ge9sq Thanks so much. Please, how do we estimate the sound absorption coefficient if the flow resistivity such as in the impedance tube experiment simulation? Also, can you show how to plot acoustic SPL along the length of a duct? Thanks