Altair RISE

A program to recognize and reward our most engaged community members

Nominate Yourself Now!

Frequency response analysis

Hello sir

I am doing frequency response analysis in optistruct. I have put unit load using DAREA CARD ,I want graph of acceleration vs frequency graph. But it give graph of Displacement vs frequency. Plz help me how can I plot acceleration vs frequency and how can I find phase difference.

I am waiting for your quick reply.

Thanks

Noor Alam

Find more posts tagged with

English

OptiStruct

Accepted answers

All comments

Altair Forum User

Hi @NOOR ALAM ANSARI

Did you request for acceleration from global output request?

NoorAlam_08

Hi @NOOR ALAM ANSARI

Did you request for acceleration from global output request?

Hello prakash

i have request the acceleration in Global output request but it showing only displacement .

plz let me know how can i get the output graph of acceleration vs frequency graph.

i am waiting for ur quick reply.

Thanks

Rahul Rajan_21763

Could you share .fem file and .h3d file to check same at our end?

You can also download recently released free ebook on OptiStruct Dynamic Analysis using below link.

https://altairuniversity.com/free-ebook-learn-dynamic-analysis-with-altair-optistruct/

NoorAlam_08

Could you share .fem file and .h3d file to check same at our end?

You can also download recently released free ebook on OptiStruct Dynamic Analysis using below link.

https://altairuniversity.com/free-ebook-learn-dynamic-analysis-with-altair-optistruct/

Hello Rahul

can i share same process on a flat plate which i have done because its confidential .plz help me out.

how can i find acceleration vs frequency graph.

thanks

Rahul Rajan_21763

As mentioned above just request ACCELERATION in the Global output request card.

<?xml version="1.0" encoding="UTF-8"?>

NoorAlam_08

As mentioned above just request ACCELERATION in the Global output request card.

<?xml version="1.0" encoding="UTF-8"?>

Thanks RahuL R

Now i have done it on a plate but it not showing acceleration vs frequency graph it showing zero acceleration on cotour. it gives displacement vs frequency graph. I have put a unit load on z direction using DAREA card.

i am sending the attached file. plz help me out .

THANKS

Unable to find an attachment - read this blog

Rahul Rajan_21763

I checked your file.you applied load on y direction.See below screenshot.

<?xml version="1.0" encoding="UTF-8"?>

Nachiket Kadu_22143

Thanks RahuL R

Now i have done it on a plate but it not showing acceleration vs frequency graph it showing zero acceleration on cotour. it gives displacement vs frequency graph. I have put a unit load on z direction using DAREA card.

i am sending the attached file. plz help me out .

THANKS

@NOOR ALAM ANSARI You didnt refer node set for the output to generated?? and also you are trying to write the graph in h3d. Either keep it default or HG.

Unable to find an attachment - read this blog

NoorAlam_08

Hi Rahul R

yeah its y direction by mistake i wrote z direction sorry.thanks for checking my model.

but plz help how can i find acceleration vs frequency graph in hypergraph.

if possible plz share with me the correct model.

Thanks

NOOR ALAM

NoorAlam_08

Hi Rahul R

yeah its y direction by mistake i wrote z direction sorry.thanks for checking my model.

but plz help how can i find acceleration vs frequency graph in hypergraph. I have done it again but i have not get the result which i need.so plz help me out how can i find.

if possible plz share with me the correct model.

i am waiting for your quick reply.

THANKS

NOOR ALAM

NoorAlam_08

Hi Nachiket

i have make it HG in Global output request.

but i am geting same result

Nachiket Kadu_22143

Hi Nachiket

i have make it HG in Global output request.

but i am geting same result

did u refer node set? For option you are using ALL, instead give SID and refer that node set. You will get frf for acceleration.

Rahul Rajan_21763

Please see attached video.You can directly open h3d file in Hypergraph.

Unable to find an attachment - read this blog

NoorAlam_08

Got it.

Thank you very much

Mr. Rahul R & Mr. Nachiket kadu to helping me out.