Spectral Value vs Frequency Graph

[Settler]

Hello,

I would like to ask you if I can, and if yes how, obtain a response spectrum for my structure, for a given direction of ground motion (earthquake)with an unknown frequency.

I would like the result to be a graph or a table with frequency values vs spectral or acceleration values.

Thanks in advance.

 

[speedmethal]

by harmonic response analysis.

 

[Settler]

maybe you have any link of any tutorial?

Thanks a lot anyway! I will search this way...

 

[speedmethal]

for all I know, response spectrum can only be obtained introducing harmonics loads by Harmonic Response.
If you do a Transient Structural you can obtain graphs with deformation, velocity or aceleration vs time. That table within data can be exported to .xls and if you perform Fourier Tranform above that data you will obtain amplitude(deformation, velocity or aceleration)vs frecuency.

Do you use Mathematica? i performed Fourier Transform with Mathematica and i could send it you.

i hope have been helpful

 

[speedmethal]

I use the tutorial of Ansys. I've got a tutorial of Ansys Workbench 11. if you want i send it you.

One question. Have you introduced real accelerogram data? i need enter accelerogram data (acceleration vs time) on the basis of my model, but i don't know how do it?

 

[Settler]

I think this can be done with aDYNA a programm that collaborates with ANSYS. (enter accelerogramm data)

All I need is how the structure will respond at different frequenses of ground motion.

If anyone knows please help

 

[speedmethal]

Ansys Tutorial says:"Transient Structural (ANSYS) Analysis

Introduction
You can perform a transient structural (ANSYS) analysis (also called time-history analysis) in the Mechanical application using the transient structural analysis that specifically uses the ANSYS Mechanical solver. This type of analysis is used to determine the dynamic response of a structure under the action of any general time-dependent loads. You can use it to determine the time-varying displacements, strains, stresses, and forces in a structure as it responds to any transient loads. The time scale of the loading is such that the inertia or damping effects are considered to be important. If the inertia and damping effects are not important, you might be able to use a static analysis instead."

I've tried to introduce the acceleration on the basis, but this can not be done. However, introduce the displacement is o.k. (by numerical integration of the accelerogram). But I get a new problem, a error is shown:

Number of results on results file exceeds maximum of 1000. Maximum may be increased with /CONFIG command.

I introduce a command with the line /config,nres,15000 but ansys workbench seems not understand it.
How can i change it?

i don't know if this analysis is the best form to obtain the response of the structure excited by earthquake.

 

[krs2ball]

Hello,

For all I know, you can only introduce accelerogram/time from ANSYS 11 and newer versions.

I do have a problem. I want to import my accelerogram (known earthquake) and it forces me to create a XML library.
I don't know how to do this, has anyone come across this problem?

Thanks in advanse