co-relation between practical and virtual conditions

Altair Forum User

Hi,

In Radioss solver completed a test of run time 0.3 second in 15 hours.

In practical condition we have to run the same test for 3 hrs.

How could we obtain the same output of practical condition in virtual?

Is it essential to run the analysis for 3 hrs(180 min*60 sec=10800 seconds)?

 

 

 

 

Altair Forum User

Hi Tushar, 

 

depends on the test.

 

Say for example you want to do a drop test of a ball from 10mts height. For this case you dont have to drop the ball from 10mts in virtual. 

 

You can calculate the velocity from a particular height (like 0.01mts) and run from there.

Altair Forum User

Thank you.

Altair Forum User

Hi Prakash,
I have  similar query in case of vibration of shaker table.

Vibration Analysis is running successfully and behavior is also correct.

Now according to practical conditions we run the vibration test for 2 to 3 hrs, wherein frequency of shaker table is 3Hz and amplitude is 1 inch(25 mm).

According 3Hz frequency, we calculated time for 1 cycle=1/3 sec which is 0.333 sec.

For a complete run of one cycle, analysis is taking about 12-15 hrs.
But as in physical condition test run is for 2hrs, for me the number of cycles becomes 2400 cycles. This means my total run will be for approx. 28800hrs.
Kindly suggest how we can reduce the total test run time, at the same time co-relate practical and virtual test runs.

Thank-You
 

Altair Forum User

Hi Sachin,

 

If you are taking about converting time signals to Freuqncy, this has be done through FFT (Fourier transformation)

Altair Forum User

Hi,

Will you suggest me to how to perform this analysis through FFT? 

Or Any other suggestion?

Altair Forum User

Hi,

Anybody suggest the same?

Rahul Rajan_21763

To carryout frequency response analysis refer optistruct tutorials.For conversion refer below post.