Learning Forum

[subin yoon]

We want to run a vibration separator simulation. I want to enter 20*sin(2*3.14*time*20) in displacement, but a question mark keeps appearing. Why? Is it necessary to set modal to the initial value?https://mail.naver.com/read/image/original/?mimeSN=1714978033.291443.28831.22272&offset=2560&size=386152&u=tnqsg02&cid=9f8690769ab127439eddc316c7b855@cweb004.nm.nfra.io&contentType=image/png&filename=1714978027877.png&org=1

[Ashish Khemka]

Hi,

I see no error when I try to put a function with 'time' as variable in a transient structural analysis. Can you please share the snapshot in the message itself?

Regards,

Ashish Khemka

[subin yoon]

I gave modal as the initial condition and inserted displacement in transient mode. However, at this time, it is not possible to use a time function for displacement to excite it. ? sign pops up and I can't proceed.

[subin yoon]

And is it necessary to use modal as the initial condition in transient mode?

[subin yoon]

I want to simulate a situation where the lower part of an object is excited up and down at 400Hz with a displacement of 10mm and a constant pressure is applied to the upper part, and check the difference in displacement change between the lower and upper parts of the object. In transient analysis, the pressure condition at the upper part, I added a sin function as the displacement condition at the bottom, but it did not solve the problem. I wonder what the problem is. I'm also curious how this can be solved.

[Ashish Khemka]

Hi,

Thanks for the update. You can apply displacement as base excitation:

 

Also, please refer to the following Ansys Innovation Course for more details: Mode Superposition Transient Analysis Intro | Ansys Courses

Regards,

Ashish Khemka