Hello everyone, I'm yuying and I'm curious about the structural damping and hope someone can give me advice.

I'm using the student version of ANSYS WORKBENCH R18.0. And I'm trying to use the modal and transient dynamic analysis to do the same material in different shape of structure to see whether the quality factor will be affected by different structure, I have read some information from the internet and I know how to input the damping value and calculate the value, but I still have some questions from the formula(see the picture below). 


1. what's the physical meaning of alpha damping and beta damping

2. Are the alpha damping and beta damping related to frequency or independently

3. The first term of the formula is the material damping, how to define this term and what's meaning of this term

4. I would like to realize how does the damping work in the ANSYS transient dynamic analysis, will the program setting a model to calculate 

Thank you