What is Dynamic Analysis?
What is Dynamic Analysis?
(OP)
Hello everyone,
1)Can any one tell me exactly the definition of Dynamic Anslysis?
2) I have modelled a bearing pedestal. I have choosed Shell63 as my element. I have applied a mass of 1000 kg on top of the pedestal. When i found the frequencies of the pedestal,the values are in decimal i.e., 1).35Hz 2) .55Hz etc. When ever i am doing a modal analysis i am getting frequencies in fraction( very low values) when i am choosing shell63 or solid 72. When the mass is low, the values are some what higher. Can any explain the reason for this?
1)Can any one tell me exactly the definition of Dynamic Anslysis?
2) I have modelled a bearing pedestal. I have choosed Shell63 as my element. I have applied a mass of 1000 kg on top of the pedestal. When i found the frequencies of the pedestal,the values are in decimal i.e., 1).35Hz 2) .55Hz etc. When ever i am doing a modal analysis i am getting frequencies in fraction( very low values) when i am choosing shell63 or solid 72. When the mass is low, the values are some what higher. Can any explain the reason for this?





RE: What is Dynamic Analysis?
m x''+c x' + k x = F
For question 2.....Think of a SDOF system where
omega = sqrt (K/M)....
As M gets smaller omega (and the frequency) get bigger...
Ed.R.
RE: What is Dynamic Analysis?
RE: What is Dynamic Analysis?
Manigreat,
I am guessing that you might not have constrained the model. When performing a modal analysis you and you don't constrain the model, the first few (six, depending on the which constraints were omitted) modes calculated will have effectively zero values for frequency. Imagine the model moves off in one direction and never comes back, resulting in a zero frequency. You may need to constrain your model or tell the program to expect the unconstrained modes. The higher modes may show correct values depending on how many you asked for. See more theory and information regarding vibration analysis at http://feaservices.com