damping and inertia

[liu xing]

hello,everyone

I have one question about structural simulation. I don't know which one i should choose for my structural simulation , static or dynamics ?

I know when we consider the damping and inertia, we should choose dynamics. But so sorry that i couldn't figure out wether should i consider the damping and inertia during one case.

hope to get your view. thank you so much

 

[Retrograde]

Generally it depends on the how fast the load varies. If the load varies "relativity" quickly compared to the natural frequency of the structure then dynamic analysis is warranted.

 

[liu xing]

can you show me the detail of it ?how compare each other? how to calculate it? because i don't know at all.

 

[WARose]

For a single, suddenly applied load......you can generally handle that with a impact factor in a static analysis. But for a repetitive unbalanced force (like say from a piece of machinery like a compressor or a fan) a dynamic analysis may be in order.

 

[liu xing]

@WARose
hello,thank you so much~
this is first time I hear that can use impact factor in static analysis. Because I think that static analysis only include the static load. But I can't find this setting in ANSYS WORKBENCH.

 

[GregLocock]

Don't use that impact force approximation until you understand exactly where it comes from. It is one of the most quoted and least reliable rules of thumb I can think of. (Basically its just SHM)

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[liu xing]

@GregLocock
hello, in fact , I conldn't get your point exactly.
Yes , I am new here. thank you for information~