固有频率，很简单的：(振动力学4_17题)

yujb025

问题求如图所示的前四阶固有频率。

yujb025

/prep7
mp,ex,,2e11
mp,nuxy,,0.3
mp,dens,,7.8e3
et,1,14
keyopt,1,3,2
r,1,100000
et,2,21
keyopt,2,3,4
r,2,10
n,1,
n,4,0.03
fill
type,1
real,1
e,1,2
egen,3,1,1,4,1
type,2
real,2
e,1
*repeat,4,1
/solu
d,1,uy,0,0,4,1
antype,modal
modopt,lanb,10
mxpand,10
solve
/post1
*get,f1,mode,1,freq
*get,f2,mode,2,freq
*get,f3,mode,3,freq
*get,f4,mode,4,freq
*set,pi,acos(-1)
*set,w1,2*pi*f1
*set,w2,2*pi*f2
*set,w3,2*pi*f3
*set,w4,2*pi*f4
set,list