- #1

hks118

- 19

- 0

## Homework Statement

I am trying to calculate the natural frequency of a steel beam.

## Homework Equations

I=1/12*W*T^3

Volume= T*W*L

M

_{0}=V*ρ

K=(3EI/L^3)

M

_{eff}=(33/140)*M

_{0}+M

_{end}

ωn=√(k/M

_{eff})

## The Attempt at a Solution

This should be a simple plug and chug problem but I can't see what I'm doing wrong.

L=0.4572m

W=0.026035m

T=0.006223m

E= 3*10^6

ρ=7850kg/m^3

M

_{end}=.025kg

I=5.22848E-10

V=7.41E-05 m^3

M

_{0}=5.81E-01

K=0.049237907

M

_{eff}=2.43E-01

ω

_{n}=0.450088787 Hz

But this is way off from my experimental value of around 20Hz. Everything is in kg and m.