Design Example 3. Calculate the Natural Frequency
Design Example 3. Calculate the Natural Frequency
WDL = Wslab + W beam = (0.041 ksf)(41 ft)(10 ft) + (0.044 k/ft)(41 ft) = 18.6 k
WLL = (10%)(0.080)(41 ft)(10 ft) = 3.3 k (assumed 10% of live load active)
WTOTAL = 18.6 + 3.3 = 21.9 k
= 5.3 Hz < 10.0 Hz ===> Continue the analysis
t
3
p (386.4 in/sec/sec)(29000 ksi (2648 in )
2 (21.9 k)(41 ft x 12)
f = (p/2) g E I / W L
f =
4
3