Custom Search
|
|
|
||
 (7) Compute the natural period of vibration for the 1-ft width
of panel:
m = w/g
= (4.8 x 106)/32.2
= 0.15 x 106 lb-ms2/ft.
TN = 2[pi](0.74 x 0.15 x 106/46,380.3)1/2
= 9.68 ms
(8) Calculate B/ru and T/TN:
B=p
= 4.3 x 144
= 619.2 lb/ft2
B/ru = 619.2/1,111.8
= 0.56
T/TN = 40/9.68
= 4.13
Entering Figure 6-7 of NAVFAC P-397 with these ratios:
[mu] = 1.10 < 3.0
O.K.
(9) Check maximum deflection and rotation.
XE = ru/KE
= 1,111.8/46,380.3
= 0.024 ft
Xm = [mu]XE
= 1.10 x 0.024
= .026 ft
tan [theta] = Xm/(L/2)
= 0.026/2.25
= 0.012
[theta] = 0.69 < 2.0
O.K.
(10) Check resistance in rebound:
From Figure 41, required r -/ru = 0.55
r - = 0.55 x 111.8
= 611.5lb/ft2 (neglect small dead load)
Available maximum elastic resistance in rebound:
Calculate r - = 4(2 x 2167 + 1730)/(4.5)2
= 1197.8lb/ft2 > 611.5
2.08-180
|
 
|
|
|
||
