Custom Search
|
|
|
||
 Calculate the ultimate resistance, ru, assuming the
angle to be simply supported at both ends:
ru = 8Mp/L2
= 8(271.6)(1,000)/362
= 1,676 lb/in
Calculate the unit elastic stiffness, KE:
KE = 384EI/5L4
= 384(29)(106)(29.37)/5(364)
= 38,945 lb/in2
Determine the equivalent elastic deflection, XE:
XE = ru/KE
= 1,676/38,945
= 0.04304 in
Calculate the effective mass of the element.
Average of elastic and plastic transformation factors;
KLM = (0.79 + 0.66)/2
= 0.725
w = 8.2/12 + (3/8)(16)(490)/1,728
= (0.6833 + 1.701)
= 2.385 lb/in
Effective unit mass of element:
me = 0.725 x 2.385(106)/(32.2 x 12)
= 4,475 lb-msec2/in2
Calculate the natural period of vibration, TN
TN = 2[pi](4,475/38,945)1/2
= 2.13 ms
Determine the response parameters (Fig. 6-7, NAVFAC
P-397)
Peak overpressure,
B = 27.0 x 16
= 432 lb/in
Peak resistance,
ru = 1,676 lb/in
Duration, T = 22.81 ms
Natural period of vibration,
TN = 2.13 msec
2.08-287
|
 
|
|
|
||
