Page 140 - Thomson, William Tyrrell-Theory of Vibration with Applications-Taylor _ Francis (2010)

Chap. 4 Problems 127

given by the equation

+ {^nhŸ V^l + {^nUŸ
Plot this result.
4-25 In Prob. 4-24, if i > ij, show that the solution is
1

ino>„r + — —icosw„(/ - r,) - cosoj^rl
" 0 ) ^ t ^ L /7V 1/ n J
4-26 Determine the time response for Prob. 4-10 using numerical integration.
4-27 Determine the time response for Prob. 4-20 using numerical integration.
4-28 Figure P4-28 shows the response spectra for the undamped spring-mass system under
two different base-velocity excitations. Solve the problem for the base-velocity excita­
tion of y(t) = and verify a few of the points on the spectra.

4-29 If the driver of Example 4.3-3 is sitting on a cushion of stiffness A = 51 Ib/in., what
:
acceleration would be experienced assuming the same drop distance?
4-30 During ejection from a military airplane, the pilot’s acceleration must not exceed 16 g
if injury is to be avoided (see Ref. [5]). Assuming the ejection pulse to be triangular.