h08_solution.pdf - ME 360 H08 Name 1 For the tension spring tested in class compute spring constant k and tensile load Fy that would cause the spring to

h08_solution.pdf - ME 360 H08 Name 1 For the tension spring...

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ME 360 – H08 Name _________________________ 1) For the tension spring tested in class, compute spring constant k and tensile load F y that would cause the spring to yield in the body of the spring (not the hook ends). Is this a standard wire diameter? d _____________ OD_____________ N a _____________ k _____________ F y _____________ standard d ? YES NO circle one D = OD – d = 0.430 in C = D / d = 6.8254 G = 11.7 x 10 6 psi Table A-1 Norton k = ( ) ( ) ( ) = 2 6 3 4 a 3 4 in lbf 10 x 7 . 11 75 . 18 in 430 . 0 8 in 063 . 0 N D 8 G d = 15.45 lbf/in assume A228 music wire S ut = A d b = 289.4 ksi A = 184649 psi b = -0.1625 Table 14-4 Norton S ys = 0.45 S ut = 130.2 ksi Table 14-8 Norton use Eq. 14.9b C 615 . 0 4 C 4 1 C 4 K W + = = 1.2189 ys 3 W MAX S d D F 8 K < π = τ Eq 14.9b Norton F y < ( ) ( )( ) π = π 2 3 3 W ys 3 in lbf 10 x 2 . 130 in 430 . 0 2189 . 1 8 in 063 . 0 D K 8 S d = 24.39 lbf 0.063 0.493 in 18.75 15.45 lbf/in 24.39 lbf
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