Question

2 The steel rod BC is attached to the rigid bar AB and to the fixed support at C. Knowing that G= 77GPa, determine. i the diameter, d of rod BC for which the critical load P., of the system is 350N. ii. the critical load P., for the system when d = 12 mm. 375mm Figure 2 500mm

Answer 1

Datos Page no soln Look at torsion spring Bo, क TL GIJ I = GJ d = ko L whethy Gus modulus of zigidity = 77 x 10% pa J = polat moment of Inertia = π C4 2 4 J = X 주(일 Td 4 2 32 L =500 mm = 0.5 m GJ L (77X10 Td4 (0.5) (32) = 1.512 X 10 to do +5 Eme=0 T-Pl sind=0 Ko-Pl sind = 0 e 3 K P = ko e sind Pce = l K-1512 X 1040d4 = Pce l = (350)(0-375) 44 d (350)(0.3752 9.65 x 103 m. 1.512 10 to d = 9.65 mm P

Date: Page not Similarly, (ii) Look at torrion spring BC, to TL GJ L क where, G=778 109 pa. 4 T I CA - I (d4 (0:912 m) 2 J = 2.03575 X 10 me L =500 mm=005 m k = GJ (77X109) (2:03575 X 109) (0.5) S = lsind 0.375 Sind Now P = T +) EMB = 0 -PetT=0 KO =7 Рce, с к S l sind l Po - 677X109) ( 2-03575 X109) (0-5) (0-375) in to Pcz 836 N Ans - Pez = 0.836 KN