Question

The spring mechanism is used as a shock absorber for a load applied to the drawbar AB. (Figure 1) Each spring is originally unstretched and the drawbar slides along the smooth guide posts CG and EF. The ends of all springs are attached to their respective members. 

Part A 

Determine the force in spring H when the P = 60 kN force is applied. 

Part B 

Determine the force in spring AG (and, by symmetry, BF) when the P = 60 kN force is applied. 

Part C

What is the required diameter of the shank of bolts CG and EF if the allowable stress for the bolts is σ_allow =190MPa ?

Answer 1

Solution Let's draw simplizied dieglam of the systom ta stiga nesses (kayo 80 A B 60 MALE ( 2 ) 60 same P- 60 kN > All springs are in patelle connection as the dezamation in each of three is under application of food of 60 kN. k tk tka (in parald + kap con com netion (kN/m 80 +60 +60 key 200 kN/m Dezsimation in each of the s sporings 8 = 8 Sz - Sz P 60 200 S 0.3 m ky

A) Farce i spring H FA - KA SH ki si IFH 80 (0:3) 24 kN Extension 201ce B Tonsile ce Farces in sparings AG and BF KBE 60 kN/m the forces in sporings AG and BF are smce KAG same, P = FH+ FAG+ FBF → P. и + 2 Где 60 24 + 2 2 The २ 36 FAG - 18 kN gol For = Faq 18 kN compotessive garce

Diameter of shank & bolts CG and EF; FBD S f - ၁၈၁၅၁ sporings AG AG and BF 18 kN 18 kN A B G f 18 kN + 7 16 kN and EF FBDS of members C G Rc Ace с sto f 18 KN 18 KN Rez 18 KN CG sty RE = 18 kW Both members are mi tension. Fy 7 EF 3 4x18x1o® (MP ben B A d² Td2 d (mm

. 3 72x103 Ad 2 BF CG 981 Saze design 5 < Jallow < 190 72x103 īdz de > 3 72X10 190T → d² 120.623 all mm) Required minimum diametot belts