Question

2.) Design a helical extension spring with standard hooks to handle a dynamic load that varies from 300 lb to 500 lb over 2 in working deflection. Use chrome-vanadium wire. The forcing frequency is 1000 rpm. Infinite life is desired. Minimize the package size. Choose safety factor for fatigue 1.28. You make the following design choices; spring index C 5.5 and Wire endurance limit Sew-45 ksi.

Answer 1

ntven ew forke a 2 mtn 200b loob radt mean min for 30ob mtn

2 tnding mean Coll wre diamcter d = 0.406 2333 Fundt hita Gh.strers (%) ubstidute 5.5 ㄈ-4, 23 (t66. 34) +131,5 (30.29-1862E 5 +28040 03. 14 549D. 375828 s 2864 3 413a 35 194

Findt าธุ 2 38404 -4%,96 4225 q 2-1884 5 + 3 y404. 4-26212-345 4 381

d durect aess of sheas 5,5+o.5 Finding uhl Fatr Ku Substtute C5.5 224 5.5 5.5 t21、半.10.98 q9 243

Calcu late shear stress ) り2, 2, 2 3 3 to 2#6 81's p 14,05 2 a 233

3.4.120 2 Findin A Hernahag shear tress Ta て d D2.233 dr 406 (0, 406)3 ㅠ d 2to 24

Ad 0.14 53 culate tors to na eld strengthS Sub stitute t 4St

132, 2 Ks ex orslo Sub ati tute e 4-5 Kst us133 33 ksi ty Sur = 26,2 ks、

to K 35343 245,4 14 40.98 Ps o66 415.5) 5,5-

23 (4.5) 21-5.5- 49