Question

A hot rolled AISI 1040 shaft made transmits a repeated torque of T=500Nm. The reliability is 50% and the part will be used at room temperature. Find the factor of safety at a section where the diameter is 30mm. Use Goodman criterion T=500Nm 16 mm

Dont go by the 30mm !! USE the 16!!!

Answer 1

-0.712 Obtain the properties of Aisi 1040 shaft Ultimate tensile Strength Sut = 590 MP Yield Stveryth Sy = 490 mpg Endurance limit se* = o.ssut 0.5*590 = 245mpg Calculate the desface factar (ka) & Esco ka=a Sut For hot volled Specimen obtain a,b from table A = 57.7 b=-0.718 : Kas 577 (590) 50.59 Calculate the size factor (ks ) (xoorx Ko=1.24 (d) oito 1.24 (16) For tension, loading factor ke=0.59 For reliability of sol, ko - 1 Calculate the consected endurance limit (se) Se = kako kako se = 0.59*0.921* 0.59x1x(295 mpa) =94.647 mpa -0.107 = 0.921 102 Loading conditions : Repeated torque =) Mean torque Tm= 0+500 = 250 Nm Altenesting torque Ta - 0 F600 - 250N.mm

Clculate the shear stress T = 16T 16x 250x10 3 = 310.849 MPa nd T (16)3 & Von misses Callalate the alternating Stress ba be by using Criteria m = 6a - Foto 1.732X (310.899 ) 538.407 mpa Calculate the factor of safety at Section where d = 16mm n = a + 6m Je Jut 1 = 536.407 538.407 590 94.647 n = 0.1514 no 0.1514 octure for [ no 0.1519)