Question

Determine the largest axial load P that can be safely supported by a flat steel bar consisting of two portions, both 10 mm thick and respectively, 40 and 60 mm wide, connected by fillets of radius r=8 mm. Assume the maximum allowable normal stress is 165 MPa. D/d = 2 13 0.3 2r/D 0.4 0.5 0.6 0 0.1 0.2 a) Flat bars with holes 0.7 O 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 rid (b) Flat bars with fillets

Answer 1

. 40 mm We first compute the ratios 8 mm = 0.20 D - Gomm - 150 V = 40mm Using the curve in fig.b corresponding to Old = 1.50, we find that the value of the Stress- concentration factor corresponding to Yld = 0.20 is will K= 1.82 carrying this value into following equation, Gave = 8 max Cave = omax But omax cannot exceed the allowable Stress gali = 165 MPa : Substituting this value for Gmax we find that the average stress in the narrower cd = 40mm) of portion the bar should not exceed the value Gave' : * 165 MPa : 90.7 MPa 1.82 = 70 tla Recalling that have = Pla we have, Eate= P= As Gave '20 = (40mm) (comm) (90.7 MPa ). = 36-3x10°N IP = 36:3 KN I Answer)