Question

A cantilever spring made of SAE 4340 heat-treated steel is 50 mm thick. As shown in the figure, the depth of the rectangular cross sec- tion is reduced from 80 mm to 40 mm using fillets at the transition A factor of safety of 2.5 with respect to fracture is specified for the spring. Determine the maximum safe moment M for the spring if: M 40 mm 80 mm (a) the fillet radius r is 4 mm (b) the fillet radius r is 12 mm Radius r

Answer 1

Thikness of membon Samm Seofety Fs heat troted steel of tnice ha folasng dyevy 2-S Factor of 2 SAE 4340 yeild SOmm Marm sbergin 4om wwoB O. 40 2.S 2 .S 0.25 O.IS 2 Focm atove we Can Curve Say tat

Callaa Allocuable stess FOs 880 N/mm 3S2 Collo 2.S -Omax allaw. SOm 'may 352 40 1ss.26m A ma 266666.G mm NA (2 ma 18S. 26x 266666,67 20 2470133. 3N-mm 2.47 kN -m M 91 O.3 40 2-5 T 2 O.3 1 O.2 o.25 o.15 0.oS 3

kt.45 alo 352m 2 Oallo omal 3S2 242.76 Nma2 1F5 INA 4 ww t9"999998 Nomal man M 2426x 266666.6a 3236800 N-mm l-N89 ET 'E -