Question

Question 2 The steel cantilever beam shown here is subjected to a fluctuating transverse force, P, The part is solid and cylindrical with a diameter of 30 mm The bar material is machined and made of AISI ASTM Class 40 Steel machine finish. It will be used at room temperature. A reliability of 95% is desired for the part. a. Find the Design Endurance Limit (S.) b. Find the Endurance Strength at 100,000

Answer 1

The properties of class 40 steel is taken from design data hand book

Giren Information Steel cambleveo beam IST ASTM class40 de Gomm, reliabilinge 95% THE 590MPa Gu=440Mpa - Yield strength = Oltimate Strength Ce=0.6180=29408 MPa endurance limit for polighed steel specimen (a) Design Endurance Limit [se] @ Surface correction factories) For Machined surface lg = 0.85. i) size correction factor. (esz) Fer diameter 7.5<dssomm est: 0:85 Load Correction factor ceat For reversed loced (bending 7 ex= 1 (rv) Betalingity factor = .95=60 Design endurance birit Se=estgestelde = .95 (0.85)485)x1x 2948 202.34 Mpa (6) Endurance strength at 100,000. Assuming factor of Sately=2=1 D a ten (soderberg criteria] 2A Gas Prax - Pmin 100,000 $10000 2A Pmax = 100000 Pmin= 100000 , Time fetaxt Bacing 200000 0 -ZA 40000 =141.HTMPO

Im = Praax-Prino Is be 121.4 Fe5282.94 Mpa