Question

The part shown in the figure has a circular cross-section of 0.04 m diameter. It is made of a steel with a yield strength of 343 MPa and an ultimate strength of 410 MPa, and is subjected to a force, F, of 2500 N.

Fぐ

1. Locate the most critical point. (2 points)

2. Plot the three-dimensional stress element for that point. (2 points)

3. Calculate the values of stresses. (6 points)

Answer 1

F 2500N 0 2m d 0 04m 0 As we move away from ends of part, the forceF Starts becoming eccentric and starts induing bending moment Hence effects oF -force F D Normal tensile stress throught the bar cross - section 2) Bending stress due to its ecentricity the eccentricity is maximum, and hence the b At section mom ent will be maximum Bendine moment at section ①O= Fe = 2500x02 500 N-m (sasging in nature) Sagging bending mo ment induces contraction in fibres above NA and expansion or tensfon in fibres belono N'A So at 'g p tensile stress due to F and bending stress (maximum at extreme fibres) at g adds on and makes point B" most critical int· the like natureof direcr At A" compretsive bending strex and diredt tensile stress. try to coun teracr and hence net stress magnitude decreases at A 3 D-Stress elerment at & ơaxial tobending axial +obend In Stress at 2 A THA xo-02 500 g|ら66 908.33 Nİmp ơx=2500 . x 0044 74x0 042 76 - 31-566 MPa (Ans)