Problem # p021

Flexure stress

A beam is made out of a material with properties given below. Also given are the properties of the beam's cross-section relevant for this problem (N.A. = neutral axis).
    Cross-section :
Central moment of inertia : = 6 cm4
Distance from N.A. to top of beam :a = 1.0 cm
Distance from N.A. to bottom of beam :b = 1.4 cm

Stress limits for material :
Tension : 60 MPa
Compression : 120 MPa

Determine the largest positive bending moment (compression at top) and the largest negative bending moment (tension at top) the beam can be exposed to.