Question

The simply supported beam is subjected to a uniform distributed load, w of 30 kN/m in the negative y-direction and a point load, P of 15 kN in the negative z-direction. The total length, L of the beam is 6 m. Answer the questions that follow: 'n Eenvoudige opgelegde balk word belas met 'n uniform verspreide belasting van w 30 kN/m in die negatiewe y-rigting en 'n puntlas P = 15 kN in die negatiewe z-rigting. Die totale lengte, L van die balk is 6 m. Beantwoord die vrae wat volg: L/2 P L2 250 mm t 12 mnm 250 mm 10 mmk t- 12 mt 200 mm

Answer 1

Beam is subjected to uniformly distributed load therefore absolute maximum bending moment is present at mid point which is given by the following formula \r\n \ M_max = w.L^2/8 where, w = load acting = 30 KN/M. L = Length or span of the beam = 6 m therefore (M_max)_z-axis = 30 times 6^2/8 = 135 KN.M. Therefore Absolute maximum bending moment about Z - axis is 135 KN.M Beam is subjected to point load of 15 KN at mid point along z direction. Therefore Maximum B M will be acting at mid point about y - axis and is given by the following formula, (M_max)_y = W L/y \r\n \ (M_max)_y = 15 times 6/4 = 22.5 K N m Therefore Maximum absolute BM about y - axis is 22. 5 KNM As the section is symmetrical about y -axis, let us set y-axes at the center of the section But the section is not symmetrical about z - axis Ther