56. A concentrated mass M is allowed to fall through a height of 12 mm to strike a simply supported steel joist at mid-s
Posted: Fri Mar 04, 2022 10:09 am
56. A concentrated mass M is allowed to fall through a height of 12 mm to strike a simply supported steel joist at mid-span. The joist has a span of 3.6 m and for the cross-section, the depth is 240 mm and the second moment of area, Ixx 80 x 10-8 m. Calculate the maximum value of M if the momentary bending stress in the joist must not exceed 120 MN/mº. Neglect the loss of energy at impact. E = 200 GN/mº. (U. Lond.) (Ans.: 1.406 Mg)