Answer to Question #256119 in Mechanical Engineering for Hugh

Question

QUESTION 2 [14 Marks]

In a metal workshop a technician is tasked with making calculations on metal strength

properties. The technician is given two rectangular plates, one of steel and the other of brass

each 40 mm wide and 10 mm deep and these are placed together to form a beam 40 mm wide

and 20 mm deep, on two supports 1 m apart, the brass plate being on top of the steel plate. You

are required to calculate the maximum load which can be applied at the centre of the beam

given that the plates are either

(a) Separate and bend independently,

[6]

(b) Firmly secured throughout their length.

[8]

Given: The maximum allowable stress in steel= 112.5 N/mm2

and in brass = 75 N/mm2

.

Take Es = 2 X 105 N/mm2

and Eb = 8 X 104 N/mm2.

Answer 1

maximum load F = maximum allowable stress in steel $\times$ Area

$F =112.5 \times(40\times10) =45000N= 45kN$