In: Civil Engineering
A hydraulic punching machine is used to make holes in a plate
using two steel punches having
different diameter. By applying a compressive stress of 37 x103
kN/m2 using a punch of diameter
50 mm, the maximum shear stress developed in the plate was found to
be 290 N/mm2. Suggest the
value for thickness for the plate suitable for this loading
condition.
What will be the change in the shear stress when a compressive
force of 85 kN is applied on the
plate of same thickness using another punch having diameter 12%
more than the first one? Check
which one of the steel punches used is safe against shear, if the
permissible safe shear stress on
the plate based on the design conditions is limited to 300 N/mm2.
Based on the results, discuss
how the thickness of the plate and the diameter of the punch can be
modified to withstand the safe
shear stress.