Question

what is the force required to punch the hold if a hold of 30mm diameter is punched in a plate of 5mm thickness and shear stress of the plated material is 400kg/mm ? *​

Answer 1

Answer:The actual shear stress in the material is  τ=FA  

So the material fails when:

τ≥Su  

or

FA≥Su  

or

F≥Su(A)  

The minimum force required will be:

F=(Su)(πD)t  

F=(350MPa)(π20mm)25mm  

F=549800N  

Note that if we use units of [MPa] and [mm], then the answer will be in [N].

Since  1MPa=106Nm2=106(N106mm2)=Nmm2  

Explanation: