Problem #0053 Mechanics Sub-menu Problem #0055 Chapters Chapters

54.

Problem 14.45 (RHK)

We have to calculate the force F needed to punch a 1.46 cm diameter hole in a steel plate 1.27 cm thick. The ultimate shear strength of steel is 345 MN/m2.

Solution:             Click For PDF Version

When shearing stress is applied the force vector lies in the plane of the area rather than at right angles to it. For this problem the relevant surface is the outer surface of the cylinder that is pushed out of the metal plate. Its area A is

, d is the diameter of the cylindrical hole and w is its width.

Shearing stress.

As the ultimate shear strength of steel is , the force F required for punching the hole in the steel plate will be