Reading Material (Mechanics of materials, Beer 5th Edition):

Chapter 7 Section 10-13 Objective: Determine the strains and shear strains of a plane strain element. Concepts: Plane Strain Problem: Units: millimeters The cantilever beam shown above is subject to a load P acting at the mid -height of the beam at an angle alpha.

Two strain gages are mounted on the beam at point C (C is also at the mid-height).

Gage A measures the horizontal strain, and gage B measures the normal strain at an angle of 60º ea=125x10-6 . -6 and eb= -375x10 . Knowing that the beam is made of steel (E=200 GPa and ?=1/3), a) Determine the force P and the angle alpha.

b) Determine the principal strains and the orientation of the principal planes at C.

c) Determine the principal stresses at C. Bonus: What is the change in the thickness of the plate?