Question

The state of stress at a point in 2-D stress system is characterized by direct stresses of 40 MPa compressive and 80 MPa tensile, on mutually perpendicular planes. Shear stress is absent on these planes. The maximum shear stress at this point (along duly identified plane) is

• A. 20 MPa
• B. 40 MPa
• C. 60 MPa
• D. 80 MPa

Answer 1

The correct option is C 60 MPa

As shear stress is absent on these planes, hence normal stresses are principle stresses.
${\sigma }_1=80MPa$

${\sigma }_2=40MPa$

${\tau }_{max}=\left|\frac{{\sigma }_1-{\sigma }_2}{2}\right|=\frac{80-(-40)}{2}$