Page 5 - Mechanics of Structures – Chapter 1

Mechanics of Civil Engineering Structures – Chapter 5

7.3 Shear stresses for Standard Cases

A shear stress, denoted (Greek: tau), is defined as a stress which is applied
parallel or tangential to a face of a material, as opposed to a normal stress which is applied
perpendicularly.

SI symbol: τ SI unit: pascal derivations from other quantities: τ = F / A

is applied to the top of the square while the bottom is held in place. This stress results
in a strain, or deformation, changing the square into a parallelogram

7.3.1 Rectangular Section

Consider a rectangular cross-section of dimension b and d

. .
Shear Stress Equation, τ = =
.
S = Shear force

A = Area of beam above the layer which considered

y = distance of C.G of the area considered from N.A

b = width of section at distance y from N.A

Ixx = Second moment of area of full cross section
about its N.A

NHO JKA PSAS Page 5