If the tearing efficiency of a riveted joints 70%, then the ratio of diameter to the pitch is

Concept:

Tensile Stresses in the main plates might result in tearing of main plate or cover plate across a row of the bolt.

The resistance offered by the plate against tearing is known as tearing strength or tearing value of plate.

Tearing efficiency of joints is given by,

\(\begin{array}{*{20}{c}} {{\eta _t} = \frac{\rm{Tearing\;strength}}{{\rm Strength\;of\;solid\;plate}}}\\ {{\eta _t} = \frac{{\left( {p - d} \right) \times t \times {\sigma _t}}}{{{p} \times t \times {\sigma _t}}} = \frac{{p - d}}{p}} \end{array}\)

\(\therefore \eta = \frac{{p - d}}{p}\)

Calculation:

Given that tearing efficiency = 0.70

 \(\eta = \frac{{p - d}}{p}\)

\(1 - \frac{d}{p} = 0.70 \Rightarrow \frac{d}{p} = 0.30\)