Study of the Clamping Conditions in a Connecting-Rod Big End

The connecting rods of most reciprocating engines are required to carry a direct tensile load at some time during the engine cycle. This load is transmitted by the big-end bearing-cap bolts and produces in these members incremental direct and bending stresses, which are dependent on the stiffness of the big-end bearing-cap. The problem is statically indeterminate but can be solved by using the compatibility condition. Expressions for the direct and bending stresses are given, and these are compared with measurements made with electrical resistance strain gauges.