4. Dynamic modeling of the connecting rod

The aim of this paragraph is to explain the dynamic behavior of the connecting rod, an approach that is valid whatever the type of combustion engine considered, 3-cylinder, 4-cylinder, gasoline or diesel...

When establishing the equations relating to acyclism, in particular the relationships involving the inertial torques of the mobile coupling elements, the concept of the connecting rod's reciprocating and rotating masses was used to estimate the latter's contribution to inertial effects. This concept involves replacing the connecting rod with an alternating mass attached to the piston and a rotating mass attached to the crank pin, these two masses being separated by a fixed distance: the connecting rod center distance. This simplification makes it very easy to estimate forces, and the concept of a connecting rod replaced by two masses is particularly well suited...