<P> The equation for shear flow in a particular web section of the cross-section of a semi-monocoque structure is: </P> <Dl> <Dd> q = V y S x I x (\ displaystyle q = (\ frac (V_ (y) S_ (x)) (I_ (x)))) </Dd> </Dl> <Dd> q = V y S x I x (\ displaystyle q = (\ frac (V_ (y) S_ (x)) (I_ (x)))) </Dd> <Ul> <Li> q - the shear flow through a particular web section of the cross-section </Li> <Li> V - the shear force perpendicular to the neutral axis x through the entire cross-section </Li> <Li> S - the first moment of area about the neutral axis x for a particular web section of the cross-section </Li> <Li> I - the second moment of area about the neutral axis x for the entire cross-section </Li> </Ul>

First moment of area and second moment of area