The Coherent Concept of the Lever Arm in a Cross-Section

Abstract

The coherent concept of the lever arm is presented. The new graphical interpretation of the lever arm Z regarding shear flow together with mathematical justifications are provided. The conclusion is, that the lever arm Z is a crucial parameter which connects shear flow and transverse force and it links diagrams of the normal stress and the shear flow for a cross-section and such a representation is not known at literature. There is an analogy between the lever arm regarding the shear flow and the effective width regarding shear-lag effect for normal stress. The background of historical analysis of the issue is presented.