'Periodica Polytechnica Budapest University of Technology and Economics'
Abstract
To describe the equilibrium equations of thin walled open section bars the co-ordinates of centre of shearing are generally used. On the other hand, the equilibrium equations of closed section bars mostly are described by the co-ordinates of centre of gravity.
Modelling simultaneously open and closed section bars in a framework it is expedient to apply the same type of co-ordinates. For this purpose the co-ordinates of centre of gravity are suitable.
For elaboration of equilibrium equations of thin walled bars ill terms of co-ordinates
of centre of gravity the principle of total potential energy is applied
