Spacial Beam Analysis using Degree of Rotational Freedom about 3 axes of Rectangular Cartesian Coordinates

Abstract

In finite displacement problems for which to define potential functional is difficult, stiffness equation is generally derived from virtual work equation. In such case infinitesimal rotational angles about three axes of rectangular Cartesian coordinates can be used as degree of rotational freedom. The rotational angles are useful to analyze structures subjected to moments about three axes at one node but may make tangent stiffness matrix not symmetric. In this paper accuracy of the formulation is discussed.