APPLICATION OF MICROPOLAR ELASTICITY TO THE FINITE ELEMENT CONTINUUM ANALYSIS OF ARTICULATED STRUCTURES

The micropolar theory of elasticity is shown to be capable of accurately modelling the static behavior of a wide class of articulated structures having regular geometries. A technique for determining the material properties of the equivalent continuum which most closely models the behavior of a structural system of discrete members is presented. The micropolar material properties are expressed explicitly in terms of the geometry of the structure, and the material and geometric constants of the constituent discrete members. Finally, the powerful and versatile finite element method is used to analyze the resulting continuum.; Continuum modelling of a discrete structure offers a practical, versatile, and economical alternative to traditional matrix structural analysis techniques. The node points of the elements chosen for the finite element continuum analysis need not coincide with the joints of the actual structure, thus allowing one continuum element to span several discrete elements and enabling substantial reductions in the cost of an analysis. The linear four-node isoparametric element is selected to implement the finite element analysis for the plane micropolar continuum theory. The ability to interface discrete beam elements to the continuum element is incorporated and permits both the correct modelling of free boundary conditions and extremely accurate determination of member forces in critical regions of high strain gradients.; The considerable potential for economy in the analysis of large frame systems, combined with the exceptional accuracy obtained from the continuum model, could one day establish the continuum modelling of discrete structural systems as a prominent trend in structural mechanics.