ABSTRACT
Plane elements with circular boundaries are usually studied in polar coordinates that are shown in Figure 3.14 and connected with Cartesian coordinates of the same point by the relations. Governing equations of the plane problem in polar coordinates can be derived from the corresponding equations in Cartesian coordinates with the aid of formulas or as a result of direct analysis of stress-strain state for an element. In polar coordinates, stresses are connected by the equilibrium equation. To construct solution of the biharmonic problem in Cartesian coordinates we must use Laplace transform as alternatives to Mellin transform. It is important that the net result can be transformed to the form.
