Calculation of stresses in the finite elements of deformed constructions

Under study is the problem of deformation of a curved rod in the form of a circular arc. Using the previously developed version of the functions of the form of a curvilinear finite element, we construct a solution that differs slightly from the exact one with respect to displacements even for few elements; however, the bending moment is calculated with a greater error. As a result of the direct integration of the equations of the problem for this rod, there are constructed some modified functions of the form from which an “exact” stiffness matrix is calculated. These functions yield the construction of the functions of the form with a parameter and the reason is clarified why the calculation of the force factors by differentiation of such functions fails to be exact. Also, we demonstrate a possible nonuniqueness of the obtained results for the stresses under the same errors in the stiffness matrix.