Abstract:
This thesis presents a method of finite element analysis to determine bucklingload of curved structures in which their undeformed centroidal line can be defined byequations of plane curves expressed in rectangular coordinates. The equations of planecurves used in this study are the circular, parabola, sine, elliptic and catenary curves.In the deformed state, curvatures as well as linear and nonlinear axial strain are expressedin terms of displacements in three dimensional space. Based on the energy principle, onecan write the total potential energy functional which includes the strain energy due tobending in two planes, axial strain energy, and potential energy due to external loads. Finiteelement formulation is used to establish structural stiffness of linear stiffness andnonlinear-s stiffness matrices including linear and quadratic order of displacements. Forbuckling load analysis, nonlinear structural stiffness of quadratic order is neglected andlinear eigenvalue problem is obtained in which eigenvalues and eigenvectors are solvedby using vector iterations method. Numerical examples of various curved structures aregiven and results of buckling loads are compared favourably with those found in literature.This method has advantage over the other finite element methods in such a waythat the discretization was done through the known span length rather than the total curvedarc length, thus data preparation is reduced. Furthermore, the analysis can be done for theother curved structures in which their shapes can be indentified by plane curves expressedin rectangular coordinates.