Radoslav Pavazza

On the load distribution of thin-walled beams subjected to bending with respect to the cross-section distortion

The paper deals with the estimation of the load distribution under which distortion of the cross-sections of thin-walled beams subjected to bending cannot occur. It is assumed that beam walls are hinged along their longitudinal edges. Beams with closed and open rectangular cross-sections, with three or two cells, with two or one axis of symmetry are considered. It is shown that the problem can be treated by two equivalent beams, defined by the shear flow zero points of the beam with rigid cross-section. The beam load must be distributed in the plane of beam walls, proportionally to the cross-section moments of inertia of the equivalent beams. Some illustrative examples are given.

An approximate solution for thin rectangular orthotropic/isotropic strips under tension by line loads

Abstract An approximate analytical solution for stresses and displacements in thin rectangular orthotropic or isotropic strips subjected to tension by longitudinal line loads is presented. It is assumed that changes in the transverse direction of the strip middle surface are small, in comparison to the changes in the longitudinal direction, and can be ignored in the shear strain–displacement relation. The solution is given for linearly and uniformly distributed line loads in the longitudinal direction, generally (symmetrically) distributed in the transverse direction. Some simple examples are analyzed, and compared to exact solutions of the plane theory of elasticity and the finite element analysis.

Idealisation of ships with large hatch openings by a thin-walled rod of open section on many elastic supports

The open part of the ships hull with large hatch openings is considered as a prismatic thin-walled rod of open section on many elastic supports subjected to torsion. The stiffness of deck strips and the ships sides in the deck plane is taken into account by elastic supports. Internal forces and displacements of the open part of the hull and deck strips are obtained in an analytical form, using the method of initial parameters. Stresses and displacements can be presented numerically and graphically, in a form suitable for preliminary calculations. A numerical example is given.

An analytic solution for bending of thin-walled laminated composite beams of symmetrical open sections with influence of shear

An approximate analytic solution for bending of thin-walled laminated composite beams of symmetrical open sections with influence of shear is presented. Symmetrically laminated beams that possess membrane orthotropy are considered. The classical Euler–Bernoulli’s and Timoshenko’s bending beam theories are augmented by terms which take into account the shear strain in beam mid-surface as well as the warping of the cross section due to shear. Consequently, the beam is subjected to bending with the influence of shear caused by transverse forces acting in the plane of symmetry and in addition to tension/compression due to shear in the case of cross sections with one axis of symmetry. The beam is subjected only to bending with the influence of shear in the case of transverse forces acting in the planes of symmetry. The expressions for the normal stresses and displacements are presented in the closed analytic form. The factor that depends on the fiber orientation is introduced in order to analyze the material influence on shear. Simply supported and clamped beams subjected to distributed transverse load are investigated. The solutions obtained for open sections are also valid for mono-symmetrical closed sections, taking into account the constraint that loads act in the beam longitudinal plane of symmetry/planes parallel to the longitudinal plane of symmetry. Illustrative examples are provided, and the analytic results show a very good agreement with the results obtained by the finite element analysis utilizing three-dimensional shell elements.