Bending moment

About: Bending moment is a research topic. Over the lifetime, 14577 publications have been published within this topic receiving 158834 citations. The topic is also known as: bending moment.

On the analysis of cylindrical tubes under flexure: theoretical formulations, experimental data and finite element analyses

Abstract: In the present paper the behaviour of cylindrical elastic tubes under pure bending is discussed. This behaviour is characterised by a smooth global maximum on the load-deflection curve which is due to the well-known von Karman effect, that is to the progressive flattening of the cross section of the tube under bending moment. However, during the loading process another type of failure may also occur before the limit load is reached, that is, at a certain stage the compressed region of the bent tube wrinkles axially and can give origin to a localised instability. Even if these phenomena have been extensively investigated in many classical works, nevertheless the analysis of experimental data shows that there are still some points which seem to be worthy of further considerations, especially from an engineering standpoint and for design purposes. To this aim, a straightforward treatment of the problem is presented which can be employed to give clear reason for several experimental findings by means of plain expressions and with a clear physical meaning. Finally, the results are compared to those obtained by means of a commercially available non-linear finite element code.

The influence on the stress distribution in an adhesive lap joint of bending of the adhering sheets

Abstract: The mathematical analysis of Goland and Reissner of the effect of deformation due to load is examined photoelastically and extended to cover a wider range of suchlike deformations. It is shown that introduction of a bending moment in the sheets opposite to that occurring in the conventional joint can produce a stress distribution on the glue line free from high normal stresses and fairly uniform in shear. A modified design of lap joint to ensure this is proposed.

Piezoelasticity solutions for functionally graded piezoelectric beams

Abstract: This paper considers the plane stress problem of generally anisotropic piezoelectric beams with the coefficients of elastic compliance, piezoelectric and dielectric impermeability being arbitrary functions of the thickness coordinate. Firstly, the partial differential equations for the plane problem of anisotropic functionally graded piezoelectric materials are derived, which the stress function and electric displacement function satisfy. Secondly, the stress and electric displacement functions are assumed in forms of polynomials of the longitudinal coordinate, so that the stress and electric displacement functions can be acquired through successive integrations. The analytical expressions of axial force, bending moment, shear force, displacements, electric displacements and electric potential are then deduced. Thirdly, the stress and electric displacement functions are employed to solve problems of functionally graded piezoelectric plane beams, with the integral constants completely determined from boundary conditions. Two piezoelasticity solutions are thus obtained, for cantilever beams subjected to shear force and point charge applied at the free end, for cantilever beams subjected to uniform load. These solutions can be easily degenerated into the piezoelasticity solutions for homogeneous anisotropic piezoelectric beams. Finally, a numerical example is presented to show the application of the proposed method to a specific case.

Strength of composite sections with foamed and lightweight aggregate concrete

Abstract: Tests on steel hollow tubes of square and circular sections filled with foamed and lightweight aggregate concrete were conducted to investigate the contribution of these concretes to the strength of cross sections of composite members. Eight short column specimens filled with foamed and lightweight aggregate concrete, four specimens each, were tested under axial compression to calculate the squash load. Furthermore, eight simply supported short beams of similar sections, also four specimens for each concrete, were tested in bending to calculate the ultimate moment capacity. Unfilled steel sections of similar specimens were also tested and results were compared to those of filled sections. Theoretical values of squash loads and ultimate moment capacities for the test specimens are also included in this paper. The results of this investigation showed that the foamed concrete contribution to the squash load of composite sections is negligible while its contribution to the bending strength is quite significant. On the other hand, the contribution of lightweight aggregate concrete to the squash load and bending capacity is shown to be considerable.