Flexural rigidity

About: Flexural rigidity is a research topic. Over the lifetime, 3829 publications have been published within this topic receiving 56780 citations.

Flexural Stiffness Control of Multilayered Beams

Abstract: This paper focuses on the ability to introduce change in the flexural bending stiffness of a niultilayered beam. The multilayered beam comprises a base layer with polymer layers on the upper and lower surfaces and stiff cover layers. The flexural stiffness can be reduced by effecting a reduction in the shear modulus of the polymer layers by heating through glass transition. Stiffer polymer layers strongly couple the cover layers to the base beam and the entire multilayered beam bends more as an integral unit On heating, a reduction in the shear modulus of the polymer layer results in its undergoing shear deformation as the base beam undergoes flexural bending and results in the cover layers decoupling from the base beam. This reduces the overall flexural bending stiffness. A finite element analysis is developed for the multilayered beam, and after experimentally verifying its ability to predict change in flexural bending deflection under load with a change in the polymer-layer shear modulus, it is used to conduct parametric studies. The results of the parametric studies provide broad insights into how the achievable change in flexural bending stiffness with a change in the polymer-layer modulus varies with design parameters such as the modulus and thickness of both the cover layers and the polymer layers. Changes in flexural bending stiffness by a factor of over 70 for a clamped-free beam and by a factor of over 130 for a pinned-pinned beam were observed for certain configuration designs.

Mathematical Model for Vibrations of Non-Uniform Flexural Beams

Abstract: A simplified mathematical model for free vibrations of nonuniform viscoelastic flexural beams is presented The mass intensity, the material damping intensity and the flexural stiffness of the beam are assumed varying as power functions along the beam An analytical solution for the fourth order differential equation of beam vibration under appropriate boundary conditions is obtained by factorization Mode shapes and damped natural frequencies of the beam are obtained for wide range of beam characteristics The model results agree with those found in literature for uniform beams

Nonlinear Equation for Flexural Stiffness of Slender Composite Columns in Major Axis Bending

Abstract: The ACI standard 318-02 permits the use of a moment magnifier approach for the design of slender composite steel-concrete columns. This approach is strongly influenced by the effective flexural stiffness (EI) , which varies due to the nonlinearity of the concrete stress-strain curve and the cracking along the column length among other factors. The EI equations given in the ACI code are approximate when compared to the EI values computed from the axial load-bending moment-curvature relationships. This study was undertaken to determine the influence of a full range of variables on EI used for the design of slender, tied, composite columns in which steel shapes are encased in concrete, and also to examine the existing ACI EI equations. Approximately 12,000 isolated square composite columns, each with a different combination of specified properties of variables, were simulated and used to generate the stiffness data. The columns studied were subjected to short-term ultimate loads and equal and opposite end mo...

Experimental evidence of the electrostatic contribution to the bending rigidity of charged membranes.

Abstract: We address the issue of the origin of the bending rigidity of a charged membrane formed from amphiphilic molecules. Electrostatic effects are investigated by direct measurement of the force necessary to deform a catanionic membrane as function of the ionic strength of the medium by means of an atomic force microscope (AFM). Using continuum mechanical modeling of membrane deformation, we derive the bending rigidity of the catanionic membranes and monitor for the first time its decrease in response to increasing salt concentration.