Flexural rigidity

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

Strength of steel culvert sheets bearing against compacted sand backfill

Abstract: AN INVESTIGATION WAS MADE OF THE ULTIMATE LOAD OF CURVED STEEL SHEETS BEARING AGAINST DENSE SAND BACKFILL. THE LOADING TESTS WERE CARRIED OUT AT A SCALE OF ONE-EIGHT FULL SIZE BY APPLYING AN AXIAL LOAD AT THE END OF PLAIN AND CORRUGATED SHEETS OF VARIOUS THICKNESSES AND RADII OF CURVATURE. DURING THE TESTS MEASUREMENTS WERE MADE OF THE STRAINS, SOIL PRESSURES AND DEFLECTIONS OF THE SHEETS. THE STRESS-DEFORMATION AND STRENGTH CHARACTERISTICS OF THE SAND WERE DETERMINED BY TRIAXIAL COMPRESSION TESTS FROM WHICH REPRESENTATIVE VALUES OF THE COEFFICIENT OF SOIL REACTION /SUBGRADE MODULUS/ WERE CALCULATED. THESE VALUES WERE FOUND TO BE OF THE SAME ORDER AS THE AVERAGE COEFFICIENTS DEDUCED FROM THE LOADING TESTS ON THE SHEETS. THE ANALYSIS SHOWS THAT FOR SMALL VALUES OF THE COEFFICIENT OF SOIL REACTION OR MODULUS OF DEFORMATION OF THE SOIL, AND FOR SMALL VALUES OF THE FLEXURAL RIGIDITY OF THE PLATES, THE SHEETS WOULD FAIL BY BUCKLING, BUT FOR LARGER VALUES OF THESE PARAMETERS THE SHEETS WOULD FAIL BY YIELDING OF THE SECTION. AN ANALYSIS IS ALSO MADE OF THE STRENGTH OF FLEXIBLE CULVERTS UNDER FILLS, FOR WHICH SIMPLE EQUATIONS AND DESIGN CHARTS ARE PRESENTED.

Effect of Bending Rigidity on the Capstan Equation

Abstract: A tensioned fiber or yam in contact with a circular body is analyzed. In the model, a fiber is considered as a linear elastic and inextensible beam. An exact mathematical model is derived and the analytical solution is obtained. Both the beam-body contact and two noncontact regions are analyzed. From the equilibrium equation of force and bending moment, the derived model has three compatible ordinary differential equations, and one algebraic equation from the Euler beam theory with four unknown parameters. From the solutions, the relationship between incoming and outgoing tension is obtained, and we call this the modified capstan equation. The results show the correction connecting the capstan equation and its applications. For example, in a typical case, the capstan equation underestimates the effect of bending rigidity, which renders the only physically possible situation of tension in a real capstan to be the equilibrium of inclined tension. Moreover, the sensitivity of the tension ratio on the variati...

Incorporating Residual Strains in the Flexural Rigidity of RC Members with Varying Degrees of Prestress and Cracking

Abstract: The deformation of reinforced concrete columns and beams is controlled by the variation of the flexural rigidity (EI) both along the member and with applied loads and time Currently, the moment-curvature (M/χ) approach is used to quantify EI Prior to cracking, the M/χ approach provides a pure mechanics based solution for EI; that is, the only components of the model that have to be determined empirically are the material stress-strain relationships However after cracking, the M/χ approach has to be semi-empirical, that is EI has to be determined empirically because the M/χ approach cannot simulate the mechanics of tension-stiffening An alternative approach for quantifying EI using a moment-rotation (M/θ) approach is described in this paper It is shown that the M/θ approach gives exactly the same results as the M/χ approach prior to cracking but after cracking has an advantage over the M/χ approach in that it can quantify the mechanics of tension-stiffening, that is allow for bond slip and its effect