Flexural rigidity

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

Simple Nonlinear Flexural Stiffness Model for Concrete Structural Walls

Abstract: A trilinear bending moment–curvature model is proposed for the nonlinear static (pushover) analysis of concrete walls. To account for the effect of cracking on the flexural stiffness of concrete walls in a simple yet accurate way, the elastic portion of the bending moment–curvature relationship is modeled as bilinear. To account for the influence of cyclic loading on tension stiffening of cracked concrete, the concept of upper-bound response for a previously uncracked wall, and lower-bound response for a severely cracked wall is introduced. To validate the proposed model, the results of a large-scale test on a slender concrete wall are compared with predictions from the model. The application of the proposed model in a pushover analysis of a 131-m-(430-ft) high coupled-wall structure demonstrates the importance of accurately modeling the nonlinear flexural stiffness of concrete walls.

On the Quasi-Static Design of Machine Tool Spindles:

Abstract: The paper simplifies the analysis of the general multi-stepped spindle-bearing system model. Various design parameters are considered with the objective of attaining high static stiffness in the cutting zone. Parameters considered in the study include bearing spacing and stiffness, dimensionless flexural stiffness, number and length of the steps, effect of the driving force and the reaction moment exerted at the central front bearing. The calculations enable optimization (for maximum stiffness) at the chuck for short overhang spindles such as those of lathes.The most effective design parameter is the optimum bearing spacing, demonstrated in the study by evaluating the exact analytical solution of the derived equations.

Behaviour of bird-beak square hollow section X-joints under in-plane bending

Abstract: An experimental investigation was conducted on bird-beak square hollow section (SHS) X-joints under in-plane bending. A total of nine specimens including traditional, square bird-beak and diamond bird-beak SHS X-joints were tested. The test results of joint strengths, failure modes, axial load–vertical displacement curves, bending moment–local deformation curves, bending moment–rotation curves and load–strain distribution curves of all specimens were reported. The corresponding finite element analysis (FEA) was also performed and calibrated against the test results. Therefore, an extensive parametric study was carried out to evaluate the effects of geometric parameters ( β , τ and 2 γ ) on the behaviour of bird-beak SHS X-joints under in-plane bending. It is shown from the comparison that the ultimate loads and initial flexural stiffness of all specimens under in-plane bending increased with the increase of the β ratio. Furthermore, the ultimate loads and initial flexural stiffness of traditional, square bird-beak and diamond bird-beak SHS X-joints under in-plane bending increased progressively with the same β ratio, whereas the corresponding ductility decreased progressively. On the other hand, the joint strengths obtained from the test and parametric study were compared with the design strengths calculated using the current Eurocode 3, IIW Specification and Christitsas׳s equation. It is shown from the comparison that the current Eurocode 3 is quite conservative for the traditional SHS X-joints under in-plane bending, whereas the current IIW Specification and Christitsas׳s equation are generally appropriate for the traditional and square bird-beak SHS X-joints under in-plane bending, respectively. The new design equations were proposed for the square bird-beak and diamond bird-beak SHS X-joints under in-plane bending, which were verified to be accurate.

Exact solutions for variable-thickness inhomogeneous elastic plates under various boundary conditions

Abstract: In this paper, an exact solution to the governing equations of the bending of a variable-thickness inhomogeneous rectangular plate is presented. The procedure is applicable to variable-thickness inhomogeneous rectangular plates with two opposite edges simply supported. The remaining ones subjected to a combination of clamped, simply supported, and free boundary conditions and between these two edges the plate may have varying thickness. The procedure is valuable in view of the fact that tables of deflections and stresses cannot be presented for variable-thickness inhomogeneous orthotropic plates as for uniform-thickness homogeneous isotropic plates even for commonly encountered loads because the results depend on the inhomogeneity coefficient and the orthotropic material properties instead of a single flexural rigidity. Numerical results, useful for the validation or otherwise of approximate solutions, are tabulated. The influences of the degree of the inhomogeneity, aspect ratio, thickness parameter and degree of non-uniformity on the deflections and stresses are investigated.