Flexural rigidity

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

Flexural rigidity of layers and its manifestation in the vibrational characteristics of strongly anisotropic layered crystals. Characteristic frequencies and stability conditions in quasi-two-dimensional systems

Abstract: The reasons for the appearance of flexural rigidity of layers in strongly anisotropic layered crystals are investigated. Structures consisting of loosely bound monatomic layers (specifically, graphite) as well as formed loosely bound structural elements each consisting of several monolayers which are coupled much more strongly with one another (for example, in dichalcogenide transition metals) are examined. The effect of the flexural rigidity on the phonon spectra of these compounds—quasi-flexural bending of the dispersion curves of phonon modes polarized in a direction normal to the layers—and the particularities appearing in the phonon densities of states as a result of quasi-flexural vibrational branches crossing low-frequency optical modes are analyzed.

Scaling modulus as a degree of freedom in the design of locust legs

Abstract: Previous work has shown that the scaling of mechanical behaviour in bending of the metathoracic tibiae of the African desert locust (Schistocerca gregaria) is not predicted by the scaling of external dimensions. The flexural stiffness of the tibia scales to (body mass)1.53, which is similar to the predictions of the elastic similarity model of scaling. The external dimensions, however, scale in a manner that produces relatively more elongate limb segments ­ an observation that differs from the predictions of any existing scaling model. In this paper, we examined two alternative hypotheses to explain this uncoupling of morphology and mechanics: (1) that the load-bearing cuticular material is distributed in the legs in a manner that is not indicated by changes in external dimensions, or (2) that the stiffness of the cuticular material is altered to produce the observed scaling of flexural stiffness. The second moment of area (I) scaled to (body mass)1.19, which was similar to scaling I to (tibial radius)4. This indicates that the relationship between the external dimensions of the tibiae and the specific distribution of load-bearing material is conserved independently of scale. Therefore, the locust achieves the observed scaling of flexural stiffness by altering the modulus of the load-bearing cuticular material. In fact, the time-dependent modulus (E') scales to (body mass)0.311. In essence, the scaled material stiffness provides a degree of freedom in design in addition to external morphological dimensions in accommodating the changing demands placed on a skeletal structure with increases in body size.

Bending Hysteresis of Plain Woven Fabrics in Various Directions

Abstract: Many researchers have studied the bending rigidity of woven fabrics in various directions, but there have been no reports on anisotropy in bending hysteresis. In this work, existing models for predicting the bending rigidity of woven fabrics are applied to bending hysteresis in various directions. A wide range of cotton plain woven fabrics is examined by comparing theoretical data with experimental results. The results show that Cooper's model is the most reliable in predicting polar diagrams of bending hysteresis in cotton plain woven fabrics. The results also indicate that the shape of polar diagrams of bending hysteresis along the weft direction spreads outward with an increase in the ratio V introduced by Cooper.