Shape determining of a loaded cable via total displacements
Abstract Cable structures are very efficient (in economic aspect) when applied to cover large spans. The cable structure consists of a single cable or a network of cables. The cable attractive feature is the highest ratio of strength to weight amongst other carrying structural elements, usually applied in engineering practice. But a cable is a specific structural element able to response only one type of deforming ‐ tension (flexural rigidity actually vanishes). Therefore, when loaded a cable shapes the form to resist tension only. This adaptation is followed by large nonlinear displacements. Thus, the nature of geometrical nonlinear cable behavior is quitie a different from that of rigid structural elements. Both elements response via small deformations when loaded, but large displacements of a cable are conditioned by its adaptation to loading, and those of rigid structural elements ‐ by actual deformations. One can also note that deformations of a cable are significantly less than those of rigid struct...
THE SIMPLIFIED ANALYSIS OF THE ASYMMETRIC SINGLE-PYLON SUSPENSION BRIDGE WITH RIGID CABLES
Suspension bridges are characterized by exceptional architectural expressions and excellent technical and economic properties. However, despite all advantages, suspension bridges have a few negative features. Suspension bridges with flexible cables share excessive deformation caused by the displacement of kinematic origin. In order to increase the stiffness of suspension bridges, an innovative structural solution refers to rigid cables used instead of the flexible ones. The paper describes a methodology for calculating an asymmetric single-pylon suspension bridge with rigid cables considering installation features. Also, the article presents the numerical simulation of the bridge and determines the accuracy of the proposed methodology.
Numerical tools applied to power reactor noise analysis
In order to be able to calculate the space- and frequency-dependent neutron noise in real inhomogeneous systems in two-group theory, a code was developed for the calculation of the Green's function (dynamic transfer function) of such systems. This paper reports on the development as well as the test and application of the numerical tools employed. The code that was developed yields the space-dependence of the fluctuations of the neutron flux induced by fluctuating properties of the medium in the two-group diffusion approximation and in a two-dimensional representation of heterogeneous systems, for both critical systems and non-critical systems with an external source. Some applications of these tools to power reactor noise analysis are then described, including the unfolding of the parameters of the noise source from the induced neutron noise, measured at a few discrete locations throughout the core. Other concrete applications concern the study of the space-dependence of the Decay Ratio in Boiling Water Reactors, the noise-based estimation of the Moderator Temperature Coefficient of reactivity in Pressurized Water Reactors, the modeling of the beam- and shell-mode core-barrel vibrations in Pressurized Water Reactors, and the investigation of the validity of the point-kinetic approximation in subcritical systems driven by an external source. In most of these applications, calculations performed using the code are compared with at-power plant measurements. Power reactor noise analysis applications of the above type, i.e. core monitoring without disturbing plant operation, is of particular interest in the framework of the extensive program of power uprates worldwide.