Search

A floating viscoelastic composite structure with generalized elastic constraints, in which the material–structure-wave interaction induces energy dissipation, is analyzed with a novel cross-scale integrated hydro-viscoelastic model. A double-level three-dimensional (3D) representative volume element model coupling mesoscale reinforced particles to a macroscale composite structure is established to obtain the structure's viscoelastic dynamic equation. Therefore, a hydro-viscoelasticity analytical model for floating composite structures with arbitrary elastic constraints under wave action is developed in the context of potential flow theory. In the process of solving the velocity potential, the dispersion equation of the water covered by the composite structure is derived. The hydrodynamic and mechanical behaviors of the floating composite structure, including the reflection coefficient, transmission coefficient, dissipation coefficient, deflection, shear force, and bending moment, are comprehensively calculated, which depend on the cross-scale integrated effects of wave action, structural features, material characteristics, and constraint combinations. This material–structure-wave integrated model would be useful to elucidate the hydro-viscoelastic dissipation mechanism of marine structures. [ABSTRACT FROM AUTHOR]

The high-payload transporter is a key part of the multipurpose deployer, which is important for realizing the remote handling of tokamaks. This paper presents an analysis of the key joint between the high-payload transporter and the design of the test platform. The kinematic, structural, and load characteristics of the main joints of a heavy-duty manipulator were analyzed according to the peculiarity of high precision, large length, and heavy load of the high-payload transporter. Joint No. 4 (J4) was determined to be the key joint of the high-payload transporter. The peak torque, bending moment, and shear force of J4 under working conditions and seismic conditions were determined via numerical simulations. The functions and key technical parameters of the test platform for J4 were determined according to the test analysis results and numerical simulation. The structure of the test platform was designed, and its working principle was described. [ABSTRACT FROM AUTHOR]

An arch bridge is a mainly horizontal deck with an arch as its load-carrying structure. The arch works by transferring the weight and other external vertical loads into a horizontal thrust on the abutments placed at both sides. When the main load on the arch is the homogeneously distributed deck weight, and the arch is properly shaped, the arch rib is subjected to pure compression along its whole extension. Both tensile forces along the arch rib and shear forces transversal to it are absent. Bending moments vanish as well. This has made possible the use of masonry for arch bridges, which uses materials such as stone, brick, and concrete that are strong in compression but very weak to tension and shearing. In the following sections, we determine mathematically this optimal arch shape, which turns out to be a parabola. The novelty is that these well-known results are obtained using just basic algebra and trigonometry, without any mention of infinitesimal calculus, including in the demonstration of the absence of shearing forces. Subsequently, the method is extended to cable suspended bridges. [ABSTRACT FROM AUTHOR]