Partial, Composite Fractional Operators, and Their Properties and Applications

The paper discusses the properties of the partial fractional integrals, the partial fractional derivatives, and the composite fractional integrals and derivatives. Some basic formulas are derived; and the relations between the Riemann-Liouville and Caputo ones are also presented. Finally, as the specific application, a two dimensional Abel integral equation is solved

Partial, Composite Fractional Operators, and Their Properties and Applications

The paper discusses the properties of the partial fractional integrals, the partial fractional derivatives, and the composite fractional integrals and derivatives. Some basic formulas are derived; and the relations between the Riemann-Liouville and Caputo ones are also presented. Finally, as the specific application, a two dimensional Abel integral equation is solved

Numerical and Experimental Investigation of the Mechanical Behavior of Cable-Supported Barrel Vault Structures with Varying Temperature

The cable-supported barrel vault (CSBV) structure system is a new type of hybrid spatial steel structure based on a beam string structure (or truss string structure), suspendomes, and cylindrical lattice shells. Steel cables (e.g., steel wire rope cables, steel strand cables, semiparallel steel tendons, and steel rods) are key components of CSBV structures. However, they have different elastic moduli and thermal expansion coefficients. In this study, the roof of a textile workshop (the first CSBV structure in China) was analyzed with four types of cables under the effect of varying temperature. Under half-span loading and full-span loading, the structural internal force and displacement at varying temperatures were obtained from finite element models employing four different types of steel cables. The internal force, displacement, and horizontal arch thrust changed linearly with increasing temperature. Moreover, the dynamic characteristics of CSBV with varying temperature were analyzed. The frequency of the CSBV changed linearly with increasing temperature. Based on the dynamic characteristics of CSBV with varying temperature, a seismic response time-history analysis was performed. The variation in the maximum responses of the internal force, displacement, and horizontal arch thrust was obtained. In each case, the mechanical behavior of the CSBV with semiparallel steel tendon cables was strongly affected by the temperature. Therefore, semiparallel steel tendons are not recommended as components of CSBV in cases where large temperature changes can be expected. Thereafter, a scale model of a CSBV was designed and used for experiments and corresponding finite element analyses under varying temperature. Experimental results show that the finite element method is effective for analyzing the mechanical behavior of CSBV under varying temperature

Observer Kalman Filter Identification of Suspen-Dome

A number of Suspen-Dome structures have been built, but there is some difficulty in using experimental data to obtain good modal parameters, especially modal damping. In this paper, an ANSYS numerical simulation of the 35.4 m span Suspen-Dome is presented. Firstly, the natural vibration characteristics of Suspen-Dome and dynamic response under some random forces were obtained. Then the results of the numerical simulation established that 60 modes are sufficient for a reasonable dynamic model. This model is used to represent the Suspen-Dome dynamic behavior, and OKID is then used to try to identify a model from simulated data. A 400-order model generated from OKID is shown to contain the 60 modes from ANSYS and is shown to give good predictions of the dynamic behavior of Suspen-Dome. The results of this paper can confirm that it can be a very efficient tool for the identification of models of Suspen-Dome dynamics

Initial Shape Analysis and Experimental Study of Air-Supported Membrane Structure Considering Cable–Membrane Contact

The cable net and membrane of the air-supported membrane structure transmits the load through mutual extrusion, and the contact interaction between the cable net and membrane should be considered in the initial morphological analysis stage. In this paper, a scale model was designed according to a large-span air-supported membrane structure engineering project, and the shape and force of the structure were measured. At the same time, a finite element model of cable–membrane contact was established, and its interaction behavior was regarded as a combined contact state and sliding contact state. The results show that the influence of different contact state analyses on the prestress of the cable net is obvious, and the influence of the sliding contact between the cable and the membrane should be considered in the design of the membrane structure

A novel winding–wedge anchorage for CFRP straps: Conceptual design and performance evaluation

Carbon fibre-reinforced polymer (CFRP) straps can be utilised as tension members in structures on account of their high-strength properties. The development of an effective anchorage device for CFRP straps that can fully utilise the strength of straps before anchorage failure is an ongoing technical challenge. To address such knowledge gap, a novel anchorage device termed winding-wedge anchorage that combines winding and wedge anchorage mechanisms is reported herein. For the winding anchorage component, different numbers of winding turns are applied. For the wedge anchorage component, three different types of wedge anchorage systems are investigated namely bonding, friction clamping, and friction non-clamping. Initially, the working mechanism, theoretical winding–wedge anchorage model (herein theoretical model), and design parameters are determined. Experimental and finite element analyses are then reported to assess the behaviour of the anchorage including failure modes and anchorage efficiencies. The accuracy of the theoretical model is also reported. It is concluded that the efficiency of the anchorage device is primarily dependent on the wedge anchorage component. Moreover, the bonding wedge anchorage component performed better than the other two wedge anchorage systems. The theoretical model and experimental results revealed that 1.5 winding turns results in an optimal interaction between the winding and wedge anchorages components

Performance and measurement devices for membrane buildings in civil engineering: a review

Lightweight and flexible membranes offer different façades for buildings (suitability, competitive costs, durability, and other benefits) compared to traditional building materials. Increasing attention is being paid to membrane structures in the civil and industrial sectors. Acquiring response data or environmental characteristics directly from a model or building is the most straightforward approach to analyzing the properties of membrane structures, which also contributes to the development of theoretical studies and simulation methods along with the enactment of specifications. This paper provides a comprehensive overview of membrane structure performance, including mechanical, thermal, and energetic aspects, alongside the deployment and deflation of inflatable types. Furthermore, the devices used to monitor the structural response are summarized. The constitution of the structure is the most critical factor affecting its performance. A proper design would offer enhanced mechanical properties and thermal environments with a reduction in energy consumption. Non-contact measurement technology has the advantage of causing no structural disturbance and is low cost, but it lacks practical application in membrane buildings. The achievements and limitations of previous studies are also discussed. Finally, some potential directions for future work are suggested