Optical fiber Bragg grating (FBG) has been recognized as an outstanding high-performance local monitoring sensor and is largely applied in structural health monitoring (SHM). This paper proposes a series of fiber-reinforced polymer- (FRP-) packaged optical fiber Bragg grating strain sensors to completely meet the requirements of rough civil engineering infrastructures, and their sensing performance under normal environment and harsh environment is experimentally investigated. It is experimentally and theoretically proved that FRP-packaged FBG strain sensors maintain excellent sensing performance as the bare FBG sensor under a harsh environment, and their durability is significantly enhanced due to the FRP materials. These FRP-packaged FBG strain sensors are successfully applied in the SHM system of Aizhai Bridge.
Carbon fiber–reinforced polymer (CFRP) rods have been considered as a candidate material for prestressed concrete applications because of their superior properties. For current applications, successful use of CFRP rods is linked to an efficient anchorage system design. This paper presents a newly developed anchorage system for CFRP rods and the design concept that the extrusion process is used to generate gripping force. The proposed anchorage system consists of a steel barrel and an aluminum sleeve, and an extrusion region is designed on the outside of barrel to generate a suitable contact pressure distribution on the CFRP rod. A mathematical model was proposed to estimate the contact pressure on the CFRP rod and the capacity of anchorage system. The simulation of extrusion and loading process was conducted with a three-dimensional (3D) finite-element (FE) model. The key design parameters of anchorage system were analyzed to obtain an optimized parameter combination. The experimental validation showed that the new anchorage system is capable of allowing the CFRP rod to attain the ultimate tensile strength.
The causes of greater energy loss for throttling in the fan and pump were analyzed, and the principle of frequency control in energy saving were analyzed on the basis of the similarity theory, too. To export the relationship between the power saving rate and flow, the relationship between the energy consumption of throttling regulation and flow were described. Comparison between frequency control and throttling regulation in changing the flow shows that motor frequency control applied in pump and fan is an efficient way to save power. It confirms that under meeting the similarity condition, the power saving rate of theoretical calculation is consistent with the measured data.
The present SO2 gas detection technology and research were studied. The paper aimed at the problems of low SO2 concentration, much interference with gases, long response time in the flue gas desulphurization process. The improvements were made based on non-dispersive infrared detection. Gas filter correlation technology was adopted to filter out the interference of other gases. In the hardware, thermoelectric release detector was used to detect the signal to shorten the response time. All these efforts are made to meet the requirement of realtime and on line control in the desulphurization system.
Multi-objective arithmetic NSGA-II based on Pareto solution is investigated to deal with integrated optimal design of speedability and manoeuvre performances for submersible. Approximation model of resistance for serial revolving shape is constructed by hydrodynamic numerical calculations. The appraisement criterions of stability and mobility are calculated from linear equation of horizontal movement by estimating hydrodynamic coefficient of submersible. After optimization, the scattered Pareto solution of drag and turning diameter are gained, and from the solutions designer can select the reasonable one based on the actual requirement. The Pareto solution can ensure the minimum drag in this manoeuvre performance or the best manoeuvre performance in this drag value.
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