Advanced Materials Research Vol. 803

Abstract: The microstructure of X80 pipeline steel in different directions were observed by SEM technique and its effective grain size and misorientation were statistically analyzed by EBSD system. Based on these results, the mechanical properties at 0°, 45° and 90° to the rolling direction of X80 pipeline steel were studied. The results show that, owing to finer grain size and less low-angle grain boundaries, strengths and impact toughness of X80 pipeline steel at 90° direction are optimal. While the pipeline steel possesses finer grain size, more high-angle grain boundaries and less low-angle grain boundaries, the crack propagation is effectively suppressed, then its impact toughness is improved.

Abstract: in this paper, the reflection and transmission problem of the coupled transverse displacement and transverse rotational waves at the imperfect interface between two different micropolar solids are studied. First, the boundary conditions between two micropolar solids with imperfect interface are used to derive the linear algebraic equation sets. Then, the linear algebraic equation sets are solved numerically and the results are shown graphically. Finally, the influence of the interface parameter reflecting the imperfect degree of interface on the reflection and the transmission coefficients are discussed based on the numerical results.Keyword: reflection and transmission, imperfect interface, micropolar solid, coupled waves.

Abstract: This paper proposes a method that automatically adjusts the transmission power of ZigBee end-devices based on received signal strength indication (RSSI). Under normal communication condition, automatically adjusting the transmission power of ZigBee end-devices by constructing a negative feedback control system, and it uses the controller with relay characteristics, keep it in the smallest state of transmission power, which effectively reduces the energy consumption of the end-devices. Compared with the traditional methods of statically adjusting transmission power, experimental results show that the method proposed is more suitable for network with frequently status changes, making the stability and low-power performance of ZigBee network system significantly improved.

Abstract: As the temperature reduces in heated waxy oil pipeline, wax crystal continues to precipitate. The wax sediment reduces the pipeline transmission capacity, increases the friction resistance and raises power consumption. To restore the pipeline transmission capacity and ensure the safety operation of pipeline, regular wax removing is needed. Taking the transition of flow states into consideration, different formulas of temperature and friction drop under different flow states are applied. Wax precipitation and running cost corresponding to different flow states are obtained, and the best pigging circle is determined. Finally, the effect of different flow states on temperature drop, pressure drop and pigging circle of heated waxy oil pipeline is analyzed.

Abstract: Aimed to implement effective maintenance to ensure that the highway electromechanical system performs its intended functions, the output results of the fore-warning system are considered as the basis of maintenance policy. The fore-warning system is built based on the study of the fault features and causes of highway electromechanical system. As a failure warning information platform, the fore-warning system of highway electromechanical system analyzes fault factors and the relationship associated, in order to perform timely appropriate preventive maintenance measures at the right time. Taking advantage of Fault Tree Analysis, failure rates or failure probabilities of individual basic events existing in the complex system are estimated, which would be synthesized to determine whether the system failure rate reaches the threshold.

Abstract: The drag of liquid flow is of interest in micro/nanoscale. Electroviscosity is one of the important factors which can affect drag. By applying electric filed between liquid and surface, the surface charge density can be changed, leading to a change of electroviscosity. This paper experimentally studied the effect of applying electric field on the surface charge density, and analyzed the change of electroviscosity with applying electric field. The electroviscosity is found abated with applying electric field which will decrease the drag of liquid flow.

Abstract: Reactor Pressure Vessel is the core equipment in the nuclear power plant, many problems happen during the manufacturing process of localization. Through the statistical analysis on non-conformance and problems detected by quality surveillance, the characteristics and difficulties of RPV quality control in domestic manufacturing process is researched, and the basic problem and the direction of improvement has been analyzed. The data, contents and opinions will further provide reference for RPV and other similar equipments manufacturing quality control.

Abstract: In view of the defects in the traditional aeolian vibration damping method for transmission line that repeated tests have to be undertaken in addition to the method's marked error, this article analyzed the calculating method for conductor anti-vibration test using the energy balance method, and improved the test method for self-damping characteristic and the design method for arrangement damped wire; improving design efficiency and accuracy. Laboratory simulation test which was carried out in connection with the actual engineering parameters verified the strong applicability of the improved method in vibration damping design.

Abstract: The long-span suspension clamp is used to suspend conductor or ground wire on the long-span tangent tower ^[. Long-span suspension has impact on the operation safety and investment of long-span projects. This paper makes analysis and comparison of different models of suspension clamps and studies the long-span suspension clamp for transmission line over Han River in terms of model and material selection, design & calculation, manufacturing process and test, etc., in combination with features for crossing over Han River.

Abstract: this paper presents the rendering method of galloping distribution plan for power transmission line based on the meteorological geographical model by summarizing theory on division of galloping region, e.g. frequency method and galloping coefficient method. Meteorological geographical method is to account and analyze icing galloping conditions of power transmission line over the years and sum up meteorological and topographic features and laws to create meteorological and topographic model for icing galloping and work out division and classification if galloping region based on running experience so as to establish standard technical system for rendering galloping distribution plan and complete the galloping distribution plan.