Wyniki wyszukiwania - BazTech

1

Study of the force and deformation characteristics of subsea mudmat-pile hybrid foundations

Kong D., Deng M., Liu Y., Tan X.

Polish Maritime Research

|

2018

|

S 3

43--53

EN

To study the force and deformation characteristics of subsea mudmat-pile hybrid foundations under different combined loads, a project at a water depth of 200 m in the South China Sea was studied. A numerical model of a subsea mudmatpile hybrid foundation is developed using the numerical simulation software FLAC3D. The settlement of the seabed soil, the bending moments of the mudmat, and the displacements and bending moments along the pile shaft under different load combinations, including vertical load and horizontal load, vertical load and bending moment, and horizontal load and bending moment load, are analyzed. The results indicate that settlement of the seabed soil is reduced by the presence of piles. The settlement of the mudmat is reduced by the presence of piles. Different degrees of inclination occur along the pile shaft. The angle of inclination of pile No. 1 is greater than that of pile No. 2. The dip directions of piles No. 1 and No. 2 are identical under the vertical load and bending moment and are opposite to those under the other combined loads. The piles that are located at the junctions between the mudmat and the tops of the piles are easily destroyed.

2

The influence of VO2(B) nanobelts on thermal decomposition of ammonium perchlorate

Zhang Y., Tan X., Meng C.

Materials Science Poland

|

2015

|

Vol. 33, No. 3

560--565

EN

The influence of vanadium dioxide VO2(B) on thermal decomposition of ammonium perchlorate (AP) has not been reported before. In this contribution, the effect of VO2 (B) nanobelts on the thermal decomposition of AP was investigated by the Thermo-Gravimetric Analysis and Differential Thermal Analysis (TG/DTA). VO2 (B) nanobelts were hydrothermally prepared using peroxovanadium (V) complexes, ethanol and water as starting materials. The thermal decomposition temperatures of AP in the presence of 1 wt.%, 3 wt.% and 6 wt.% of as-obtained VO2( (B) nanobelts were reduced by 39 °C, 62 °C and 74 °C, respectively. The results indicated that VO2 (B) nanobelts had a great influence on the thermal decomposition temperature of AP. Furthermore, the influence of the corresponding V2O5, which was obtained by thermal treatment of VO2 (B) nanobelts, on the thermal decomposition of AP was also investigated. The results showed that VO2 (B) nanobelts had a greater influence on the thermal decomposition temperature of AP than that of V2O5.

3

Design of Rogowski Coil with external integrator for measurement of lightning current up to 400kA

Li Z., Zhang Q., Zhang L., Liu F., Tan X.

Przegląd Elektrotechniczny

|

2011

|

R. 87, nr 7

188-192

EN

Lightning is one of the most serious disasters in the electrical power grid, especially in the ultra-high and extra-high voltage power systems. The measurement of the lightning current parameters is of great importance for the investigation of lightning protection. The literature shows given its significant advantages over equivalent current transducers, the Rogowski coil is an increasingly popular method for current measurement of high amplitude and high frequency. However, there is little report focus on the lightning measurement on the transmission lines. In this paper, the lumped parameter model of the Rogowski coil with an external integrator is established to deduce the transfer functions as well as the bandwidth of the coil. Relationships between the sensitivity and coil parameters, such as coil dimension, integral parameters and number of turns of the coil, are investigated. Results show that the sensitivity of the coil increases with the increase of the sectional area and number of turns, or with the decrease of effective magnetic path, resistance and capacitance of the integrator. Based on the analysis of the experimental results, a Rogowski coil of the bandwidth from 2 kHz to 2 MHz and average sensitivity of 0.1144V/kA is developed for the measurement of lightning current up to 400kA. Furthermore, it is found that the measuring uncertainty is always caused by the off-center position of the current flowing through the coil. Combined with the affiliate circuit, the lightning current transducer is used to measure and locate the lightning current on the transmission line based on the designed Rogowski coil with external integrator.

PL

Pomiary prądów wyładowań atmosferycznych odgrywają dużą rolę w zabezpieczeniach. Obecnie pasek Rogowskiego staje sioę coraz popularniejszym narzędziem pomiaru prądów o dużej amplitudzie i dużej częstotliwości. W artykule przedstawiono cewki Rogowskiego w zastosowaniu do pomiarów w liniach przesyłowych. Zaprojektowano czujnik o pasmie częstotliwości 2 kHz - 2 MHz i czułości 114 mV/kA.

4

Sinusoidal phase modulating interferometer for real-time surface profile measurement

He G., Jiang H., Tan X.

Optica Applicata

|

2008

|

Vol. 38, nr 2

413-420

EN

The optical interferometry for the surface profile measurement is high accuracy, non-contact, and has a wide application in industry and scientific research. In this paper, a sinusoidal phase modulating (SPM) interferometer to realize real-time surface profile measurement is proposed, and its measuring principle is analyzed theoretically. In the SPM interferometer, the interferencje signal is detected by a high speed image sensor based on a low-speed CCD and a signal processing circuit is used to obtain the phase of each point on the surface. Therefore, the surface profile can be measured real time. The experiments measuring the surface profile of a wedge-shaped optical flat show that the measurement time of the SPM interferometer is less than 10 ms, the repetitive measurement accuracy is 5.2 nm. The experimental results confirm the validity of the SPM interferometer, and the merits of the interferometer is simple structure, high measurement accuracy.