Applied Mechanics and Materials Vols. 105-107

Abstract: This paper discusses the composition and structure of B/S mode-based rotating machinery remote status monitoring and fault diagnosis system, builds the system network model, makes detailed introduction of fault diagnosis mode, system hardware composition, software platform and system realization process, and carries out laboratory simulation on the feasibility of remote monitoring diagnostic system.

Abstract: The advantages and disadvantages of traditional gearbox fault diagnosis method based on autocorrelation, spectrum-zoom, Hilbert demodulation and cepstrum analysis are respectively analyzed. Then a gearbox fault diagnosis method is presented, which integrates autocorrelation, spectrum-zoom, Hilbert demodulation and cepstrum analysis. Finally, vibration data of the pitting gear is measured by using QPZZ-II rotating-machinery fault simulating system. The result shows that the improved method proposed in this paper is effective for the fault diagnosis of the pitting gear.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications.. The best is to read these instructions and follow the outline of this text. Please make the page settings of your word processor to A4 format (21 x 29,7 cm or 8 x 11 inches); with the margins: bottom 1.5 cm (0.59 in) and top 2.5 cm (0.98 in), right/left margins must be 2 cm (0.78 in). We shall be able to publish your paper in electronic form on our web page http://www.scientific.net, if the paper format and the margins are correct. Your manuscript will be reduced by approximately 20% by the publisher. Please keep this in mind when designing your figures and tables etc.

Abstract: According to the wheel-rail interaction characteristics and the restriction condition of track, a wheel-rail lateral force continuous measurement method is researched. This paper validates the feasibility of rail web bending moment difference methodthough simulation calculationand field measurement. The results shows that this method is absolutely capable of achieve continuous measurement of wheel-rail lateral force.

Abstract: The study shows that, the vibration of structures and members has very obvious self-excited vibration characteristic under the action of fire. Random signals for acceleration distribution of composite beams of the overall structure under the action of fire are collected and auto-spectrum analyzed in this paper. The result shows that: the fire causes self-excited vibration of composite beams of the overall structure. As the internal forces cause re-distribution and structure connections are damaged, amplitude, frequency and vibration characteristic excited by external forces of composite beams are different, and fluctuating decrease occurs to vibration frequency of composite beam in the test. Test results provide data support for the establishment of fire vibration theory and healthy detection of structures in case of fire.

Abstract: On the basis of the review of the present situation and existing problems in structure real-time monitoring system, the paper designs and develops a structure vibration real-time monitoring system. In process of the application, spectral analysis was carried out through fast Fourier transform (FFT) technology, at the same time, the deformation and inherent mode shapes are monitored. In one words, the system realizes synchronously the real-time display of the structural total characteristic, mode shapes, time and frequency signals of key testing points on computer screen. In order to prove the validity of the system, the paper the paper takes a simple-supported beam for an example and receives a satisfying result.

Abstract: This paper demonstrates the feasibility of a new structural damage alarming method based on statistics. The abnormal index was introduced to analyze the benchmark structure in frequency domain. The results show the abnormal index defined in sense of statistics indicates the abnormity of corresponding test cases clearly.

Abstract: To get environmental action information for structural life-cycle design and durability design, the air temperature of most Chinese cities from 1951 to 2009 was employed to analyze the applicability of half normal distribution in expressing freeze-thaw action spectrums. A use of spectrum to predict concrete life under freeze-thaw action was performed as well after compiling the freeze-thaw action spectrum of Harbin. In this paper, weather data such as Beijing, Hohhot, Yining and Zhengzhou were analyzed and results showed that half normal distribution is available for most areas of China. Meanwhile, to account for the effect of freezing temperature, freeze-thaw life of a common concrete in water-saturated state in Harbin was predicted to be only about 6 years based on quantitative analysis of the concrete frost resistance.

Abstract: The blast-resistant performance of columns which are the most important component in the whole structure is a crucial factor which influences the safety of the structures subjected to the blast loads. Studying dynamic responses of RC columns under the blast loading and improving the blast-resistant performance can prevent the structure from progressive collapse due to the damage of the columns in the blast loading, and give people more time to escape from the building in a dangerous situation. Then the same parameters are used to analyze the dynamic responses of RC columns under three typical blast loads. Conclusion can be used for structure blast-resistant design.

Abstract: Girders with singly symmetric sections are more efficient and economical then the double symmetric sections. However, the theoretical moment calculations for singly symmetric sections are not an easy task. The difficulty comes from some of the evaluation of torsion properties. Current AISC specifications [1, 2] are not provided the theoretical formulas for the critical moment curves of singly symmetric girders. In AISC specification [1], which revisions the residual stress design to influence the limiting buckling moment strength. This study introduces the singly symmetric girders design methods with theoretical and design manual, and compared the limiting buckling moment with the specification of AISC [1, 2]. It will enable practicing engineers to perform more in-depth evaluation in their routine deigns.

Abstract: Nonlinear finite element analysis (FEA) for the torsion behavior of reinforced concrete '+'-shaped columns with various axial load ratios was carried out by the general software ANSYS. Then a comparison between the FEA calculations and the test results is made. The numerical examples show that: (1) the cracking torque and ultimate torque of reinforced concrete '+'-shaped columns under the combined actions of axial force and torque can be predicted with a reasonable accuracy. (2) the axial ratio has significant effects on the torsion behavior '+'-shaped columns. The cracking torque and ultimate torque of '+'-shaped columns increase with an increase of axial load ratio. Comparing with reinforced concrete '+'-shaped column with an axial load ratio of 0.063, the cracking torque and ultimate torque of reinforced concrete '+'-shaped columns with axial load ratios of 0.189 and 0.314 were increased by 28.3% and 71.9%, 79.4% and 96.0%, respectively.