Applied Mechanics and Materials Vols. 71-78

Abstract: According to the characteristics of the bicycle traffic flow, the bicycle green time is divided into the maximum queue dissipation time and the time of bicycle cluster center running to the opposite lane, and the formulas are given respectively in this paper. Validation is done based on intersection bicycle data of Beijing city and Tianjin city. Results show that the green time calculated by considering the bicycle cluster meets the interval of bicycles passing through the intersection, which enriches the signal timing algorithm at signalized intersection.

Abstract: Based on bionics and digital technology, the efficient methods to create and control architectural bionic forms through parametric technology are discussed. The harmonic integration of morphological bionics with mechanical logics in the digital space, is considered as the key point in structural morphological design with the structural mechanics theory.

Abstract: Good construction site safety control lead to successful project management, while, the layout of a construction site plays a major role in the safety. The paper aims to reduce the likelihood of accident happened by optimization construction site layout via ant colony optimization (ACO) model. A case of residence building was used to evaluate proposed ACO model. The results showed that the feasibility and effectiveness of the proposed ACO model.

Abstract: Taiwan’s building laws are very rigorous for envelope load of various buildings, and building envelope load should be calculated according to the Technical Code for Energy Conservation Design of Buildings. The complex calculation may undermine cooperative initiative of the industry. If computer aid can be used, the time for calculation and laws search can be save. To provide practical computer-aided calculation tool of envelope load for builders and academic departments, this study designed a computer-aided software BEEP-2010 which can quickly calculate whether the designed building meets the regulations. Java is used to write programs for this software. The database system applies the Relational Database. ER-model is used to normalize the database design. The user interface design adopts graphics mode to simplify operation interface. As long as the user understands basic concept of the envelope load, he/she only needs statistics of the area data and print the calculation result in the form of standard window to reduce the inconvenience in table search. Thus, this can greatly improve calculation efficiency of envelope load of Taiwan building businesses and help promote green buildings.

Abstract: The white LED and high-pressure sodium lamp (HPS) are used to simulate highway tunnel lighting under different background brightness (abbreviated as B) conditions, from a series of reaction time tests, the result shows that white LED can provide shorter reaction time for observers compared with HPS, further research suggests under the mesopic vision, different kinds of light sources maybe have unlike brightness, although which is identical under the photopic vision. From the luminous spectrum test and mesopic vision spectral luminous efficiency function fitting calculation, the mesopic equivalent brightness can be determined with certain light source and B value. This conclusion would provide a more accurate and lower energy consumption lighting design method for highway tunnel.

Abstract: This paper designed a signal acquisition and analysis system based on the characteristics of the graphical programming language of LabVIEW. The system adopted NI USB -9234 data collection card, applied with the virtual instrument and related technology for the signal collecting and processing system. The system also has dual-channel data acquisition, real time data acquisition, signal analysis in time domain and frequency domain, FFT implementation Waterfall conversion, signal simulation capabilities. On the basis of analysis the systems functional requirements, a detailed description of the functional programming and design of the front panel is approached. At last the feasibility of system is experimental inspected and detailed. Experiments have shown that the virtual instrument is a good solution to the efficient implementation of various missions.

Abstract: When outdoor air flowing through the tailrace tunnel, it will be handled and its thermodynamic conditions will change under the differences of temperature and water vapor pressure between air and water surface, air and tunnel wall. Utilizing the handled air for space cooling in hydropower station is an energy saving, environmental protection and renewable application of natural cold source. In this paper, a detailed quasi-three-dimensional mathematical model of heat and moisture transfer of tailrace tunnel ventilating was developed and validated against the field test data from Yingxiuwan hydropower station, and the validation shows that the model predicts the test results very well. The model can be used to predict the heat and moisture performance of tailrace tunnel ventilating system.

Abstract: This research presented the damage identification problem of frame structure using the wavelet transform of strain mode. Solving strain modal parameters of plane frames with cracks by means of the finite element theory, applying the gauss2 wavelet transform to analyze the stain mode of plane frame, and denoising the wavelet coefficients of the strain mode by db3 wavelet, then the location of crack of the plane frame could be identified by the maximum of wavelet coefficients after denoising. Taking one-layer plane frame as an example, this research gave the finite element model of framework with sheet crack (non-through surface crack and internal crack), calculated the strain mode of the structure, and identified the location of cracks by wavelet analysis of strain mode. Results show that this method is able to identify the damage of frame structure. Numerical calculation shows that the approach is effective. This paper provides a valuable reference of structural damage identification and diagnosis in engineering applications.

Abstract: By means of the wavelet analysis theory, the damage identification of elastic plate was studied. Adopted the finite element method to analyze the dynamic character of the plate and applied the method of Lanczos for calculating the strain mode, and the strain mode is analyzed by mexh wavelet (Mexican Hat wavelet). The location of the declining stiffness is identified by the place where maximum of wavelet coefficients appears. Therefore, this method is applied to the elastic damaged plate. Three types of damaged regions in rectangular simply supported plate are recognized, which indicates this method is effective and accurate. And this method has a certain value in the project application.

Abstract: Multi-pile composite foundation is a method of ground improvement that involves using different pile types with different lengths and diameters beneath the same raft. The types of piles are chosen to mobilize the strength and stiffness of the soil at shallow depths. CFG (cement–flyash–gravel) pile and powder spraying pile have been widely applied in civil engineering, and gradually in highway foundation engineering. But the settlement of the pavement reinforced by the two types of piles has seldom been studied. In the present paper, the numerical simulation software FLAC3D is adopted to simulated the highway foundation reinforced by CFG pile and powder spraying pile , the spacing of piles and cushion thickness are changed, the settlements of the pavement are obtained to give guidance for the real practice.