Applied Mechanics and Materials Vols. 368-370

Abstract: In this study, set the empirical plane pilot area planting the groove (long 425cm × width 300cm × Height 20cm ) in the Taichung City residential area on the second floor roof, planting the groove bottom-up sequence laying frame high-rise, water proof layer, drainage layer,filter layer (non-woven, water-pottery-stone), the medium layer and planting of layer, planting the groove around the hollow brick interval income side to lighten the load. Noon hours exposed roof temperature of 25.49-37.56°C, green roofs surface only at 16.45-24.69°C, 17.74-24.79°C indoor temperature on the second floor, effectively prevent the roof surface temperature rise, and thus reduce the interior roof of the second temperature7.75-12.77°C. Building green roofs to cooling, mainly to reduce the building temperature, reducing air conditioning electricity consumption , accomplish cooling and energy-saving benefits.Compare different annual electricity consumption in the same period, extensive green roof to total electricity consumption of 860 K.Watts/hours , exposed roof to total electricity consumption in 1767 K.Watts/hours, 48.67% of the electricity consumption savings, to achieve energy efficiency.

Abstract: Among all kinds of renewable energy, solar energy is the most accessible and inexhaustible that can be applied unconditionally and has the least impact on the environment. We selected Beitou Library in the northern Taipei as the site to simulate the output energy of Photovoltaic panels (PV panels), since the building passed the Diamond Certification set by Taiwan Green Building Rating System (EEWH). The simulation was divided into two different angle settings: one set with a fixed angle for the whole year, and the other one with angles varied in certain time period. Results showed that in Taipei, when the set angle of solar panel was fixed, the output energy of Photovoltaic panels (PV panels) was the biggest when the set angle was 16 degree. In the situation of the variable angle setting, the shorter the cycle of angle variation, the lager the output energy of PV panels was.

Abstract: This study developed a heating mechanism applicable to hydrogen storage tank, in order to enhance the stability and durability of proton exchange membrane fuel cell (PEMFC). This study discussed two heating modes. The first mode was using heating wire to wind the hydrogen storage tank body. Heating wires were used to wind the upper, middle and lower parts of the hydrogen storage tank and the whole tank respectively for discussion. The second heating mode was to use the PEMFC cathode waste heat to heat the hydrogen storage tank body. This study discussed the variations of hydrogen release rate and tank body temperature with the hydrogen release time in different heating mechanisms. The research results can serve as reference for system design in various applications.

Abstract: Traditional project evaluation and optimal selection based on multi-objective programming and Delphi is highly dependent on subjective cognition, difficult to define weighted coefficient and without considering the uncertainty of the indexes. To solve these problems, this paper builds a multi-level fuzzy comprehensive evaluation model for the evaluation and optimal selection of diversion tunnels construction simulation schemes, and unites entropy weight and analytic hierarchy process (AHP) to calculate composite index weights. Through the comprehensive evaluation in a real-life diversion tunnels, this method is proved advanced and intuitive for giving objective evaluations and providing optimization suggestions for program development.

Abstract: By analyzing problems of highway subgrade fill height in Xinjiang plain terrain, this paper subdivided plain terrain types and proposed corresponding height control measures of subgrade fill based on features of different subtypes, which provides useful reference to similar engineering in plain terrain.

Abstract: In recent years, there has been a significant increase in the number of bridges which are being instrumented and monitored on an ongoing basis. This is in part due to the introduction of bridge management systems designed to provide a high level of protection to the public and early warning if the bridge becomes unsafe. This paper investigates a novel alternative; a low-cost method consisting of the use of a vehicle to monitor the dynamic behaviour of bridges. A truss vehicle-bridge model is used to test the effectiveness of the approach in identifying the damping ratio of the bridge with the time-delay neural networks (TNNs). A simulation study has been carried out for the incomplete measurement data. It has been observed that TNNs have performed better than traditional neural networks(NN) in this application and the arithmetic of the TNNs is simple.

Abstract: To solve the problem of sediments on seismic response of concrete dams, pressure wave formula of saturated porous fluid-solid two-phase medium was derived from the Biots consolidation theory, and was determined the seismic response magnitude of sediment on concrete dam. Sediment was regarded as elastic-plasticity. And the method was applied to analyze the influence of sediments density, cohesion and friction angle on dam seismic response. Finally, a typical example is analyzed. The result shows sediments plasticity is relatively obvious on dam seismic response.

Abstract: This paper carries out a numerical simulation of the atmospheric flow field around bridge. The variation law of airflow field around bridge is studied. Velocity and pressure distribution laws of flow field in horizontal plane and the cross-section are discussed, and influence range of flow field around bridge area is identified.

Abstract: The drifting ice sheets impact with the bridge pier and other hydraulic structures in the rivers, which may damage even cause collapse of the structures. In this paper, the FEM software package LS-DYNA was used to performed the numerical simulations of the collision process of the ice sheets and the bridge piers to make clear the interaction between them and to understand the failure mechanism of the ice sheet. The elastic strain-stress model with von mises failure criterion was used to describe the ice material. The brittle damage material model was used to describe the concrete pier. Three types thickness of ice sheets were performed at various velocity of the ice sheet respectively. The impact process of every case were displayed and the time history curve of the collision force were given out. The simulations results show that the peak value of the collision force time history curve increases with the velocity of the sheet firstly and then decreases with the velocity of the ice sheet. There is one critical velocity which relate to the compressive strength of the ice sheet. The simulation result were also compared with the different bridge design code, which show that the code result is more conservative in bridge design.

Abstract: Due to frequent construction of rail traffic system of urbanization, the influence of vibrations caused by urban traffic system on surrounding environment has been increased. China is an ancient country with civilization, which had many unique historical relic resources. Meanwhile, the influence of vibrations by rail transportation system on historical relics had received increasing interest in recent years. This paper proposed a field test method, did a hammer testing in field that we gained vibrations level attenuation quotient with distance variation by the regression method, got velocity attenuation curve with distance variation under the industrial vibrations source which more easier than empirical formula in the standard.