Earthquake action is multi-dimensional and random. Under bidirectional horizontal direction loading, the seismic capability of beam-column joints in reinforced concrete (RC) frame may be lower than the design capabili...
Earthquake action is multi-dimensional and random. Under bidirectional horizontal direction loading, the seismic capability of beam-column joints in reinforced concrete (RC) frame may be lower than the design capability under unidirectional main direction loading. Detailed calculation methods for the shear bearing capability and shearing performance of RC space joints in frames under bidirectional horizontal direction loading have not been reported. In this work, the shear mechanism and internal force calculation method of an RC space joint under bidirectional horizontal direction loading are analyzed. Furthermore, a shear capacity calculation model is established based on the strut-and-tie model. The prediction of the shear capability in this work are in good agreement with the reported experimental results. This study provides a design method for the seismic design of RC space frame joints, and provides a supplement for the seismic design method of RC space frame with 'strong joints and weak members', when they are subjected to bidirectional horizontal direction loading at the same time.
In order to promote fire resistance of bolts connections, this paper developed an experimental program for investigating mechanical properties of stainless bolts at elevated temperatures, in which standard coupon spec...
详细信息
Based on the principle of coordinate transformation, a mathematical model of induction motors in the three-phase stationary coordinate system was transformed to that in the synchronous rotating coordinate system. For ...
Based on the principle of coordinate transformation, a mathematical model of induction motors in the three-phase stationary coordinate system was transformed to that in the synchronous rotating coordinate system. For motors with low-speed rotors, the multi-variable, high-order, strong-coupling and nonlinear equation of motors was further transformed to a linear equation. However, it was found difficult to solve the deduced linear equation through the method of least squares due to its high singularity. The steady-state stator resistance could be predetermined by temperature revision on the stator resistant in the motor nameplate. Identification of four motor parameters (Ls ,M, Rr , Lr ) was followed by the recursive least-squares method. Simulations of motor parameter estimation were carried out in Simulink of Matlab. The recursive least-squares method was used to deal with the measured data. The results demonstrate that the real-time electrical parameters (Ls , σ, Tr ) can be accurately predicted. Given the assumption of Ls = Lr in the classical motor theory, the other three electrical parameters (M, Rr , Lr ) can also be identified. The identification of these parameters is of great importance for the analysis, control and fault diagnosis of induction motors.
Lightweight geomaterial（LWGM）possesses such merit characteristics as low unit weight,environmental protection（recycling these materials instead of stockpiling them）,buffering mechanical property and thermal insula...
详细信息
Lightweight geomaterial（LWGM）possesses such merit characteristics as low unit weight,environmental protection（recycling these materials instead of stockpiling them）,buffering mechanical property and thermal insulation[1].LWGM,an attractive substitute for earth fills,
The most well-known traditional approach to deal with the uncertainties of the activity durations in a project was the Project Evaluation and Review Technique (PERT). However, traditional PERT is not widely adopted in...
详细信息
Fifteen temperature indices recommended by the ETCCDI (Expert Team on Climate Change Detection and Indices) were applied to evaluate spatiotemporal variability and trends in annual intensity, frequency, and duration o...
Fifteen temperature indices recommended by the ETCCDI (Expert Team on Climate Change Detection and Indices) were applied to evaluate spatiotemporal variability and trends in annual intensity, frequency, and duration of extreme temperature statistics in Finland during 1961–2011. Statistically significant relationships between these high-resolution (10 km) temperature indices and seven influential Northern Hemisphere teleconnection patterns (NHTPs) for the interannual climate variability were also identified. During the study period (1961–2011), warming trends in extreme temperatures were generally manifested by statistically significant increases in cold temperature extremes rather than in the warm temperature extremes. As expected, warm days and nights became more frequent, while fewer cold days and nights occurred. The frequency of frost and icing days also decreased. Finland experienced more (less) frequent warm (cold) temperature extremes over the past few decades. Significant lengthening in warm spells was observed in Finland during 1961–2011, while no clear changes are found in cold spells. Interannual variations in the temperature indices were significantly associated with a number of NHTPs. In general, warm temperature extremes show significant correlations with the East Atlantic and the Scandinavia patterns and cold temperature extremes with the Arctic Oscillation and the North Atlantic Oscillation patterns.
As the key node of the entire transportation network, improving the management level of multimodal passenger transportation hub and to prevent group security incidents, it is necessary to carry out dynamic forecasting...
详细信息
This paper describes bi-directional pseudo-dynamic tests of an eight-storey buckling-restrained braced (BRB) reinforced concrete (RC) frame (BRB-RCF) building. In the test, the bottom two storeys were full-scale exper...
详细信息
The combined system of Radiant Chilled Ceilings and Displacement Ventilation (RC/DV) system represent a promising integrated technology that can meet the requirements for both energy efficiency and thermal comfort. As...
详细信息
The combined system of Radiant Chilled Ceilings and Displacement Ventilation (RC/DV) system represent a promising integrated technology that can meet the requirements for both energy efficiency and thermal comfort. As a result, RC/DV systems have gained much more attention and used widely in advanced buildings in recent years. However, the radiant cooling surfaces influence the heat exchange within a room, the characteristics of the indoor thermal environment still need to be studied. In this paper, an office room with combined system was established and the flow and temperature fields were simulated by Computational Fluid Dynamitic (CFD) method. During the simulation process, 7 cases were compared to investigate the impacts of radiant cooling surface layout on thermal environment. The displacement ventilation system and its operating conditions of each case is identical. All the radiant cooling surfaces have the same surface temperature and the total cooling surface area of case is 17.8m
2
. The results show lower room temperature and better thermal comfort were achieved on cases with radiant cooling surface configured to the upper part of the room.
暂无评论