Rain-wind-induced Dynamic Response Analysis And Wind Tunnel Experiment Of High-Voltage Transmission Tower

In recent years, with the rapid development of the national economy, science technology and environmental awareness, the power industry which is an economic construction and people's pillar industries are undergoing tremendous changes, high-voltage transmission towers as the backbone of power transmission, and its safety can be dependent much attention. Transmission tower have high tower structure, long span, the overall structural flexibility strong, and both high-rise tower structures and common characteristics of long-span structures, the wind is the main control load. Due to the strong wind and rain effect on the transmission tower, the damage and disaster is frequently occurring.In this paper, high-voltage transmission towers as a research vehicle, which use of wind load simulations carried out on the high-voltage transmission tower wind excitation dynamic response analysis, and produced aeroelastic model for the wind (rain) Response wind tunnel tests. Specifically addressed the following areas:(1) We summarize the basic wind load, including the basic characteristics of the wind, wind speed and pressure of the conversion relationships and the role of wind on structures. Describes the simulation of wind loads, mainly discussed the simulation of fluctuating wind load. Harmonic superposition method using the time history of wind load was simulated for the actual situation in power transmission tower, the wind load model for the establishment. Then, introducing the rain load simulation, including the basic concepts of rainfall, rainfall intensity concept, the classification of rain, the concept of raindrop size distribution, distribution of raindrops, and analyzes the impact of raindrops.(2) The analysis of the model using the finite element software SAP2000, and lists the transmission tower natural frequency table and the vibration mode diagram. The simulation for the transmission tower of the wind load time history, which use the simulation of wind loads and loads of rain simulation method in the second chapter. Dynamic response analysis was carried under a single wind load and wind and rain loads, which using the above simulated wind load time history.(3) Describes the modeling of the similarity theory, which is prerequisite for modeling and key basis. Introduced the method of model design and model of the processing methods. Using hollow brass tube to simulate the stiffness of the tower, using lightweight ABS board to simulate coat. We measured the model after aeroelastic modeling completed. Put the small coat acceleration sensor in the transmission tower model, and a free model of excitation method to measure acceleration time history obtained, and then use FFT processing of the data obtained from the vibration frequency.(4) Describes the content of wind tunnel tests. Introduced similar ratio of wind and rain loads, which provides a theoretical basic method for the wind tunnel test of transmission tower. Transmission tower and the cross-wind response of wind-induced vibration response of along wind considerable can not be ignored in structural design of wind-induced vibration response of cross-wind contribution. As the rainfall intensity, wind and rain induced vibration has a tendency to increase, the percentage increase of 5%-20%, which also shows the load can not ignore the impact of the rain.