Study On Wind Load Characteristics Of Lattice Transmission Line

With the great development of China's economy and society, our country will be more and more demand for energy. Because of its advantages of convenient transportation and cleaning, the electric power has been used in all aspects of our production and life. As the reason of the popularity of electric power and its correlation with our life, ensuring its safe and smooth operation is our priority among priorities. One of the most important threat to the electric safe operation is the damage of transmission structure due to wind, snow storms, earthquakes and other natural disasters. And this paper basing on this, research the wind load characteristics of power grid structure through the method of wind tunnel tests, theoretical analysis, numerical simulation and finite element calculation and so on, obtained some useful conclusions. Now the main research contents of this paper are listed as follows:(1) The shape factor test of transmission tower. Through the wind tunnel test of triangle angle steel tower and steel tube and angle steel combination tower, the triangular tower shape factor of variation were obtained. The triangle angle steel tower's values of the wind tunnel tests and the current code values are compared and the test values are 11% higher than the values of Load code for the design of building structures. The code values are not safe. Finally put forward a method on steel pipe and angle steel tower combination of wind load shape factor. Make up for the deficiencies of shape factor in current standard in this kind of structure.(2) The whole combined substation framework shape factor test. Through the wind tunnel test of the whole combined substation framework, the interference coefficient of the beam at different position is obtained. On the basis of the results of single beam shape factor and the interference coefficient of the beam at different positions, we can get the final shape factors of the beams by multipling the two values.(3) The wind induced vibration response analysis of whole combined substation framework. According to the principle of harmonic synthesis method, we simulated the fluctuating wind speed process of the whole combined substation framework. According to the data of fluctuating wind speed process, we took the time domain analysis to the whole combined substation framework by establishment of the finite element model and calculated the wind vibration response in different damping ratio and different constraint conditions. Through the comparison of typical position structure results, introduce some main factors which have significant influence on the wind vibration of the structure.(4) Dynamic response factor analysis of whole combined substation framework. In the foundation of wind induced vibration response analysis of whole combined substation framework and according to the gust loading factor method proposed by Davenport, we calculated the dynamic response factor by drawing up the MATLAB program, and researched the effects on the dynamic response factor under different damping ratios and different forms of support restraint. Comparing the calculated results with the standard value of dynamic response factor, found that the values of Code for design of high-rising structures and Load code for the design of building structures(according to high-rising structures) are too conservative. Values are large 10% than the calculated results and even the maximum deviation is almost 37%. The calculated value is close to the value of Technical code for design of substation buildings and structures, and its changes regular along the height direction is also consistent.