Research On The Wind Load Characteristics Of The Circular Arc Large-Span Cantilevered Roof

The complex-shape large-span roof structures are sensitive to wind loads, but “Load code for the design of building structures”( GB50009-2012) can not provide accurate parameters. So it is significance to researching on the wind load characteristics of the circular arc large-span cantilevered roof.(1) The wind tunnel test was carried out. The rigid model was based on 1/70 scale than the airport terminal which is a circular arc large-span cantilevered roof structure. The test method and process of wind tunnel was introduced in detail. The contour line of the mean and fluctuating wend pressure coefficient under different direction angles were shown, and the shape coefficients of partition were proposed in the paper. The test result show that: the roof cornice bears huge wind pressure in the windward, and it is easy to case damage.(2) Wind flow field numerical simulation is carried out by computational fluid dynamics(CFD) software Fluent 6.3. The ways to select the computational domain, choosing the turbulence model, building the gird, setting the parameter were discussed when the numerical computational was performed. The Stand κ-ε turbulence model, the RNG κ-ε turbulence model and the Realizable κ-ε turbulence model were used to numerical simulation. The numerical simulation of 0o and 180o wind angles were carried out for structure. The simulation results and test results were analyzed on point measuring pressure coefficient,pressure coefficient contours and net shape coefficient. The feasibility and the accuracy of the numerical simulation were verified.(3) The main direction angles on full closed, full opening and openings on the front wall condition were performed numerical simulation. The average wind pressure coefficient contours, wind speed distribution, turbulent kinetic energy distribution and streak line distribution were analyzed. Compared with the test result, we reach the conclusion that: the test result was well reflected by the average wind pressure coefficient contour of simulation results; the differences of wind pressure distribution of the inner surface was been analyzed in several aspects; the wind speed distribution profile directly reflects the wind field around buildings and interior, it is an advantage of numerical simulation.(4) The test and simulation net shape coefficient of the structure was analyzed. The effect of opening in the structure front eave has been discussed. We draw the conclusion that: The wall with openings have small impact on net shape coefficient of roof cornice region; The wind loads on windward roof areas are reduced effectively by making several holes in front eave, especially in the wind direction of oblique. The left and right sides cornice also bearhuge wind loads. The roof cornice especially the corner regions should be reinforced or setting sloping baffles in the cornice below guide the air flow out.