Wind Pressure And Equivalent Static Wind Loads Numerical Simulation On The Typical Large-span Roof Structures

Large-span roofs are rich in model styles and adaptable, could save materials, enhance available space. Therefore they are highly favored by field of architectural design and have a wide range of applications in the airport terminal, galleries, stadiums, industrial plants and other large buildings. However, large-span roofs tend to be light in quality, large in span, great in flexibility, and low in natural frequency, which cause them to be very sensitive to wind loads and wind loads sometimes become their control loads. As a typical random dynamic load, structural dynamic response calculation in wind loads is related to structural dynamics, random vibration, wind load characteristics and the coupling interaction of wind and structures. Wind engineering researchers have proposed the concept of equivalent static wind loads(ESWL) in order to facilitate designers to master design methodology of wind loads. Starting from the wind-resistant problems of large-span structures, this paper describes the wind pressure and wind field simulation methods of large-span structures. The built-on-stilts type disc-shape-like spatial structure is taken as an example, the impact of wind direction, the support column height, the upper and lower span ratio on the disc surface on pressure distribution and wind-induced force were analyzed. For large span roof space, for example, arched steel roof and multi-fold surface roof, the law of pressure distribution the large-span roof was analyzed. The numerical simulation methods of wind loads were summarized in this paper and a computer was programmed based on harmonic superposition method by MATLAB language to simulate the wind speed, which is used as a numerical wind tunnel inlet boundary condition. Then the large-span roofs were calculated in non-steady-state method by FLUENT software to obtaining the dynamic wind loads. Finite element models were established and wind-induced response was calculated. On this basis, single-target equivalent static wind load was got combined with the instantaneous pressure distribution in the structure at the particular time. After that, the concept of multi-objective ESWL factors were defined and equivalent static wind loads are combined based on the load-response correlation coefficient, resulting in multi-target ESWL; Finally, open-span arch roof and folded roof were taken for instance to obtain multi-target ESWL and the dynamic time history analysis results were compared to verify the correctness of the proposed method.