Wind Load Characteristics And Wind-induced Response Analysis Of Open Half-moon Arched Large-span Roof

Large-span roofs often have the characteristics of lighter weight,lower damping,and lower frequency.They are wind-sensitive structures.The wind-resistant design of such buildings has become an indispensable link.Although many researchers at home and abroad have conducted corresponding wind load studies on long-span building structures,there are not uncommon examples of wind loads causing overall building collapse or partial damage during natural disasters each year.At present,many studies have formed relatively systematic theories on large-span structures,and they are only aimed at relatively simple structures.For open halfmoon arched large-span roof structures,domestic and foreign codes have not addressed such large-span roof structures.The roof wind load and wind-vibration coefficient have made corresponding design recommendations,and a systematic and mature theoretical system has not yet been formed.Therefore,this paper analyzes the wind load characteristics and windinduced response of the open long-span roof structure based on the rigid model wind tunnel test.The work and conclusions of this paper are as follows:(1)The wind tunnel test of the rigid model with or without openings was carried out on the wind-sensitive areas of the large-span roof structure successively,and the most unfavorable wind direction angles of 30° and 60° before and after the roof opening and the 90° wind direction with large negative pressure were studied.The change of the body shape coefficient of each sub-area of the roof under the corner,especially the change of the body shape coefficient of the area near the opening.In order to further study the force mechanism of the roof structure,the wind loads on the upper and lower surfaces of the roof before and after the opening are also analyzed.Studies have shown that: at 30°,60°,and 90° wind direction angles,the airflow is in the direction of the opposite slope,and the separation effect of the airflow on the windward is greater,so the maximum value of the negative wind pressure coefficient appears on the upper surface of the roof.The front edge of the windward position,and the lower surface of the roof is blocked by the lower stand structure,which accelerates the flow of airflow and inhibits the separation of the airflow on the roof surface,making the lower surface present a smaller positive pressure.After the roof is opened in the wind load sensitive area,it will weaken the wind pressure at the front edge of the wind,and the maximum reduction rate is 53.5%.(2)Based on the wind tunnel test time history data,the probability density distribution of the wind load on the roof surface before and after the opening,the correlation of the wind load on the upper and lower surfaces of the roof,the measurement points parallel to the direction of the incoming flow,and perpendicular to the direction of the incoming flow The correlation between the wind load and the peak factor and the extreme value of negative wind pressure are analyzed,and the non-Gaussian area classification standard is given.The research results show that the non-Gaussian wind load of the open large-span roof is mainly concentrated on the windward front edge,which is due to the influence of the bluff body effect,which makes the non-Gaussian pulse signal strong at this location.Comparing and analyzing the crest factor and negative value wind pressure before and after the opening,it can be seen that the crest factor at the upwind front edge position increases after the roof opening,while the negative value wind pressure decreases,which is distributed near the roof opening in the middle span The extreme value of the negative wind pressure at the measuring point is significantly reduced.(3)According to the wind tunnel test data of the rigid model,the finite element model of the open large-span stadium roof was established,and the simulation model was used to calculate the wind-induced response time history with the ANSYS finite element software,mainly for three wind directions The vertical displacement mean value,displacement root mean square and acceleration root mean square of the roof under the corner with or without openings are analyzed.Research shows that opening holes in the wind-sensitive area of a large-span roof can not only reduce the wind pressure on the roof surface,but also reduce the mean displacement,the root mean square of displacement and the root mean square of acceleration;but the root mean square of displacement and acceleration are both The reduction effect of the square root is not as significant as the displacement mean effect.Therefore,opening holes in the wind-sensitive area of the roof reduces the wind load and wind-induced response to varying degrees,which is beneficial to the structure.