Gust Response of a Box Type Stiffening Girder under the Action of Random Wind Force

(1)紊流的主动模拟自然风的模拟是桥面阵风响应风洞研究的一个重要问题。在二维风洞中进行了风湍流的模拟。级联的随机伺服控制可以产生任意给定的湍流。(2)气动导纳的风洞模型试验阵风响应的数值处理需要通过风洞试验来评估气动导纳。得到了桥梁模型随机响应的时间序列。通过时间序列分析随机气动力，得到气动导纳。(3)吊桥阵风响应在23m/s的强风条件下，现场测量了吊桥的阵风响应和风速。(4)悬索桥对阵风荷载的安全性考虑风速和风向的概率，计算了在使用时间内由阵风响应引起的应力循环幅值和次数。对某桥梁构件在阵风荷载作用下的疲劳破坏进行了安全性校核。

(1) ACTIVE SIMULATION OF TURBULENCESimulation of a natural wind is an important problem for a wind tunnel investigation of gust response of a bridge deck. In the two dimensional wind tunnel simulation of wind turbulence was carried out. The random servo-control of a cascade could produce an arbitrary given turbulence.(2) WIND TUNNEL MODEL TESTS FOR AERODYNAMIC ADMITTANCENumerical treatment of a gust response requires an aerodynamic admittance to be assessed through wind tunnel test. Time series of the random response of bridge models were obtained. Through the time series, random aerodynamic force was analyzed and aerodynamic admittance was obtained.(3) GUST RESPONSE OF SUSPENSION BRIDGEThe gust response of the suspension bridge as well as wind speed was measured at the site in a strong wind up to 23m/s.(4) SAFETY OF A SUSPENSION BRIDGE AGAINST GUST LOADThe amplitude and the number of the stress cycles caused by gust response during the service time were calculated considering the probability of wind speed and direction. Safety of a bridge member against gust load was checked concerning fatigue failure.