环境温度对钢管混凝土拱桥吊杆振动影响及张力测定研究

Research on vibration properties of suspenders of concrete filled steel tube arch bridges affected by temperature and tension measuring methods

为了提高实际工程中吊杆张力的测试精度,基于Euler-Bernoulli梁理论,考虑外界环境温度变化以及吊杆预应力作用对吊杆振动的影响,建立了变温时吊杆自由振动运动方程,并根据长吊杆边界条件,给出了吊杆张力与温度变化、横向振动频率关系式,分析了吊杆热过屈曲温升条件。采用数值模拟方法与工程实例进行了验证。计算结果显示,环境温度相同时,张力增大吊杆同阶振动频率增大;当张力相同时,环境温度升高,吊杆同阶振动频率降低。对于季节温差较大的地区,吊杆张力测试时环境温度影响不可忽略。考虑温度影响时,关系式计算精度较高,更接近真实值,且方程为显式,实用性强。

In order to improve the calculation accuracy of the suspenders tension in engineering practice,based on the theory of Euler-Bernoulli beam,the free vibration equation of suspender is established,which has considered the influences of outside temperature variations and prestressed of suspender on suspender vibration. The relationship between suspender tension with temperature change and lateral vibration frequency is also given according to the long suspender boundary condition. Then the thermal post-buckling temperature rise conditions of suspenders have been suggested. In order to verify the rightness and feasibility of the theory,numerical simulation method and engineering example are used. The results show that the same order vibration frequency of suspender increases with its tension increasing when the environmental temperature is the same. The same order vibration frequency of suspender decreases with environmental temperature increasing when the tension of suspender is the same. So the environmental temperature can not be ignored when suspender tension is tested in the area where the difference of seasonal temperature is large. The formula has higher accuracy and has more close to the real value when considering the effect of temperature,and it is also explicit and strong practicability.