摘要
桥梁结构在运营过程中由于车辆荷载作用和自身存在损伤的情况下都将引起结构动力特性的变化。文章采用瑞利-里兹法,提出了多跨连续桥梁位移试函数的一般表达式,以契比雪夫多项式为级数函数,计算了结构三阶自振频率,通过与ANSYS有限元结果进行了详细的比较分析,检查了所提方法的准确性。从而推广计算了多跨连续梁桥在通行车辆下的有载频率,对车辆、损伤引起的结构频率变化分别进行了定量分析。模拟计算结果表明:连续梁桥在模拟的车载作用下,振动频率最大可以发生接近7%的变化,大于模拟损伤状况下因损伤引起的自振频率变化。
The dynamic property of a bridge under routine traffic conditions is variable due to vehicle loads and damage. In this paper, firstly, a general formula of displacement functions for a continuous beam bridge is presented, and the lower approximate natural frequencies are studied with Chebyshev polynomial being a series function on the basis of Rayleigh-Ritz method. Then According to comparison between the above approximate solutions and FE solution of ANSYS soft, the proposed displacement function is correct. Finally, it is applied to calculating the loaded natural frequencies in order to analyze change of vibration frequencies caused by vehi- cles and damage. It is shown by a numerical example that the vibration frequencies of 3rd modes for a bridge affected by vehicles loads vary within about 7%, which is higher than varieties of natural frequencies caused by simulated damage.
出处
《江苏建筑》
2010年第1期31-33,共3页
Jiangsu Construction
关键词
连续梁桥
有载频率
瑞利-里兹法
自振频率
契比雪夫多项式
continuous beam bridge
loaded natural frequency
rayleigh-ritz method
natural frequency
chebyshev polynomial
