悬索桥索股下料长度求解方法及其影响因素分析

Method and impacting factors analysis in computing fabrication length of suspension bridge's main cable strand

采用基于通用有限元软件ANSYS的二次开发语言APDL编程实现悬索桥主缆索股无应力索长的自动化求解,程序中根据中心索股空间坐标建立局部坐标系,在此坐标系内建立其他索股相对于中心索股的排列,建立主缆各索股各关键点之间的真实空间模型,考虑索鞍处的圆曲线修正,提取单元长度,得到各索股的真实索长.算例表明:恒载集度、控制点坐标误差、温度是主要影响因素,其他因素影响较小;同一索股内钢丝长度差值最大为6.75cm.结果表明该方法计算精确、使用方便,应用于空间索面自锚式悬索桥等复杂结构的主缆无应力长度的求解工作时能有效减少工作量.

The automatic computation of non-stress length of the main cable strand of suspension bridge was implemented by programs developed by the second development language APLD of FEA commercials ANSYS. The local coordinates was established according to the central strand＇s spatial coordinates, and then the array of other strands relative to the central strand in the local coordinates was set up. Finally, the real spatial model between the key points of each strand in the main cable was built, which took into account the correction between line and circle at saddles, and then the real length of strand was got by picking-up all element＇s length. An example indicates that the crucial impacting factors include dead load, coordinates error of control points and temperature, and other factors＇ impact is small. The maximum length difference of steel wires in one strand is 6. 75 cm. The result shows that this method is accurate and simple, and can be applied to complex structure such as the spatial cable net self-anchored suspension bridge to decrease job.