Chaki S, Bourse G
Ecole des Mines de Douai, Département Technologie des Polymères et Composite et Ingénierie Mécanique (TPC & IM), Douai Cedex, France.
Ultrasonics. 2009 Feb;49(2):162-71. doi: 10.1016/j.ultras.2008.07.009. Epub 2008 Jul 27.
The safety of prestressed civil structures such as bridges, dams, nuclear power plants, etc. directly involves the security of both environment and users. Health monitoring of the tensioning components, such as strands, tendons, bars, anchorage bolts, etc. is an important research topic and a challenging task bringing together the non-destructive evaluation (NDE) and civil engineering communities. This paper deals with a guided ultrasonic wave procedure for monitoring the stress levels in seven-wire steel strands (15.7 mm in diameter). The mechanical and geometrical characteristics of the prestressed strands were taken into account for optimizing the measurement configuration and then the choice of the guided ultrasonic mode at a suitable frequency. Simplified acoustoelastic formulations were derived from the acoustoelasticity theory according to either calibration test or in situ measurement. The results from acoustoelastic measurements on the seven-wire steel strands are presented and discussed in the case of calibration tests and industrially prestressed strands. They show the potential and the suitability of the proposed guided wave method for evaluating the stress levels in the tested seven-wire steel strands.
桥梁、大坝、核电站等预应力土木结构的安全性直接关系到环境和使用者的安全。对钢绞线、锚索、钢筋、地脚螺栓等张拉部件进行健康监测是一个重要的研究课题，也是一项极具挑战性的任务，它将无损检测（NDE）和土木工程领域结合在一起。本文探讨了一种用于监测直径为15.7毫米的七丝钢绞线应力水平的导波超声检测方法。考虑到预应力钢绞线的力学和几何特性，优化了测量配置，进而选择了合适频率下的导波模式。根据校准试验或现场测量，从声弹性理论推导出简化的声弹性公式。介绍并讨论了在校准试验和工业预应力钢绞线情况下，七丝钢绞线声弹性测量的结果。结果表明，所提出的导波方法在评估被测七丝钢绞线应力水平方面具有潜力和适用性。
