应用磁通量传感器监测体内预应力研究

体内预应力筋位于预应力混凝土结构的内部，无论是施工还是服役阶段，往往很难对其隐蔽曲段进行检查。由于管道摩擦、锚具回缩、混凝土的瞬时压缩和长期收缩与徐变以及预应力筋松弛等原因，体内预应力不可避免发生预应力损失。预应力损失后，对预应力进行监测，确定永存预应力极其重要。磁通量传感器是基于铁磁性材料的磁弹效应原理制成的，该种测量方法直接监测构件状态，属于无损与非接触性测量方法，传感器安装方便且长期稳定性好。本文研究将磁通量传感器应用于体内预应力筋监测，对传感器的测量原理、传感性能、温度补偿、预应力筋松弛和疲劳影响、测试环境影响以及工程案例等进行了详细的研究，研究结果表明磁通量传感器是监测体内预应力的一种有效方法。

Study on monitoring internal prestress by magnetic flux sensor

The internal prestressed reinforcement is located in the interior of the prestressed concrete structure, and it is often difficult to inspect the hidden bend of the prestressed concrete structure no matter in the construction or service stage. Due to pipeline friction, anchorage retraction, instantaneous compression and long-term shrinkage and creep of concrete, and relaxation of prestressed tendons, the internal prestressed stress loss is inevitable. After the loss of prestress, it is very important to monitor the prestress and determine the permanent prestress. Magnetic flux sensor is made based on the principle of magnetoelastic effect of ferromagnetic materials. This measurement method directly monitors the state of components, which is a non-destructive and non-contact measurement method, and the sensor is easy to install and has good long-term stability. In this paper, the magnetic flux sensor is applied to the monitoring of internal prestressed tendons. The measurement principle, sensing performance, temperature compensation, relaxation and fatigue of prestressed tendons, test environment and engineering cases of the sensor are studied in detail. The research results show that the magnetic flux sensor is an effective method to monitor internal prestressed tendons.