The technology of continuously welded rails (CWRs) is important in modern railway track structures. To measure rail stress, resistance strain gauges are preferred due to their good stability, sensitivity, and resistance to external interference. Based on the bi-directional strain method, we present a new method for measuring longitudinal rail stress using resistance strain gauges and develop a monitoring device for rail stress to realize long-term and multi-point measurement. Also relevant experimental verification and analysis are conducted. Results indicate that under various constraints the rail stress–strain values can be calculated just with the measured total longitudinal strain and total vertical strain. Considering the measurement error caused by sectional feature of sensors, we put forward a correction equation applicable to different stress conditions. Although the temperature values of the four full-bridge stress gauges can offset each other, the measurement error caused by rail flexural strain can also be eliminated to a certain extent at the same time, the non-uniform distribution of rail cross section temperature and unbalanced flexural strain still affect the measurement error. The experimental results also show that the developed rail-stress-monitoring sensor is suitable for measuring rail stress with reliable working performance.

中文翻译：

---

一种采用双向应变法监测连续焊接钢轨应力的新装置

连续焊接钢轨（CWR）技术在现代铁路轨道结构中很重要。为了测量钢轨应力，首选电阻应变仪，因为它们具有良好的稳定性，灵敏度和耐外部干扰性。在双向应变方法的基础上，提出了一种利用电阻应变仪测量钢轨纵向应力的新方法，并开发了钢轨应力监测装置，实现了长期多点测量。还进行了相关的实验验证和分析。结果表明，在各种约束条件下，仅通过测得的总纵向应变和总垂直应变就可以计算出钢轨的应力-应变值。考虑到传感器的截面特征引起的测量误差，我们提出了适用于不同应力条件的校正方程。尽管四个全桥应力计的温度值可以相互抵消，但同时也可以在一定程度上消除由钢轨弯曲应变引起的测量误差，钢轨横截面温度分布不均匀和不平衡。弯曲应变仍会影响测量误差。实验结果还表明，所开发的轨道应力监测传感器适用于测量轨道应力，具有可靠的工作性能。钢轨截面温度的不均匀分布和弯曲应变的不平衡仍会影响测量误差。实验结果还表明，所开发的轨道应力监测传感器适用于测量轨道应力，具有可靠的工作性能。钢轨截面温度的不均匀分布和弯曲应变的不平衡仍会影响测量误差。实验结果还表明，所开发的轨道应力监测传感器适用于测量轨道应力，具有可靠的工作性能。