Monitoring of prestress and bond stress of self-sensing FBG steel strand
Monitoring of prestress and bond stress of self-sensing FBG steel strand
复制标题
自感FBG钢绞线预应力和粘结应力监测
DOI：
10.1016/j.measurement.2021.109246
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发表时间：
2021-03-19
期刊：
影响因子：
5.6
通讯作者：
Qin，Heying
中科院分区：
文献类型：
--
作者：
Zhu，Wanxu;Shen，Quanxi;Qin，Heying
为了研究预应力钢绞线中的应力分布以及钢绞线与混凝土之间的粘结应力的发展，提出了一种在钢绞线中心丝纵向凹槽中封装准分布式光纤布拉格光栅（FBG）传感器的新技术。基于FBG传感器与基底之间应变传递的理论分析，讨论了测量FBG传感器稳定性的具体参数。对无粘结预应力活性粉末混凝土梁进行拉伸和弯曲试验，探讨自感知钢绞线特性。测试结果表明，封装在钢绞线中心丝内的准分布式FBG传感器能够有效监测钢绞线内应力分布和梁的损伤情况，最大拉力监测误差仅为3.42%。为了分析钢绞线预应力和粘结应力沿锚固长度的分布情况，对自传感钢绞线进行了拉伸试验。结果表明，准分布式FBG传感器能够准确测量拉伸过程中钢绞线应力和粘结应力沿锚固长度的变化。
In order to investigate the stress distribution in a prestressed steel strand and the development of bond stress between the steel strand and concrete, a new technology of encapsulating quasi-distributed fiber Bragg grating (FBG) sensor in a longitudinal groove of the center wire of a steel strand is proposed. Based on the theoretical analysis of the strain transfer between the FBG sensor and the substrate, specific parameters for measuring the stability of the FBG sensor are discussed. Tension and bending tests on unbonded prestressed reactive powder concrete beams are carried out to explore the self-sensing steel strand characteristics. The test results indicate that the quasi-distributed FBG sensor encapsulated in the center wire of the steel strand can monitor the stress distribution in the steel strand and the damage of the beam efficiently, and the maximum tensile monitoring error is only 3.42%. To analyze the distribution of the prestress and bond stress of steel strand along the anchorage length, the tensile tests are carried out on the self-sensing steel strand. The results show that the quasi-distributed FBG sensor can accurately measure the variations in steel strand stress and bond stress along the anchorage length during the tensile process.