摘要
采用单模光纤和基于差分脉冲对(DPP)技术的布里渊光时域分析仪(BOTDA)对表面已有2条宽度分别为0.5和0.1mm、间距20cm裂缝的钢筋混凝土梁在一定荷载下裂缝的扩展变化进行了试验研究.将一根直径250μm的裸光纤环绕4道跨过相同裂缝,并采用不同的胶黏剂全面黏接,研究了胶黏剂粘贴效果对测量结果的影响.在梁中部加载10kN的静态荷载使裂缝扩展,将BOTDA的空间分辨率设为5cm,采样间隔设为1cm,经初步的信号处理,即可获得混凝土表面裂缝扩展的应变分布的明显变化.测量结果表明,具有高空间分辨率和较小空间采样间隔的DPP-BOTDA能比较准确地测量混凝土连续梁表面比较密集的裂缝受压扩展情况,测量结果基本不受胶黏剂的影响.
Using single-mode fiber（SMF）and Brillouin optical time-domain analyzer（BOTDA）,we test and study the multi-crack propagation at a certain load on the surface of a reinforced concrete beam which embodies two existing cracks.The width of two cracks measures 0.5 mm and 0.1 mm,respectively,and the spacing is 20 cm.Encircling the bare fiber with the diameter of 250μm four times across the same crack,and sticking with different adhesive,we conduct a comprehensive study of the impact of the paste effect on measurement results.We place a 10 kN static load on the middle of the beam to activate the propagation of cracks,while set-ting the spatial-resolution and sampling-interval of the BOTDA with 5 cm and 1 cm,respectively.Measurement results show that the BOTDA with high spatial-resolution and a smaller sampling interval can more accurately measure the strain distribution of closely spaced cracks under different degrees of propagation,reflect the propagation situation of intensive cracks on the continuous concrete beam.In other words,measurement results are basically unaffected by different adhesives.
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2016年第4期596-600,共5页
Journal of Xiamen University：Natural Science
基金
国家质检总局2014年科技计划项目(2014IK199)
福建省科技计划项目(2014H6027)
厦门市科技项目(3502Z20141049)
