CFRP加固混凝土结构剥离损伤识别试验研究  

PZT-based Debonding Detection of Reinforced Concrete Structure Strengthened with CFRP

作　　者：阎石[1] 马禄哲[1] 

机构地区：[1]沈阳建筑大学土木工程学院,辽宁沈阳110168

出　　处：《土木工程与管理学报》2011年第3期69-74,共6页Journal of Civil Engineering and Management

基　　金：住房与城乡建设部科学技术项目(2008-K4-39);辽宁省高校重点实验室支持计划(2008S189);辽宁省重点实验室开放基金项目(JG-200908)

摘　　要：碳纤维增强复合材料(CFRP)由于强度高、重量轻、适应面广等特点,成为土木工程修复和加固工程中引人注目的替代材料。剥离破坏是CFRP加固结构时常见的破坏方式,一旦发生剥离破坏,将达不到预期的加固效果,不仅造成材料浪费,而且被加固结构也存在安全隐患。可以采用无损检测(NDT)的方法对剥离损伤进行识别。利用压电陶瓷对CFRP加固的混凝土柱的剥离损伤进行试验研究,以确定损伤的位置和程度。将一组压电陶瓷(如镐钛酸铅,简称PZT)预埋在小体积混凝土中,制成"智能骨料",并将其预埋在混凝土柱内的指定位置。柱表面进行CFRP加固处理,在指定位置设置人工模拟剥离损伤。将另一组PZT片粘贴在具有人工剥离损伤处的表面。利用扫频波对具有预先设定剥离区域的CFRP加固混凝土试件进行试验,其中三个预埋的"智能骨料"作为作动器,表面粘贴的PZT作为传感器。对接收到的检测信号,利用傅里叶频谱分析与定义的两个基于小波包分析的损伤指标进行计算,不但成功检测到模拟的剥离区域,而且可以看出损伤指标对试件剥离损伤程度具有足够的灵敏度。Carbon fiber-reinforced polymer（CFRP） composite ma te rial has become an attractive alternate material for rehabilitation and reinforc ement of civil infrastructure systems due to their outstanding strength,light w eight and versatility.Debonding failure is a common failure mode of structure r einforced by the CFRP.Once debonding failure occurs,the desired strengthening effect cannot be reached,resulting in material waste and unsafe for the strengt hened structure.Therefore,a reliable nondestructive testing（NDT） method is re quired to detect the bonding condition.In this paper,the debonding damage for a reinforced concrete column reinforced with CFRP was experimentally researched by using piezoelectric ceramic to determine the damage location and level.A gro up of piezoelectric ceramics（such as Lead Zirconate Titanate,PZT） was embedded into a small volume of concrete to make smart aggregates（SA） which were placed in the given locations in the column.The RC column was strengthened with CFRP and an artificial debonding damage was made by using a piece of plastic cloth be tween the surface of the structure and CFRP.The other group of PZT patches was pasted on the surface of the CFRP at the artificial debonding position.An exper iment for the debonding damage detection was conducted by using sweep sinusoidal wave generated by actuating the SA,and three embedded SAs were used as actuato rs and the surface-bonded PZT patches were applied as sensors.The detecting si gnal was passing through the damage zone and carried the information of the debo nding damage.Based on the Fourier spectra analysis and two defined damage index es based on the wavelet packet analysis on the received signals,the artificiall y mimicked debonding areas were successfully detected and the defined damage ind exes were sensitive enough to the debonding damage in the specimen.

关 键 词：碳纤维增强材料(CFRP) 剥离损伤 损伤识别 压电陶瓷智能骨料 损伤指数 小波包分析 

分 类 号：TM282[一般工业技术—材料科学与工程] TU599[电气工程—电工理论与新技术]