基于连续碳纤维/树脂智能材料的梁结构应变模态表征  

Strain modal characterization of beams using continuous carbon fiber/polymer smart composite

作　　者：朱四荣[1] 周志勇[1] 吕泳[1] 郑华升[1] 李卓球[1] 

机构地区：[1]武汉理工大学理学院,武汉430070

出　　处：《复合材料学报》2013年第3期240-246,共7页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(50878169)

摘　　要：研制了一种具有动态传感功能的碳纤维/树脂智能层,可用于结构的应变模态诊断。通过不同加载频率下的单向拉伸实验揭示了这种智能材料对低频动态载荷的响应能力,并理论分析了动态响应误差的影响因素。在此基础上将碳纤维/环氧树脂智能层连续敷设于悬臂梁结构表面代替传统的点式应变片,进行应变模态测试。测试结果表明,碳纤维/环氧树脂智能层可以较精确地反映结构的前三阶固有频率,并较好地表征结构的前三阶应变模态振型。对悬臂梁局部附加质量后重新进行了模态试验,结果表明:附加质量后,智能层反映的结构固有频率显著下降;同时,在附加质量所在的节点位置,智能层反映的应变模态振型有突变产生,说明智能层所表征的应变模态对结构物性参数变化具有识别能力,采用智能层与采用应变片的实验结果一致。此外,基于碳纤维/树脂智能层的可覆盖性,采用有限的测点全面捕捉了结构的应变模态信息,并在测试中通过在可疑区域内逐步增加测点,实现了结构物性参数变化的定位。A carbon fiber/polymer smart layer able to sense dynamic strain was developed to perform structural strain modal diagnosis. The sensitivity of such a smart material to dynamic load at low frequency was revealed by the tension tests conducted with different frequencies, and the influencing factors on the error of the dynamic response were analyzed theoretically. The smart layer was continuously laid on a cantilever beam and took place of traditional strain gauges to test its strain modals. The test results indicate that the smart layer is able to exactly present the natural frequencies and the strain modal shapes of the first three orders for the beam. The test was conducted again on the beam with added mass. It is found that the added mass leads to the decrease of the natural frequencies and induces mutations on the smart layer characterized strain modal just in the position where the mass added. The results demonstrate the ability of the smart layer characterized strain modal to identify the change of the structural physical parameters. Good agreement was achieved between the results attained with the smart layer and the strain gauges. In addition, based on the ability of covering in smart layer, the information about the structural strain modal is fully captured. Furthermore, the change of the structural physical parameters is located by the tests with added measured points in the suspected area.

关 键 词：碳纤维 树脂智能层 动态传感特性 结构健康监测 应变模态 物性参数变化识别 

分 类 号：TB332[一般工业技术—材料科学与工程]