摘要
分析变温度下实测动应变相关函数幅值向量的变化情况。采用基于主成分分析的环境温度影响剔除方法,寻找主要反映应变时程温度信息的特征子空间。对时程数据重构,得到温度效应成分,由此消除温度对应变信号的影响。研究结果表明:第一主成分反映了动应变时程绝大部分的波动信息;通过第一主成分特征向量可有效提取应变时程中的温度效应成分。基于实测动应变的相关函数幅值向量在各时段的比例形态均存在较大差异,剔除温度效应成分后的相关函数幅值向量呈现一致的比例线形,说明应变时程中的温度效应成分会导致相关函数幅值向量的比例线形发生改变;不考虑环境温度对动应变时程相关函数幅值向量的影响,易对桥梁结构的健康状况产生误判。
Under varying temperature,correlation function amplitude vector of the measured dynamic strain was analyzed.Based on principal component analysis,the method for eliminating the effect of environmental temperature was applied to study the eigenspace reflecting temperature variation.By reconstruction of data,the temperature effect on strain history was eliminated.The results show that the first principal component reflects most of the volatility of data information.With eigenvector of the first principal component,the temperature effect components of strain history are effectively extracted.In different periods,the shape of correlation function amplitude vector(corV) based on measured data is distinct.When temperature effect component is eliminated,the shape of corV performs consistently.The temperature effect component in test data leads to various shapes of corV.Therefore,ignoring the effect of temperature on the corV of strain history is prone to get the false judgment on the real operation condition of structure.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第9期3834-3842,共9页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51078357)
关键词
动应变
相关函数幅值向量
温度影响
主成分分析
dynamic strain
correlation function amplitude vector
temperature effect
principal component analysis
