摘要
建立钢棒拉应力电磁测试系统,进行了拉伸状态的钢棒表面感应电动势测试.通过变频测试方法提取出钢棒应力电学谱纹,并借助最小二乘法得出依据应力--感应电动势谱纹进行应力识别的表达式,分析了应力感应电动势测试机理.结果表明:对于100～600Hz范围内的某一频率值,在拉伸荷载增加过程中,钢棒感应电动势ξ随拉应力σ增加,表现出先增大后减小或一直增大的特征.对于某一固定应力值,感应电动势随着频率增加总体呈下降趋势.随着应力水平的提高,钢棒应力感应电动势谱线逐渐上升.
An induced electromagnetic measuring system of steel bar stress was set up and the electromotive force of the steel bar surface was measured under the condition of tension to find a new way of stress testing. The stress-electrical spectrum lines were obtained by changing measurement frequency, the data were processed and the stress distinguishing was formulated by the method of least squares. The measuring mechanism of stress-electromotive force was analyzed. According to the experimental results, while the tensile stress rising, the change of induced electromotive force shows two kinds of variation characteristics, increasing at the first and then decreasing at the high stress level, or increasing continuously, at a fixed frequency value between 100Hz and 600Hz. The induced electromotive force reduces generally with increasing frequency at a fixed stress value. The stress-electromotive force spectrum lines of steel bars rise with the increment of stress levels.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
2010年第12期1643-1647,共5页
Journal of University of Science and Technology Beijing
基金
国家自然科学基金资助项目(No.50778035)
关键词
钢棒
拉应力
电动势
谱纹
测试
bars
tensile stress
electromotive force
spectrum lines
measurement
