基于最小二乘法的LabVIEW拟合桥梁挠曲线研究

FBG的测试基本物理量是应变,无法直接测试挠度。但是对于主要承受弯曲的桥梁结构,应变对应着截面弯曲变形的曲率,因此由曲率的大小可以反映弯曲变形的大小。基于该原理,采用最小二乘法由截面的平均曲率分跨拟合桥梁的挠曲线,达到由FBG测试桥梁挠曲线的目的;并通过使用LabVIEW软件编制由曲率拟合挠曲线的专业程序,可以得到任意荷载作用、跨长、支座沉降情况下的挠曲线方程;最后对简支梁在不同荷载作用下的挠曲线进行数值模拟与分析。

Study of LabVIEW Fitting Bridge Deflection Curve Based on Least Square Method

The basic physical quantity tested by FBG is strain,and it is hard to directly test the deflection.However,he strain is corresponding to the curvature of section bending deformation for the bridge structure mainly bearing the bending.Therefore,the value of curvature can reflect the value of bending deformation.Based on this principle,the least square method is used to fit the bridge deflection curve by the spans of average curvature of section so as to achieve the aim of FBG to test the bridge deflection curve,and LabVIEW software is used to compile the special program of deflection curve fit by curvature so as to get the deflection curve equation under the condition of random loading,span length and support settlement.The article numerically simulates and analyzes the deflection curves of simple-supported beam under the different loadings.