TITLE:
Deflection Measurement for Bridges Based on Secant Inclination
AUTHORS:
Yi Wu, Jing Li
KEYWORDS:
Bridge, Deflection, Inclination, Secant, Measurement
JOURNAL NAME:
Open Journal of Civil Engineering,
Vol.11 No.4,
December
23,
2021
ABSTRACT: Deflection
is a significant indicator of bridge’s strength and its whole stiffness, so the
research on deflection measurement is an important aspect of bridge health
monitoring. There have existed many measurement methods of bridge deflection so
far, while inclination method is gradually catching more and more attention for
its fair obviously comprehensive advantages. However, the inclination method at
present focuses on measuring the rotation of bridge’s section at testing point,
that is, the tangent angle of deflection curve. With the tangent angle, the
deflection curve can be determined by the methods of curve fitting or (and)
integration or conjugate beam. The methods mentioned above, are not only
complicated in calculation, but also bad in accuracy. The deflection
measurement method proposed by this paper is based on measuring the inclination
of two points initiatively in horizontal line, that is, the secant angle of the
deflection curve, and on the simple triangle function operation. The proposed
method is simple in theory, but good in accuracy for either static or dynamic
load. The numerical simulation suggests that the error of the proposed method
is less than 1%.