Patent ID: 11946923
Assignee: QINGDAO UNIVERSITY OF TECHNOLOGY
Field: Measurement (Instruments)
Classification: CPC G  E | IPC E  G

Claim 5:
6. A method for monitoring freezing-thawing damage of an underwater concrete member in situ, wherein a process comprises:
I, launching of a probe comprising: when a wireless temperature sensor detects a water temperature higher than 0° C. near a concrete member, uploading the water temperature to a computer, turning on, by the computer, a wireless switch #2, so that an electromagnet is energized and generates magnetism, an iron block is attracted to the electromagnet, a steel plate bracket is moved leftward, and a spring set is compressed, and turning off, by the computer, the wireless switch #2, so that the electromagnet is demagnetized, the iron block is released, the spring set is restored to an original shape while driving the steel plate bracket to move rightward, and a repulsive force is generated between a magnet #1 and a magnet #2 and pushes a launching guide rod out, so that a probe impacts the concrete member;
II collection of data comprising: acquiring, after the probe impacts the concrete member, data such as a speed at which the probe impacts the concrete member and a duration of the impact, transmitting the data to a multichannel data collector and then to the computer by using a frequency modulation transmitter, turning on, by the computer, a wireless switch #1, so that a submersible motor drives a primary pulley to rotate, a reel collects a transmission chain transmitted by the primary pulley, and the transmission chain drives a probe launching box to move upward by using a secondary pulley, repeating step I such that the probe impacts different positions of the concrete member, and transmitting data acquired by the probe to the computer, wherein
when the reel releases the transmission chain, the secondary pulley drives the probe launching box to move downward, and a movable guide rod is moved between two columns of auxiliary wheels during the upward and downward movement of the probe launching box, to guide and stably maintain the upward and downward movement of the probe launching box;
III, calculation of an elastic modulus comprising: calculating, by the computer, an elastic modulus of the concrete member in real time according to the data transmitted by the frequency modulation transmitter and an elastic modulus calculation equation, drawing a variation curve of the elastic modulus of the concrete member in real time by using Matlab and Origin, and analyzing a law of the elastic modulus varying with time; and
IV, evaluation of freezing-thawing damage comprising: evaluating the freezing-thawing damage of the concrete member according to the elastic modulus of the concrete member, the variation curve of the elastic modulus, and the law of the elastic modulus varying with time that are obtained in step III, and determining that the concrete member has been subjected to freezing-thawing damage when a loss rate of the elastic modulus reaches 60%.