System for monitoring tension force of tendon in post-tensioning

Patent metadata

Field	Value
Publication number	US-10844619-B2
Application number	US-201816119714-A
Country	US
Kind code	B2
Filing date	Aug 31, 2018
Priority date	Jul 29, 2015
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

A system for monitoring tension forces of tendons disposed inside a concrete structure in post-tensioning includes a hydraulic jack coupled to one tendon at one end of the concrete structure to apply the tension force to the tendon by means of the forward movement of a piston; a hydraulic pump connected to the hydraulic jack by means of a hydraulic pressure supply pipe to supply a hydraulic pressure to the hydraulic jack; a digital elongation length measurement sensor disposed on the hydraulic jack to measure the elongation length of the piston; a measurement unit having a data logger adapted to receive and store the elongation length data measured by the digital elongation length measurement sensor and to send the elongation length data to a main server; a digital pressure measurement sensor disposed on the hydraulic pressure supply pipe of the hydraulic pump; and a control module adapted to receive the elongation length data from the data logger or the main server, calculate the tension force, compensate for the coefficient of elasticity of the tendon according to the ratio of the real-time elongation length data to the pressure data, and compensate for the tension force calculated.

First claim

What is claimed is:

1. A system for monitoring tension forces of tendons disposed inside a structure in post-tensioning, the system comprising:
a jack coupled to one tendon at one end to apply a tension force to the tendon, the jack including a movable piston;
a pump connected to the jack via a pressure supply conduit to supply a pressurized fluid to the jack;
a displacement sensor configured to measure a real-time position of the movable piston;
a pressure sensor configured to measure a real-time pressure of the pressurized fluid in the pressure supply conduit;
a data logging memory configured to receive and store real-time data and to transmit the real-time data to a main server, the real-time data including at least one of the real-time position of the movable piston as measured by the displacement sensor and the real-time pressure of the pressurized fluid as measured by the pressure sensor;
a control module configured to receive the real-time data from the data logging memory or the main server to modify a flow output of the pump; and
a position sensor disposed on the jack to measure a displacement of a reference point marked on an outer surface of the tendon after the control module controls the pump to stop supplying the pressurized fluid to the jack, the displacement of the reference point being used to compensate for a stop point of the movable piston in the verified tension force of the tendon,
wherein the control module is further configured to:
receive the real-time pressure of the pressurized fluid from the data logging memory or the main server, and
calculate the tension force of the tendon using the real-time pressure of the pressurized fluid to verify the tension force calculated using the real-time position of the movable piston.

2. The system according to claim 1 , wherein if the real-time pressure of the pressurized fluid measured by the pressure sensor reaches a predetermined value, the control module stops the pump from supplying the pressurized fluid to the jack.

3. A system for monitoring tension forces of tendons disposed inside a structure in post-tensioning, the system comprising:
a jack coupled to one tendon at one end to apply a tension force to the tendon, the jack including a movable piston;
a pump connected to the jack via a pressure supply conduit to supply a pressurized fluid to the jack;
a displacement sensor configured to measure a real-time position of the movable piston;
a pressure sensor configured to measure a real-time pressure of the pressurized fluid in the pressure supply conduit;
a data logging memory configured to receive and store real-time data and to transmit the real-time data to a main server, the real-time data including at least one of the real-time position of the movable piston as measured by the displacement sensor and the real-time pressure of the pressurized fluid as measured by the pressure sensor;
a control module configured to modify a flow output of the pump based on to the real-time data; and
a near field communication module coupled to the data logging memory configured to transmit the real-time data to a mobile terminal, wherein the mobile terminal is configured to transmit the received real-time data to the main server,
wherein the main server is configured to classify, calculate, and output the real-time data and to calculate a maximum error rate and a mean value of the real-time data.

4. A system including a jack with a movable piston coupled to one end of a tendon and a pump connected to the jack via a pressure supply conduit to supply a pressurized fluid to the jack to apply a tension force to the tendon, the system being configured to monitor the tension force of tendon disposed inside a structure in post-tensioning, the system comprising:
a displacement sensor configured to measure a real-time position of the movable piston;
a pressure sensor configured to measure a real-time pressure of the pressurized fluid in the pressure supply conduit;
a data logging memory configured to receive and store real-time data and to transmit the real-time data to a main server, the real-time data including at least one of the real-time position of the movable piston as measured by the displacement sensor and the real-time pressure of the pressurized fluid as measured by the pressure sensor; and
a control module configured to modify a flow output of the pump based on to the real-time data,
wherein the data logging memory is in electrical communication with the main server via a wireless or a wired network, the main server including a database for storing the real-time data transmitted from the data logging memory.

5. A system including a jack with a movable piston coupled to one end of a tendon and a pump connected to the jack via a pressure supply conduit to supply a pressurized fluid to the jack to apply a tension force to the tendon, the system being configured to monitor the tension force of tendon disposed inside a structure in post-tensioning, the system comprising:
a displacement sensor configured to measure a real-time position of the movable piston;
a pressure sensor configured to measure a real-time pressure of the pressurized fluid in the pressure supply conduit;
a data logging memory configured to receive and store real-time data and to transmit the real-time data to a main server, the real-time data including at least one of the real-time position of the movable piston as measured by the displacement sensor and the real-time pressure of the pressurized fluid as measured by the pressure sensor; and
a control module configured to modify a flow output of the pump based on to the real-time data,
wherein the main server is configured to classify, calculate, and output the real-time data and to calculate a maximum error rate and a mean value of the real-time data.

6. A method for monitoring real-time tension force of a tendon disposed inside a structure in post-tensioning, the method comprising:
measuring real-time position data of a movable piston coupled to a jack attached to one end of the tendon;
receiving the real-time position data in a data logging memory;
storing the real-time position data in the data logging memory;
transmitting the real-time position data from the data logging memory to a main server via a wired or a wireless network;
calculating the real-time tension force of the tendon using the real-time position data; and
outputting the calculated real-time tension force to an interface, wherein calculating the real-time tension force of the tendon further includes:
obtaining a strain rate from the real-time position data; and
calculating the real-time tension force of the tendon by multiplying the strain rate by a coefficient of elasticity and an effective area of the tendon.

7. A method for monitoring real-time tension force of a tendon disposed inside a structure in post-tensioning, the method comprising:
measuring real-time position data of a movable piston coupled to a jack attached to one end of the tendon, measuring real-time pressure data of a pressure supply conduit configured to supply a pressurized fluid from a pump to the jack, and measuring a displacement of a reference point marked on an outer surface of the tendon after the pump stops supplying the pressurized fluid to the jack;
receiving the real-time position data, the real-time pressure data and the displacement of the reference point in a data logging memory;
storing the real-time position data, the real-time pressure data and the displacement of the reference point in the data logging memory;
transmitting the real-time position data, the real-time pressure data and the displacement of the reference point from the data logging memory to a main server via a wired or a wireless network;
calcul

Assignees

• Seoul Nat Univ R&Db Foundation
• Total Ps Co Ltd

Inventors

• Kang Thomas Hyun Koo
• Jeong Kee Nam

Classifications

• G01L5/06

  using mechanical means {(G01L5/042, G01L5/045 take precedence)} · CPC title

• G01L5/047

  Specific indicating or recording arrangements, e.g. for remote indication, for indicating overload or underload · CPC title

• E04G21/121 Primary

  Construction of stressing jacks · CPC title

• G01B21/02

  for measuring length, width, or thickness (G01B21/10 takes precedence) · CPC title

• G01L19/086

  for remote indication · CPC title