Influence of Cracks on Frequency of the Self-Vibration of Reinforced Concrete T Beam of Road Bridges

2019 ◽  
Vol 828 ◽  
pp. 9-13 ◽  
Author(s):  
Artashes Sargsyan ◽  
Grigor Sargsyan ◽  
Boris Resnik
Keyword(s):  
Reinforced Concrete ◽  
Health Monitoring ◽  
Theoretical Calculations ◽  
Health Condition ◽  
The Self ◽  
Correct Evaluation ◽  
Bridge Health Monitoring ◽  
Structure Vibration ◽  
Different Characteristics ◽  
T Beam

The main goal of bridge health monitoring is to show the condition of structure in real time mode with using special sensors, which can measure different characteristics, which can indicate about the changes in structure. One of the easier measured indicators what can be used is frequency of structure vibration. The diagnostic of the health condition of structure is dependent of correct evaluation of changes range of measured indicators. This paper presents the theoretical calculations to study the effect of cracking on the frequency response of typical reinforced concrete T type beams which has widespread in road bridges construction.

Damage Identification of T-Beam Bridge Based on Distributed Long-Gauge Strain Mode Theory

2014 ◽  
Vol 501-504 ◽  
pp. 1352-1358
Author(s):  
Bi Tao Wu ◽  
Gang Wu ◽  
Cai Qian Yang
Keyword(s):  
Reinforced Concrete ◽  
Strain Amplitude ◽  
Health Monitoring ◽  
Damage Identification ◽  
Amplitude Variation ◽  
Strain Mode ◽  
Mode Theory ◽  
Sensor Arrangement ◽  
Beam Bridge ◽  
T Beam

Damage identification of a T-beam bridge which contains five T-beams is conducted based on distributed long - gauge strain mode theory, considering the damage and aging problems of widely used simple-supported reinforced concrete T-beam bridges. Assuming that the damage occurs in the different T-beams, the normalized strain mode is used to identify the damage. The sensitivity of the normalized strain mode of each T-beam and change rule of strain mode curve is studied at the same time. It is effective to apply modal strain amplitude variation degree to detect damages. If sensors are arranged reasonablely, a good damage identification can be obtained by utilizing distributed long-gauge strain mode theory even if the damage is slight.Some suggestions are given for the sensor arrangement and health monitoring of this kind of bridge when using the distributed long-gauge strain mode theory at last.

The Bridge Health Monitoring System Based on SCM

2012 ◽  
Vol 226-228 ◽  
pp. 1661-1664
Author(s):  
Xiao Ling Zhu ◽  
Xue Li Chen ◽  
Ying Yao
Keyword(s):  
Monitoring System ◽  
Health Monitoring ◽  
Health Condition ◽  
Sensor Nodes ◽  
Structure Characteristic ◽  
Control Center ◽  
Health Monitoring System ◽  
Bridge Health Monitoring ◽  
Characteristic Signal ◽  
Measurement And Control

It plays a very important role for the national economy and social security to gain bridge structure characteristic signal scientifically, to evaluate the bridge health condition and to guarantee long-term safe operation. The bridge health monitoring system is a major technique to settle those problems, which is in charge of working status inspection, health detection and alarm via field data, providing a solid safeguard for well-balanced operation of the bridge as well as the security of people’s life and property. This paper proposes a bridge health monitoring system based on wireless sensor network, which collects information of each mechanical part of the bridge. Sensor nodes form a smart measurement, and control network through self-organization, then transmit to the control center through network, by this way we can achieve real-time automatic remote monitoring on the bridge health.

Temperature Compensation in Deformation Testing for Smart Concrete Structures

2006 ◽  
Vol 326-328 ◽  
pp. 1503-1506 ◽  
Author(s):  
Xian Hui Song ◽  
Li Xia Zheng ◽  
Zhuo Qiu Li
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Health Monitoring ◽  
Difference Method ◽  
Temperature Compensation ◽  
Concrete Structures ◽  
Fiber Reinforced Concrete ◽  
Experimental Results ◽  
Measured Deformation ◽  
Different Characteristics

Carbon fiber reinforced concrete (CFRC) structures exhibit both strain sensibility and temperature sensibility, which are coupled with each other when used in traffic or health monitoring for concrete structures. This coupling property results in inaccurateness of measured deformation. In this paper Four-probe Difference Method is used to detach the above two effects according to loaded conditions of structures and different characteristics of the two effects. The theoretical and experimental results indicate that the method is feasible and effective.

scholarly journals Numerical Parametric Study on the Effectiveness of the Contact-Point Response of a Stationary Vehicle for Bridge Health Monitoring

2021 ◽  
Vol 11 (15) ◽  
pp. 7028
Author(s):  
Ibrahim Hashlamon ◽  
Ehsan Nikbakht ◽  
Ameen Topa ◽  
Ahmed Elhattab
Keyword(s):  
Numerical Model ◽  
Health Monitoring ◽  
Contact Point ◽  
Response Spectra ◽  
Roughness Effects ◽  
Moving Vehicle ◽  
Bridge Health Monitoring ◽  
Vehicle Response ◽  
Instrumented Vehicle ◽  
The Time Domain

Indirect bridge health monitoring is conducted by running an instrumented vehicle over a bridge, where the vehicle serves as a source of excitation and as a signal receiver; however, it is also important to investigate the response of the instrumented vehicle while it is in a stationary position while the bridge is excited by other source of excitation. In this paper, a numerical model of a stationary vehicle parked on a bridge excited by another moving vehicle is developed. Both stationary and moving vehicles are modeled as spring–mass single-degree-of-freedom systems. The bridges are simply supported and are modeled as 1D beam elements. It is known that the stationary vehicle response is different from the true bridge response at the same location. This paper investigates the effectiveness of contact-point response in reflecting the true response of the bridge. The stationary vehicle response is obtained from the numerical model, and its contact-point response is calculated by MATLAB. The contact-point response of the stationary vehicle is investigated under various conditions. These conditions include different vehicle frequencies, damped and undamped conditions, different locations of the stationary vehicle, road roughness effects, different moving vehicle speeds and masses, and a longer span for the bridge. In the time domain, the discrepancy of the stationary vehicle response with the true bridge response is clear, while the contact-point response agrees well with the true bridge response. The contact-point response could detect the first, second, and third modes of frequency clearly, unlike the stationary vehicle response spectra.

scholarly journals Challenges in Bridge Health Monitoring: A Review

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4336
Author(s):  
Piervincenzo Rizzo ◽  
Alireza Enshaeian
Keyword(s):  
United States ◽  
Health Monitoring ◽  
Highway Bridges ◽  
The United States ◽  
Anomalous Behavior ◽  
Existing Structures ◽  
Bridge Health Monitoring ◽  
Using Data ◽  
The Many ◽  
Major Factors

Bridge health monitoring is increasingly relevant for the maintenance of existing structures or new structures with innovative concepts that require validation of design predictions. In the United States there are more than 600,000 highway bridges. Nearly half of them (46.4%) are rated as fair while about 1 out of 13 (7.6%) is rated in poor condition. As such, the United States is one of those countries in which bridge health monitoring systems are installed in order to complement conventional periodic nondestructive inspections. This paper reviews the challenges associated with bridge health monitoring related to the detection of specific bridge characteristics that may be indicators of anomalous behavior. The methods used to detect loss of stiffness, time-dependent and temperature-dependent deformations, fatigue, corrosion, and scour are discussed. Owing to the extent of the existing scientific literature, this review focuses on systems installed in U.S. bridges over the last 20 years. These are all major factors that contribute to long-term degradation of bridges. Issues related to wireless sensor drifts are discussed as well. The scope of the paper is to help newcomers, practitioners, and researchers at navigating the many methodologies that have been proposed and developed in order to identify damage using data collected from sensors installed in real structures.

Internet of things-based cloud computing platform for analyzing the physical health condition

2021 ◽  
pp. 1-15
Author(s):  
Mengyao Cui ◽  
Seung-Soo Baek ◽  
Rubén González Crespo ◽  
R. Premalatha
Keyword(s):  
Cloud Computing ◽  
Internet Of Things ◽  
Health Monitoring ◽  
Tracking System ◽  
Disease Diagnosis ◽  
Health Condition ◽  
Computing Platform ◽  
Concept Model ◽  
Patient Health ◽  
Cloud Servers

BACKGROUND: Health monitoring is important for early disease diagnosis and will reduce the discomfort and treatment expenses, which is very relevant in terms of prevention. The early diagnosis and treatment of multiple conditions will improve solutions to the patient’s healthcare radically. A concept model for the real-time patient tracking system is the primary goal of the method. The Internet of things (IoT) has made health systems accessible for programs based on the value of patient health. OBJECTIVE: In this paper, the IoT-based cloud computing for patient health monitoring framework (IoT-CCPHM), has been proposed for effective monitoring of the patients. METHOD: The emerging connected sensors and IoT devices monitor and test the cardiac speed, oxygen saturation percentage, body temperature, and patient’s eye movement. The collected data are used in the cloud database to evaluate the patient’s health, and the effects of all measures are stored. The IoT-CCPHM maintains that the medical record is processed in the cloud servers. RESULTS: The experimental results show that patient health monitoring is a reliable way to improve health effectively.

scholarly journals Toward Structural Health Monitoring of Civil Structures Based on Self-Sensing Concrete Nanocomposites: A Validation in a Reinforced-Concrete Beam

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Diego L. Castañeda-Saldarriaga ◽  
Joham Alvarez-Montoya ◽  
Vladimir Martínez-Tejada ◽  
Julián Sierra-Pérez
Keyword(s):  
Reinforced Concrete ◽  
Damage Detection ◽  
Direct Current ◽  
Health Monitoring ◽  
Electrical Resistance ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Structural Member ◽  
Rc Beam ◽  
Electric Resistance

AbstractSelf-sensing concrete materials, also known as smart concretes, are emerging as a promising technological development for the construction industry, where novel materials with the capability of providing information about the structural integrity while operating as a structural material are required. Despite progress in the field, there are issues related to the integration of these composites in full-scale structural members that need to be addressed before broad practical implementations. This article reports the manufacturing and multipurpose experimental characterization of a cement-based matrix (CBM) composite with carbon nanotube (CNT) inclusions and its integration inside a representative structural member. Methodologies based on current–voltage (I–V) curves, direct current (DC), and biphasic direct current (BDC) were used to study and characterize the electric resistance of the CNT/CBM composite. Their self-sensing behavior was studied using a compression test, while electric resistance measures were taken. To evaluate the damage detection capability, a CNT/CBM parallelepiped was embedded into a reinforced-concrete beam (RC beam) and tested under three-point bending. Principal finding includes the validation of the material’s piezoresistivity behavior and its suitability to be used as strain sensor. Also, test results showed that manufactured composites exhibit an Ohmic response. The embedded CNT/CBM material exhibited a dominant linear proportionality between electrical resistance values, load magnitude, and strain changes into the RC beam. Finally, a change in the global stiffness (associated with a damage occurrence on the beam) was successfully self-sensed using the manufactured sensor by means of the variation in the electrical resistance. These results demonstrate the potential of CNT/CBM composites to be used in real-world structural health monitoring (SHM) applications for damage detection by identifying changes in stiffness of the monitored structural member.

Sign in / Sign up

Export Citation Format

Share Document