Numerical analysis on design and application of cement-based sensor for structural health monitoring

Abstract

This article simulates the stress state and strain compatibility of the sensor embedded into concrete member to provide theoretical support for design and application of cement-based sensor. The effect of sensor dimension, voltage electrode separation, and surface roughness on strain compatibility between the embedded sensor and the concrete surrounding it is analyzed. The optimally designed sensor is embedded into concrete for health monitoring, and its stress state is investigated. A modified method for the monitoring results is proposed by studying the effect of embedded location and small deflection angle of the sensor, strength grade of concrete, amplitudes, and types of load on stress/strain compatibility. The results show that the optimum dimension and voltage electrode separation of the sensor are 20 mm × 20 mm × 40 mm and 10 mm, respectively. The sensors are nearly subjected to a uniaxial stress state when the sensor is embedded in internal strain-homogeneous area of concrete structure. The presence of the sensor will affect the stress distribution of the concrete around the sensor. The strain of the sensor is approximately coordinated with that of concrete surrounding it. The monitoring results need to be modified with the correction coefficient of corresponding effect factors to ensure monitoring accuracy.

Real-time monitoring of structures under extreme loading using smart composite-based embeddable sensors

“…Because smart cementitious composites are structural materials by nature, they can be used as a part or entire structure, providing structural properties and sensing capability. They can be utilized to develop smart/intelligent infrastructures, thereby improving the serviceability, safety, reliability and durability of infrastructures (Armoosh et al, 2022; Castañeda-Saldarriaga et al, 2021; Cui et al, 2017; Demircilioglu et al, 2020; Khushnood et al, 2019). The smart cementitious composites exhibit inherent self-sensing and damage monitoring capabilities, and are fabricated by introducing conductive functional fillers such as carbon nanofibre (CNF), carbon nanotube (CNT), steel fibre, carbon black (CB), etc.…”

“…The smart cementitious composites exhibit inherent self-sensing and damage monitoring capabilities, and are fabricated by introducing conductive functional fillers such as carbon nanofibre (CNF), carbon nanotube (CNT), steel fibre, carbon black (CB), etc. into cement matrix (Demircilioglu et al, 2020; Armoosh et al, 2022; Cassese et al, 2021; Castañeda-Saldarriaga et al, 2021; Cui et al, 2017; D’Alessandro et al, 2021; García-Macías et al, 2017; Han et al, 2015, 2017a; Khushnood et al, 2019; Majumder et al, 2008; Najafishad et al, 2020; Sanati et al, 2018; Ubertini et al, 2014a; Wen and Chung, 2001a). Their unique capability of change in electrical resistance under external disturbance or loading termed as ‘ piezoresistivity ’ offers a large scope as embeddable sensors for strain, stress, crack or damage monitoring of smart concrete structures (Cassese et al, 2021; D’Alessandro et al, 2021; García-Macías et al, 2017; Han et al, 2017a).…”

“…Their sensing efficiency was estimated by calculating a constant known as ‘gauge factor’. This gauge factor shows the linear correlation between change in electrical resistance with applied strain (Cassese et al, 2021; Castañeda-Saldarriaga et al, 2021; Cui et al, 2017; D’Alessandro et al, 2021; García-Macías et al, 2017; Han et al, 2017b). It has been found that the sensing capability of smart cementitious composite depends on several important parameters such as concentration of CNTs (Han et al, 2012; Rao et al, 2020, 2021), the surface modification of CNTs (Li et al, 2007), the process involved in the dispersion of CNTs (Azhari and Banthia, 2012; Konsta-Gdoutos et al, 2014; Tian et al, 2019), nature of applied load (Yoo et al, 2018a) and measuring techniques (Zhang et al, 2017).…”

Mechanical strength and self-sensing capacity of smart cementitious composite containing conductive rubber crumbs

“…Generally, one of the functionalities of the conductive cementitious composites is for structural health monitoring (SHM), due to their given piezoresistivity. Some investigators (Chung, 2002; Cui et al, 2017; Danoglidis et al, 2016; Ding et al, 2019; Dong et al, 2019c; Han et al, 2007, 2011, 2015b; Konsta-Gdoutos and Aza, 2014; Liu et al, 2018; Ou and Han, 2009; Wang and Chung, 1998; Xiao et al, 2010, 2011; Yoo et al, 2019) have studied the piezoresistivity of conductive cementitious composites with different conductors, such as carbon fibres, carbon nanotubes and carbon black, and concluded the improved sensing capacity for the composites reinforced by nanomaterials, especially for those possessing longer aspect ratios (Baeza et al, 2013; Chen et al, 2004; Park et al, 2010). Dong et al (2019e) and Han et al (2015a) summarized various factors, ranging from raw materials, manufacturing procedures, loading regimes, resistivity measurements to environmental factors, which influence the piezoresistivity of cementitious composites, and they compared results from different investigations with clarifications.…”

Selection and Characterization of Packaged FBG Sensors for Offshore Applications

“…Structural health monitoring (SHM) refers to detecting and analyzing the changes in structures, and indicating damage and property degradation [ 1 ]. The SHM system, which detects the changes of various parameters including strain, vibration, temperature, and so on, can help evaluate the design assumptions and parameters for existing structures, as well as provide relevant information to improve the design specifications for future similar structures [ 2 , 3 ].…”