Evolutionary learning based sustainable strain sensing model for structural health monitoring of high-rise buildings

Structural Health Monitoring (SHM) for composite materials is becoming a primary task due to their extended use in safety critical applications. Different methods, based on the use of piezoelectric transducers as well as of fiber optics, has been successfully proposed to detect and monitor damage in composite structural components with particular attention focused on delamination cracks.In the present paper a Structural Health Monitoring model, based on the use of piezoelectric sensors, already proposed by the authors for isotropic damaged components, is extended to delaminated composite structures. The dynamic behavior of the host damaged structure and the bonded piezoelectric sensors is modeled by means of a boundary element approach based on the Dual Reciprocity BEM. The sensitivity of the piezoelectric sensors has been studied by varying the delamination length characterizing the skin/stiffener debonding phenomenon of composite structures undergoing dynamic loads.

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Self-Sensing Hybrid Composite Rod with Braided Reinforcement for Structural Health Monitoring

Materials Science Forum ◽

10.4028/www.scientific.net/msf.730-732.379 ◽

2012 ◽

Vol 730-732 ◽

pp. 379-384 ◽

Cited By ~ 1

Author(s):

Katherine P. Rosado Mérida ◽

Sohel Rana ◽

Cristiana Gonilho-Pereira ◽

Raul Fangueiro

Keyword(s):

Structural Health Monitoring ◽

Carbon Fibre ◽

Health Monitoring ◽

Glass Fibre ◽

Traffic Monitoring ◽

Strain Sensitivity ◽

Strain Sensing ◽

Braided Composites ◽

Fibre Glass ◽

Structural Health

Enhancing the performance and lightness of different structures has already been achieved by the employment of fibre reinforced composite materials. Nowadays, a new challenging perspective is being given to these materials by the inclusion of non-metallic conductive components. This emerging technology will lead to multifunctional composites with possible applications in structural health monitoring and traffic monitoring. The aim is to avoid corrosion problems from metallic components, as well as to eliminate the need of expensive equipments used for the health monitoring of large infrastructures. In the present research, the strain-sensing capability of a core-reinforced hybrid carbon fibre/glass fibre braided composite has been investigated in order to develop continuous monitoring system. The characterization of sensing behaviour was performed with the help of an instrumental set-up capable of measuring the change in electrical resistance with mechanical stresses applied to the samples. The effect of core composition (carbon fibre/glass fibre weight ratio) on the strain sensitivity of the braided composites has been studied in order to find out the optimum composition for best sensing capability. Among the three compositions studied (23/77, 47/53 and 100/0), composites with lowest amount of carbon fibre showed the best strain sensitivity with gauge factors up to 23.4 at very low flexural strain (0.55%). Attempts have also been made in this research to develop a piezoresistive matrix for the braided composites in order to further enhance their strain sensitivity. For this purpose, the strain sensing capability of an unsaturated polyester matrix dispersed with chopped carbon fibres (1mm and 3 mm lengths) at various weight % (0.5, 0.75 and 1.25%) was evaluated in order to find out their optimum length and concentration. It was observed that chopped fibres with different lengths showed similar strain sensitivity, which however, improves with the decrease in their concentrations.

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