Power-efficient piezoelectric fatigue measurement using long-range wireless sensor networks

Abstract

In this paper we describe the design of a proof-of-concept wireless embedded sensor system for continuous strain cycle monitoring as a method for fatigue life assessment on civil structures. Monitoring of strain cycles is energy demanding, and therefore not suited to energy-constrained devices, as it requires continuous acquisition of strain data with a high sampling rate, followed by data processing using algorithms for peak-trough detection and cycle counting. To overcome this drawback, at the core of our proposed design is a piezoelectricbased analogue sensor system that can achieve as much as a factor of 9 increase in energy efficiency compared with the conventional approach. The key component is an analogue peak-trough detector that offloads the computation in peak-trough detection from the microcontroller, thus eliminating the need for continuous sampling. The function of the detector is coupled with an energy-efficient interrupt-driven software design for acquisition and strain cycles calculation, which is carried out by using a standard form of the rainflow cycle counting algorithm. For wireless communication and networking, LoRa and LoRaWAN are adopted as core modules. We illustrate the performance of our proposed solution by way of simulation and laboratory experiments. Results show a good agreement in measurement of strain cycles between our proposed system and the conventional approach. Thus, our solution proves to be promising for real fatigue measurement applications.

High‐Performance Piezoelectric Nanogenerator of BTO‐PVDF Nanofibers for Wearable Sensing

“…Among these crystalline phases, 𝛽-phase crystals exhibit the highest piezoelectric response due to their high dipole moment and spontaneous polarization. [10,11] PVDF with higher 𝛽-phase crystallization usually exhibits better piezoelectric properties and thus plays a more significant role in practical applications.…”

Fluorinated Barium Titanate Nanoparticles for Wearable Piezoelectric Power Generation

“…The β-phase is one of the highest piezoelectric responses among the five crystalline phases, due to its high dipole moment and spontaneous polarization. 13,14 To enhance the β-phase content of PVDF, a number of methods including electrospinning, mechanical stretching, electrical poling, and so on are used. Among these methods used to enhance the β-phase content of PVDF, electrospinning is one of the most facile and effective methods, and the applied voltage is beneficial to obtaining PVDF nanofibers with high β-phase content during the spinning process.…”

“…There are five crystalline phases of PVDF: α-phase, β-phase, γ-phase, δ-phase, and ε-phase. The β-phase is one of the highest piezoelectric responses among the five crystalline phases, due to its high dipole moment and spontaneous polarization. , To enhance the β-phase content of PVDF, a number of methods including electrospinning, mechanical stretching, electrical poling, and so on are used. Among these methods used to enhance the β-phase content of PVDF, electrospinning is one of the most facile and effective methods, and the applied voltage is beneficial to obtaining PVDF nanofibers with high β-phase content during the spinning process. , In addition to these methods, the method of filler addition provides a simple and effective approach to improve the β-phase content of PVDF nanofibers for the piezoelectric property .…”

Failure criteria for real-time assessment of ductile cast irons subjected to various loading conditions

“…Structural health monitoring (SHM) of critical structures, such as bridges, pipelines, and power industry facilities, represents an issue of great interest [1,2]. The deterioration of the structural integrity of such systems affects both public safety and the international economy.…”