We report remote strain and displacement measurement during elastic and plastic deformation using a metamaterial-based wireless and passive sensor. The sensor is made of a comb-like nested split ring resonator (NSRR) probe operating in the near-field of an antenna, which functions as both the transmitter and the receiver. The NSRR probe is fixed on a standard steel reinforcing bar (rebar), and ...

the use of unbounded tendons is common in prestressed concrete structures and evaluation of the stress increase in unbonded tendons at ultimate flexural strength of such structure has posed a great challenge over the years. based on the bending experiment for two-span continuous post-tension beams with unbounded tendons and externally applied cfrp sheets, the monitoring of the stress increment ...

In this initial study it is investigated the possibility of using simple artificial neural network for classification of kick techniques based on their specific force course profile. The aim is to investigate whether the neural networks could be a suitable tool for such task and can be possibly used in following research that will deal with classification of punch techniques and also the strike...

Abstract The extension of 2D ferromagnetic structures into 3D curved geometry enables to tune its magnetic properties such as uniaxial anisotropy. Tuning the anisotropy with strain and curvature has become a promising ingredient in modern electronics, flexible stretchable magnetoelectronic devices, impedance-based field sensors, gauges, however, been limited extended thin films only moderate be...

Pencil traces drawn on print papers are shown to function as strain gauges and chemiresistors. Regular graphite/clay pencils can leave traces composed of percolated networks of fine graphite powders, which exhibit reversible resistance changes upon compressive or tensile deflections. Flexible toy pencils can leave traces that are essentially thin films of graphite/polymer composites, which show...

The standard methodology for measuring loads in long bones is the in situ load cell, which enables direct measurements, but alters the stiffness and mass of the subject bone. Bone loading can also be calculated by applying linear beam theory to measurements from strain gauges affixed to the bone surface. The efficacy of the strain gauge method was assessed in this study by mounting three strain...

A miniaturized strain gauge with a thickness of 5 µm is molded into a silicone O-ring. This is a first step toward embedding sensors in gaskets for structural health monitoring. The signal of the integrated sensor exhibits a linear correlation with the contact pressure of the O-ring. This affords the opportunity to monitor the gasket condition during installation. Thus, damages caused by faulty...

The structural health of airframes is often monitored by analysis of the frequency of occurrence matrix (FOOM) produced after each flight. Each cell in the matrix records a stress event of a particular severity. These matrices are used to determine how much of the aircraft’s life has been used up in each flight. Unfortunately, the sensors that produce this data are subject to degradation themse...