Research on weld surface notch monitoring based on microstrip antenna sensor array

Abstract

In engineering welding structures, crack defects easily occur due to various materials and joint forms. In this paper, to ensure structural safety, a microstrip antenna sensor line array was designed and analyzed for monitoring weld cracks. The crack monitoring sensitivity of the antenna sensor is defined as the amount of antenna frequency shift for 1 mm of crack length growth. The patch size was determined to be 100 × 60 mm, which was based on the influence of patch size on sensor monitoring sensitivity. The distance of array elements was determined by the experiments of array element distance and crack propagation. The line array of microstrip antenna sensor was fabricated, and the experiment of weld crack identification was performed. The signals of each array element were distinguished according to the principle of delay line. The experimental results show that the sensor array can accurately identify the weld crack location according to the shift of resonant frequency, and the crack monitoring sensitivity of the sensor array reaches about 5 MHz mm−1.

A Review of Radio Frequency Identification Sensing Systems for Structural Health Monitoring

“…The surface of the metallic structure under test can be regarded as the specific ground plane of the antenna and thus can be effectively used for a metal environment. For example, rectangular [ 23 , 68 , 69 , 104 , 105 , 106 ] and circular patch [ 13 , 25 , 107 , 108 ] antennas with different structures are being developed for strain [ 23 , 25 , 104 , 105 , 107 ], crack [ 68 , 69 , 106 , 108 , 109 ], and corrosion [ 13 ] sensing of metal structures. In addition, developing an absorbing material [ 110 ] and utilizing specific electromagnetic band gap structures [ 111 ] are effective methods to solve the anti-metal problem.…”

Decoupled Monitoring Method for Strain and Cracks Based on Multilayer Patch Antenna Sensor

“…In this section, crack growth on the structural surface under a stress field is simulated in the HFSS software and the effects of crack growth and strain on the resonant frequencies of the patches in each layer are analyzed [ 26 , 27 ]. The simulation model diagram is shown in Figure 10 .…”

Metamaterial surface and modified Vivaldi antenna to tune gain of microwave imaging instrument

“…The simulated CAD file of the proposed Vivaldi antenna named 'Ant3' is used to generate the masks for both sides of the antenna. These masks are used to etch the structure on the FR-4 substrate using a chemical etching process [35]. The masks were superimposed onto the FR-4 substrate by applying pressure at high temperature and then the outcome was dipped in the ferric chloride solution until the excessive copper was etched from the substrate.…”