Feasibility Study of Real-Time Monitoring of Pin Connection Wear Using Acoustic Emission

Abstract

Pin connections are one of the most important connecting forms and they have been widely used in engineering fields. In its service, pin connections are subject to wear, and it will be beneficial if the health condition of pin connections can be monitored in real time. In this paper, an acoustic emission (AE)-based method was developed to monitor wear degree of low rotational speed pin connections in real time in a nondestructive way. Most pin connections are operated at low rotational speed. To facilitate the research, an experimental apparatus to accelerate the wear test of low rotational speed pin connections was designed and fabricated. The piezoceramic AE sensor was mounted on the test apparatus in a nondestructive way, and it was capable of real-time monitoring. Accelerated wear tests of low rotational speed pin connections were conducted. To verify the results of the AE technique, a VHX-600E digital (from Keyence, Osaka, Japan) microscope was applied to observe the micrographs of the tested pins. The experimental results show that AE activity existed throughout the entire wear process, and it was the most prominent in the serious wear phase. The wear degree of the pin connections can be reflected qualitatively by the signal strength and the accumulative signal strength of the AE signals. In addition, two different wear forms can be distinguished by comparing the signal strength values of all specimens. Micrographs of all specimens confirm these results, and determine that the two wear forms include adhesive wear and abrasive wear. Furthermore, AE results demonstrated that adhesive wear is the main mode of wear for the low rotational speed pin connections, and the signal strength of the adhesive wear is around 190 times larger than that of abrasive wear. This feasibility study demonstrated that the developed acoustic emission technique can be utilized in the wear monitoring of pin connections in real time in a nondestructive way.

Piezoceramic-Based Damage Monitoring of Concrete Structure for Underwater Blasting

“…Lile any other piezoelectric material, PZT has a direct piezoelectric effect and an inverse piezoelectric effect. PZT transducers can be embedded in or bonded on a concrete structure for health monitoring [62][63][64]. In this research, a PZT-based active-sensing method is proposed to monitor blast-induced damage in a concrete structure; Figure 3 illustrates this principle.…”

Detecting of the Longitudinal Grouting Quality in Prestressed Curved Tendon Duct Using Piezoceramic Transducers

“…Among various piezoceramic materials, lead zirconate titanate (PZT) has the strongest piezoelectric effect and can be fabricated in different shapes [39,40]. With proper protection, various PZT based transducers that are suitable for deployment in civil structures, including the concrete structures, have been developed [41][42][43][44], and have found application in bridge structural health monitoring [45][46][47]. The active sensing method based on piezoceramic transducers is to bond PZT transducers on the surface of structure [48] or embed piezoelectric transducers in the structure [49], and then the actuator generates the signals, which is detected by the sensors.…”

Structural Damage Detection and Health Monitoring

“…PZT has high bandwidth [58,59] and is often used to fabricate acoustic emission sensors/probes [27,49]. As reported in this special issue, PZT transducers have demonstrated the potential for a staggering range of applications [25][26][27]35,42,49], including the development of smart transducers that have recently shown to be able to monitor the health of structural components and interfaces and detect debonding and delamination damages. A recent development has even demonstrated the ability to use piezoelectric transducers to communicate information across a structure [60], potentially also picking up on damage as the stress waves propagate across the structure.…”

“…damage at a shorter time frame than typical monitoring techniques. Examples include the use of vibration and acoustic signals to detect water leaks [47], the use of infrared to detect damage in beams [48], utilizing acoustic emission to detect wearing in pin connections [49], and the training of deep learning neural networks to identify damage in composite pipelines [50], and much more [51].…”

“…An interesting subset of the research on SHM and damage detection is driven by the multi-functionalities of piezoelectric materials [52][53][54], such as PZT (Lead Zirconate Titanate), which has a strong piezoelectric effect and is often used to generate and detect stress waves for SHM [55][56][57]. PZT has high bandwidth [58,59] and is often used to fabricate acoustic emission sensors/probes [27,49]. As reported in this special issue, PZT transducers have demonstrated the potential for a staggering range of applications [25][26][27]35,42,49], including the development of smart transducers that have recently shown to be able to monitor the health of structural components and interfaces and detect debonding and delamination damages.…”