In recent decades, novel composite materials based on lightweight honeycombs have been used in a wide range of industries. The object of the investigation is a honeycomb-based engineering structure of a multi-layered composite made of fibre glass-epoxy laminating layers and a core of the epoxy impregnated paper. Different types of constructions (storage tanks, pipelines, etc.) possess cylindrical shapes and are produced using the winding process. Therefore, the final products may have a variation of thickness and unevenly impregnated honeycomb core layer. To meet quality and structural integrity requirements, such structures are necessary to be tested against delaminations inside the covering panels and disbonds between the covering panels and the core.This research aimed to develop ultrasonic measurement and structure health monitoring (SHM) technique for testing honeycomb-based storage vessels.Development of simple in operation and durable SHM technique is essential in order to ensure the safety of liquid storage tanks against overpressure etc., and detection of various types of defects that may appear during transportation, installation and exploitation of those structures. Typical defects aimed at being detected are relatively large delaminations or disbonds (lateral dimensions more than 100&nbsp;mm) caused by low energy impacts that cannot be detected by visual observation and possess a severe influence on the structural strength.In this work, the results of numerical modelling and experimental investigations illustrated propagation of low frequency ultrasonic guided waves (UGW) in a sample of honeycomb composite. Finite element simulation has been performed to investigate propagation effects of UGW and select the necessary quantity and placement of ultrasonic transducers. The possibilities to place ultrasonic transmitter and receivers on both sides of the composite construction and use the proposed technique for detecting disbond areas caused by low energy impacts or semi-static loads (e.g. filling and draining of liquid from a storage tank) were proved by experimental testing.&nbsp;The SHM experiments during the compressive tests in a lab have demonstrated that due to deformation of the composite structure, the amplitudes of the received UGW drop down, and the residual effects can be noticed after the relaxation of the structure. It was demonstrated that the proposed SHM system is suitable to be used for the detection of significant mechanical loads and the appearance of disbond type defects.Keywords: structure health monitoring; ultrasonic guided waves; composite materials; honeycomb; embedded transducers; disbond; defect

Application of Ultrasonic Guided Waves for Shm of Composite Honeycomb Constructions

Paper Proceedings: https://asmedigitalcollection.asme.org/qnde/QNDE2021/volume/85529

ASME 2021 48th Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.