Composite materials are widely used. These materials are used in various sectors such as aviation, rockets, space industry, modern transport, including buses, trams and recreational boats, personal protective equipment such as helmets, bulletproof vests, bulletproof coatings, compasses, gas pipelines. Usually, due to the required high strength and low weight, composites are used, which are of various thicknesses and layers, reinforced with carbon fiber (CFRP), glass fiber (GFRP). Considering that in many cases the structure made of such composites must be very strong even in extreme conditions, the quality requirements for such materials are also very high. The operation of products and structures with defects can cause injuries/deaths to people and losses to production or the ecosystem.
One of the main quality assurance procedures is the non-destructive assessment of composite materials and products made from them. This means that in a number of cases, production technologies face a problem and do not allow the use of contact measurement methods for measuring and controlling the properties of products. Ultrasonic methods enable the study of important properties of materials that cannot be assessed by traditional methods. Guided waves inside the test object are suitable for this purpose. Guided waves are widely used in non-destructive testing and inspection of sheet structures. In order to expand the possibilities of non-destructive testing, it becomes relevant to excite waves inside composite materials and use them for research. Most often, they are excited by transmitting the vibrations of an acoustic transducer to the product under study by contact through a thin liquid gap. However, in many cases, liquids cannot be used, because the test object itself will be contaminated, damaged or otherwise negatively affected. This is relevant when studying paper, cardboard, films, composite structures, which are used in many areas, including the aerospace industry.
The aim is to detect defects using non-contact ultrasonic measurement methods intended for research of the properties of sheet composite structures.
Tasks:
1. To study/get acquainted with the methods of non-contact excitation and reception of ultrasonic waves in sheet composite structures, their application, including airborne transducers and arrays;
2. To evaluate the advantages and disadvantages of ultrasonic measurement methods, to select the optimal ultrasonic method(s) and ultrasonic transducers/arrays for measurements of sheet composite structures;
3. To conduct experimental studies of sheet composite structures using non-contact measurement method(s) and to identify defect(s) of sheet composite structures;
4. To prepare a report (oral) at a conference organized by LMT;
5. Preparation of a project report.
Period of project implementation: 2026-07-01 - 2026-08-31
Project coordinator: Kaunas University of Technology
