Study of thermophysics during diamond drilling of fibreglass and carbon fibre-reinforced polymer composites

This paper examines thermophysics of the drilling process of polymeric composite materials, such as carbon-fibre-reinforced plastics (CFRP) and fibreglass by tubular diamond drill bits. Features of the COMSOL Multiphysics engineering software package were used. We employed Fourier heat equations, which express the intensity of heat gain by a mobile source in a moving coordinate system. The research was performed using the proprietary method of modelling spatial thermal action upon drilling polymer composite materials (fibreglass and carbon-fibre-reinforced plastics) in the COMSOL Multiphysics software environment. A tubular diamond drill bit with a diameter of 10 mm with two slots was chosen as a model cutting tool. Solid plates with a thickness of 5.5 mm made of layered fibrous polymer composite materials (fibreglass, carbon-fibre-reinforced plastic) were used as a preform. As a result of computer calculations, we obtained temperature fields of fibreglass and carbon-fibre-reinforced plastic during diamond drilling with a tubular tool. When studying the thermal behaviour of fibreglass and carbon-fibre-reinforced plastics, maximum temperature fields were located. The study revealed that the temperature reaches 413.6 and 448.7 K during CFRP and fibreglass drilling, respectively. It was shown that the distance of heat transfer from the edge of the hole into the preform was 6.42 and 6.40 mm for CFRP and fibreglass, respectively. A method of modelling the thermal effects when cutting polymer composite materials developed in the COMSOL Multiphysics environment allows complex analytical calculations of temperatures induced by drilling to be simplified. In addition, its use prevents overheating of a preform during drilling, allows assessing the depth of heat distribution inside the preform from the edge of the formed hole in different polymer composite materials. These measures increase the machining quality of polymer composite materials.

Studying a grinding method of sapphire pipes using two grinders

This paper examines the thermophysics of a drilling process of polymeric composite materials such as carbonfibre-reinforced plastics (CFRP) and fibreglass by tubular diamond drill bits. Features of the COMSOL Multiphysics engineering software package were used. We employed Fourier heat equations, which express the intensity of heat gain by a mobile source in a moving coordinate system. The research was performed using the proprietary method of modelling spatial thermal action upon drilling polymer composite materials (fibreglass and carbon-fibre-reinforced plastics) in the COMSOL Multiphysics software environment. A tubular diamond drill bit with a diameter of 10 mm with two slots was chosen as a model cutting tool. Solid plates with a thickness of 5.5 mm made of layered fibrous polymer composite materials (fibreglass, carbon-fibre-reinforced plastic) were used as a preform. As a result of computer calculations, we obtained temperature fields of fibreglass and carbon-fibre-reinforced plastic during diamond drilling with the tubular tool. When studying the thermal behaviour of fibreglass and carbon-fibre-reinforced plastics, maximum temperature fields were located. The study revealed that the temperature reaches 413.6 K and 448.7 K during CFRP and fibreglass drilling, respectively. It was shown that the distance of heat transfer from the edge of the hole into the preform was 6.42 and 6.40 mm for CFRP and fibreglass, respectively. A method of modelling the thermal effects when cutting polymer composite materials developed in the COMSOL Multiphysics environment allows complex analytical calculations of temperatures induced by drilling to be simplified. In addition, it helps avoid overheating of a preform during drilling, allows the depth of heat distribution inside the preform from the edge of the formed hole in different polymer composite materials to be assessed. These measures lead to increasing the machining quality of polymer composite materials.

Research underway in the Minakuchi Lab – new fiber features to control crack propagation in composite materials

Composite materials are materials that are made by combining one or two materials. Composite materials have been used by humans for thousands of years but as technological developments increase, more and more examples of composite materials have been created which has led to a staggering number of innovations in a wide range of different fields. One major example of this is the aerospace industry which relies on materials that are strong but light. It is essential that an aircraft is strong enough to resist the enormous stresses that are placed on it by its mechanisms and the environment in which it operates, but light enough to be propelled thousands of miles into the sky. Some of the most abundant composite materials used in the aerospace industry are carbon fibre reinforced plastics (CFRP) which are the focus of Dr Shu Minakuchi's research team at the Minakuchi Laboratory within the Department of Aeronautics and Astronautics, The University of Tokyo. Minakuchi's team is working on advanced composite materials represented by CFRPs, with a view to overcoming some of the problems associated with cracks from stresses and their propagation.