Damage assessment of carbon fibre reinforced plastic using acoustic emission technique: experimental and numerical approach

2020 ◽  
pp. 147592172094643
Author(s):  
Claudia Barile ◽  
Caterina Casavola ◽  
Giovanni Pappalettera ◽  
Vimalathithan Paramsamy Kannan
Keyword(s):  
Finite Element ◽  
Acoustic Emission ◽  
Carbon Fibre ◽  
Crack Length ◽  
Research Work ◽  
Numerical Approach ◽  
Acoustic Energy ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
Carbon Fibre Reinforced Plastic

In this research work, the acoustic emission results obtained from testing double cantilever beam specimens with carbon fibre reinforced plastic laminates are analysed. The acoustic emission descriptors such as amplitude, frequency centroid, counts, duration and risetime are clustered using k-means++ algorithm. An unconventional and innovative way of using the acoustic emission descriptors, after the clustering, is introduced. This method can favourably be used for relating the different damage progression modes in fibre reinforced plastics. Apart from this, the cumulative acoustic energy is used for predicting the crack length of the specimens. The predicted crack length is almost identical to the actual crack length opening recorded in each specimen. Finally, analytical and finite element models are used for validating the experimental results under the mode I delamination. The finite element studies are carried out using cohesive zone modelling in Comsol Multiphysics® platform.

scholarly journals Engineering of three-dimensional near-net-shape weave structures for high technical performance in carbon fibre–reinforced plastics

2019 ◽  
Vol 14 ◽  
pp. 155892501986123
Author(s):  
Stefan Schindler ◽  
Hans-Jürgen Bauder ◽  
Jürgen Wolfrum ◽  
Jürgen Seibold ◽  
Nemanja Stipic ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Material Flow ◽  
Three Dimensional ◽  
Cost Accounting ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
Weaving Technology ◽  
Near Net Shape ◽  
Carbon Fibre Reinforced Plastic ◽  
Carbon Fibre Reinforced Plastics

To tap the full potential of reinforcing fibres for lightweight construction of sustainable carbon fibre–reinforced plastic components, woven three-dimensional reinforcement structures open up innovative approaches by integrating functional features. In this work, a novel three-dimensional shuttle weaving technology was taken advantage of to study carbon reinforcement structures with uninterrupted load trajectories from three points of view. Mechanical principals, economic and environmental issues were focused to provide an overall picture. Near-net-shape reinforcement fabrics with load trajectory–compliant yarn paths and interconnected layers that are interwoven in thickness direction were objects of investigation. The effects of a closed fabric selvedge, only producible by shuttle weaving, were investigated too. The here presented novel technology enables complex woven reinforcement structures that otherwise would demand several fabric layers leading to limited properties and lower performance of the carbon fibre–reinforced plastics due to missing interconnections between the layers. The studies on exemplary rods revealed a close relationship between different three-dimensional weave structures and the carbon fibre–reinforced plastic’s mechanical properties. The three-dimensional structures were woven in a single-step process and subsequently infiltrated with epoxy resin in the Vacuum Assisted Process (VAP®) and mechanically tested. Rounding off, universal guidelines for the layout of three-dimensional fabrics for rods were derived therefrom. The economic and environmental aspects of the complete process line were compared to the conventional manufacturing procedures for carbon fibre–reinforced plastic by material flow cost accounting. Looking at sustainability, material flow cost accounting showed that lightweight three-dimensional components with integrated features can be produced cost-effectively with less environmental impact by the novel weaving technology. Its capability for high-quality serial production of three-dimensional reinforcement structures is evident, which was one major result of the work.

scholarly journals Validation of Microscopy Measured Porosity in Carbon Fibbers Composites

2019 ◽  
Vol 26 (4) ◽  
pp. 83-90
Author(s):  
Arnold Jędral ◽  
Anna Bona
Keyword(s):  
Carbon Fibre ◽  
Standard Test ◽  
Test Method ◽  
Testing Methods ◽  
Destructive Testing ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
Carbon Fibre Reinforced Plastic ◽  
Observation Method ◽  
Quality Instrument

AbstractOne of the most common defects in carbon fibre reinforced plastics (CFRP) is porosity. Too much of those defects could be serious problems to mechanical properties, which directly take effect on elements safety, like aircrafts. Therefore, the evaluation of porosity is very important test. Microscopic observations are widely used as a quality instrument in materials and constructions inspections. Cross section image of a material is easy to prepare and analyse. Porosity of a carbon fibre reinforced plastic can be clearly spot in such kind of images. Study shows that in the most cases porosity appear between layers of fibres, rather between fibres. Unfortunately, image from microscope is only 2D picture from a small representative region. Because of that, comparison of 2D image to a real porosity distribution in all volume of a material is very difficult. To verify 2D microscopic observation method is necessary to perform another kind of tests. In this article, authors focused on non-destructive (NDT) and destructive testing methods. 2D porosity images from light microscope were compared with three different testing methods: ultrasonic test (UT), computed tomography (CT) test and constituent content of composite materials standard test method according to ASTM D3171 – 15, procedure B. Porosity results obtained from dissolution of resin from the carbon-epoxy resin sample.

Finite element modelling of cutting force in shearing of multidirectional carbon fibre reinforced plastic laminates

2018 ◽  
Vol 52 (28) ◽  
pp. 3865-3874
Author(s):  
Anton Shirobokov ◽  
Fritz Klocke ◽  
Oksana Baer ◽  
Andreas Feuerhack ◽  
Daniel Trauth ◽  
...  
Keyword(s):  
Finite Element ◽  
Carbon Fibre ◽  
Cutting Force ◽  
Cutting Forces ◽  
Process Model ◽  
Kinematic Model ◽  
Functional Requirements ◽  
Reinforced Plastic ◽  
Carbon Fibre Reinforced Plastic ◽  
Plastic Components

Lightweight structural components made of carbon fibre reinforced plastics are manufactured near-net-shape. However, in order to fulfil geometrical or functional requirements, carbon fibre reinforced plastic components have to be trimmed and pierced in a finish processing step. Shearing is a highly productive technology that is potentially suitable for cost-effective finishing of carbon fibre reinforced plastic components in high-volume series production. Shearing of carbon fibre reinforced plastic has not yet been sufficiently researched. Cutting force is an important characteristic of the shearing process. Up to now, there exists limited knowledge on numerical modelling of the cutting forces in carbon fibre reinforced plastic shearing. In order to address this, a finite element process model of carbon fibre reinforced plastic trimming was developed in this work. The process modelling included a formulation of continuum mechanical material model for a unidirectional ply as well as a development of a kinematic model of the trimming process. The developed finite element process model was validated by means of experimental data. The simulated and experimentally determined maximum specific cutting forces demonstrated a very good qualitative and quantitative agreement.

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

2021 ◽  
Vol 25 (3) ◽  
pp. 290-299
Author(s):  
A. S. Dudarev ◽  
E. Kh. Gumarov
Keyword(s):  
Composite Materials ◽  
Carbon Fibre ◽  
Polymer Composite ◽  
Polymer Composite Materials ◽  
Temperature Fields ◽  
Comsol Multiphysics ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
Carbon Fibre Reinforced Plastic ◽  
Carbon Fibre Reinforced Plastics

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.

Adhesive behaviour of carbon fibre reinforced plastic panels manufactured using woven and unidirectional tape after ultraviolet laser surface treatment

2017 ◽  
Vol 52 (7) ◽  
pp. 853-865 ◽  
Author(s):  
Marta Botana-Galvín ◽  
Ginesa Blanco ◽  
Leandro González-Rovira ◽  
Miguel A Rodríguez ◽  
Francisco J Botana
Keyword(s):  
Carbon Fibre ◽  
Surface Treatment ◽  
Laser Treatment ◽  
Photoelectron Spectroscopy ◽  
Adhesive Bonding ◽  
Processing Parameters ◽  
Ultraviolet Laser ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
Carbon Fibre Reinforced Plastic

This paper describes the results obtained when ultraviolet laser treatment was performed as a surface treatment prior to adhesive bonding for two aeronautical carbon fibre-reinforced plastics based on an epoxy resin prepreg. Different laser-processing parameters were employed, and their effect on the surfaces was analysed through morphological characterisation and wettability studies. X-ray photoelectron spectroscopy measurements were performed to determine the cleaning and activation effects of the treatment. The strength of the bonded joint was studied for laser-treated and manually ground samples. Samples processed under the selected laser conditions exhibited better adhesive behaviour than the manually treated samples, thereby suggesting that ultraviolet laser treatment could be used as an alternative method for surface activation of aeronautical composites based on epoxy resins.

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