Fabienne Touchard, Michel Boustie, Laurence Chocinski-Arnault, Pedro Pascual González, Laurent Berthe, Davi de Vasconcellos, Luigi Sorrentino, Pawel Malinowski and Wieslaw Ostachowicz
The purpose of this paper is to study the damage induced in “green” and synthetic composites under impact loading.
Abstract
Purpose
The purpose of this paper is to study the damage induced in “green” and synthetic composites under impact loading.
Design/methodology/approach
The study was focussed on epoxy-based composites reinforced with woven hemp or glass fibres. Six assessment techniques were employed in order to analyse and compare impact damages: eye observation, back face relief, terahertz spectroscopy, laser vibrometry, x-ray micro-tomography and microscopic observations.
Findings
Different damage detection thresholds for each material and technique were obtained. Damage induced by mechanical and laser impacts showed relevant differences, but the damage mechanisms are similar in both types of impact: matrix cracks, fibre failure, debonding at the fibres/matrix interface and delamination. Damage shape on back surfaces is similar after mechanical or laser impacts, but differences were detected inside samples.
Originality/value
The combination of these six diagnoses provides complementary information on the damage induced by mechanical or laser impacts in the studied green and synthetic composites.
Details
Keywords
R. Ecault, M. Boustie, L. Berthe, F. Touchard, L. Chocinski-Arnault, H. Voillaume and B. Campagne
The purpose of this paper is to develop a laser shock adhesion test (LASAT) and evaluate its ability to reveal various bond qualities of stuck carbon fiber reinforced polymer…
Abstract
Purpose
The purpose of this paper is to develop a laser shock adhesion test (LASAT) and evaluate its ability to reveal various bond qualities of stuck carbon fiber reinforced polymer (CFRP) industrial assemblies.
Design/methodology/approach
Four grades of adhesion were prepared by release agent contamination of CFRP prior to assembly. Laser shots were performed at different intensities on these samples.
Findings
To characterize and quantify the damage created by the propagation of shock waves in the bonded material, several diagnoses were used (confocal microscopy, ultra-sound inspection and cross-sections microscopy). These three post-mortem techniques are complementary and provide consistent results.
Originality/value
The combination of these diagnoses along with the LASAT technique provides relevant information on the bond quality in agreement with GIC values measured by the University of Patras.
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Ch Kapil Ror, Vishal Mishra, Sushant Negi and Vinyas M.
This study aims to evaluate the potential of using the in-nozzle impregnation approach to reuse recycled PET (RPET) to develop continuous banana fiber (CBF) reinforced…
Abstract
Purpose
This study aims to evaluate the potential of using the in-nozzle impregnation approach to reuse recycled PET (RPET) to develop continuous banana fiber (CBF) reinforced bio-composites. The mechanical properties and fracture morphology behavior are evaluated to establish the relationships between layer spacing–microstructural characteristics–mechanical properties of CBF/RPET composite.
Design/methodology/approach
This study uses RPET filament developed from post-consumer PET bottles and CBF extracted from agricultural waste banana sap. RPET serves as the matrix material, while CBF acts as the reinforcement. The test specimens were fabricated using a customized fused deposition modeling 3D printer. In this process, customized 3D printer heads were used, which have a unique capability to extrude and deposit print fibers consisting of a CBF core coated with an RPET matrix. The tensile and flexural samples were 3D printed at varying layer spacing.
Findings
The Young’s modulus (E), yield strength (sy) and ultimate tensile strength of the CBF/RPET sample fabricated with 0.7 mm layer spacing are 1.9 times, 1.25 times and 1.8 times greater than neat RPET, respectively. Similarly, the flexural test results showed that the flexural strength of the CBF/RPET sample fabricated at 0.6 mm layer spacing was 47.52 ± 2.00 MPa, which was far greater than the flexural strength of the neat RPET sample (25.12 ± 1.94 MPa).
Social implications
This study holds significant social implications highlighting the growing environmental sustainability and plastic waste recycling concerns. The use of recycled PET material to develop 3D-printed sustainable structures may reduce resource consumption and encourages responsible production practices.
Originality/value
The key innovation lies in the concept of in-nozzle impregnation approach, where RPET is reinforced with CBF to develop a sustainable composite structure. CBF reinforcement has made RPET a superior, sustainable, environmentally friendly material that can reduce the reliance on virgin plastic material for 3D printing.
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Keywords
Ankang Liu, Bing Wang and Fei Li
This paper aims to study the effect of elevated temperature on the compression behaviour of carbon fibre polyphenylene sulphide (CF/PPS) laminates notched and unnotched specimens…
Abstract
Purpose
This paper aims to study the effect of elevated temperature on the compression behaviour of carbon fibre polyphenylene sulphide (CF/PPS) laminates notched and unnotched specimens made by film stacking method (FSM).
Design/methodology/approach
The surface of CF was coated with a silane coupling agent to form an effective transition layer with PPS, so as to enhance the interfacial interaction between CF and PPS. Considering the influence of fabrication pressure, forming temperature and cooling rate on the properties of laminates to obtain a reasonable preparation process. Conducting a compressive experiment of notched and unnotched specimens at different temperatures, which failure modes were examined by scanning electron microscope and stereo microscope.
Findings
The experimental observations highlight that with the increase of temperature, the transition failure mode from fibre broken to kink-band appeared in unnotched specimens, which were closely attributed to the matrix state. The notched specimens appeared more complex failure mode, which can be attributed to the joint effect of temperature and opening hole.
Research implications
A simple way of FSM for composite material laminates has been developed by using woven CF and PPS films.
Originality/value
The outcome of this study will help to understand the compression response mechanism of composite materials made by FSM at different temperature.
Details
Keywords
Vishal Mishra, Jitendra Kumar, Sushant Negi and Simanchal Kar
The current study aims to develop a 3D-printed continuous metal fiber-reinforced recycled thermoplastic composite using an in-nozzle impregnation technique.
Abstract
Purpose
The current study aims to develop a 3D-printed continuous metal fiber-reinforced recycled thermoplastic composite using an in-nozzle impregnation technique.
Design/methodology/approach
Recycled acrylonitrile butadiene styrene (RABS) plastic was blended with virgin ABS (VABS) plastic in a ratio of 60:40 weight proportion to develop a 3D printing filament that was used as a matrix material, while post-used continuous brass wire (CBW) was used as a reinforcement. 3D printing was done by using a self-customized print head to fabricate the flexural, compression and interlaminar shear stress (ILSS) test samples to evaluate the bending, compressive and ILSS properties of the build samples and compared with VABS and RABS-B samples. Moreover, the physical properties of the samples were also analyzed.
Findings
Upon three-point bend, compression and ILSS testing, it was found that RABS-B/CBW composite 3D printed with 0.7 mm layer width exhibited a notable improvement in maximum flexural load (Lmax), flexural stress at maximum load (sfmax), flex modulus (Ef) and work of fracture (WOF), compression modulus (Ec) and ILSS properties by 30.5%, 49.6%, 88.4% 13.8, 21.6% and 30.3% respectively.
Originality/value
Limited research has been conducted on the in-nozzle impregnation technique for 3D printing metal fiber-reinforced recycled thermoplastic composites. Adopting this method holds the potential to create durable and high-strength sustainable composites suitable for engineering applications, thereby diminishing dependence on virgin materials.
Details
Keywords
Magdalena Mieloszyk, Katarzyna Majewska and Wieslaw Ostachowicz
The purpose of this paper is to discuss the application of THz spectroscopy for the inspection and evaluation of the internal structure of complex samples with honeycomb fillers.
Abstract
Purpose
The purpose of this paper is to discuss the application of THz spectroscopy for the inspection and evaluation of the internal structure of complex samples with honeycomb fillers.
Design/methodology/approach
Three complex samples with honeycomb fillers are investigated using THz spectrometer in order to determine the applicability of chosen non-destructive method for the analysis of internal structure of structural components. The first analysed sample has aluminium honeycomb filler with some cells filled with water. The aim of the analysis is to distinguish empty and full cells. The other two sandwich samples are made of different non-metallic components and for them the possibility of THz spectroscopy application is analysed.
Findings
The empty and full cells in metal honeycomb filler were easily distinguished due to different absorption coefficients of electromagnetic waves in THz range for air and water. It was especially visible for frequency domain. The THz spectroscopy was able to inspect the non-metallic samples internal structures and distinguish skins (with layers), honeycomb fillers and adhesive layers between them. It was also possible to detect, localise and determine the size of a local damage of honeycomb walls due to impact influence.
Originality/value
The present study is an original research work. There are very limited literature papers which present analyses of internal structures of sandwich elements using THz spectroscopy and investigate utility of the method for mechanical damage and contamination (water) detection and localisation.
Details
Keywords
Vishal Mishra, Ch Kapil Ror, Sushant Negi and Simanchal Kar
This study aims to present an experimental approach to develop a high-strength 3D-printed recycled polymer composite reinforced with continuous metal fiber.
Abstract
Purpose
This study aims to present an experimental approach to develop a high-strength 3D-printed recycled polymer composite reinforced with continuous metal fiber.
Design/methodology/approach
The continuous metal fiber composite was 3D printed using recycled and virgin acrylonitrile butadiene styrene-blended filament (RABS-B) in the ratio of 60:40 and postused continuous brass wire (CBW). The 3D printing was done using an in-nozzle impregnation technique using an FFF printer installed with a self-modified nozzle. The tensile and single-edge notch bend (SENB) test samples are fabricated to evaluate the tensile and fracture toughness properties compared with VABS and RABS-B samples.
Findings
The tensile and SENB tests revealed that RABS-B/CBW composite 3D printed with 0.7 mm layer spacing exhibited a notable improvement in Young’s modulus, ultimate tensile strength, elongation at maximum load and fracture toughness by 51.47%, 18.67% and 107.3% and 22.75% compared to VABS, respectively.
Social implications
This novel approach of integrating CBW with recycled thermoplastic represents a significant leap forward in material science, delivering superior strength and unlocking the potential for advanced, sustainable composites in demanding engineering fields.
Originality/value
Limited research has been conducted on the in-nozzle impregnation technique for 3D printing metal fiber-reinforced recycled thermoplastic composites. Adopting this method holds the potential to create durable and high-strength sustainable composites suitable for engineering applications, thereby diminishing dependence on virgin materials.
Details
Keywords
Fabienne Touchard, Damien Marchand, Laurence Chocinski-Arnault, Teddy Fournier and Christophe Magro
Additive manufacturing is a recent technology used in the production of composite materials. The use of continuous fibres as reinforcement is necessary to achieve high mechanical…
Abstract
Purpose
Additive manufacturing is a recent technology used in the production of composite materials. The use of continuous fibres as reinforcement is necessary to achieve high mechanical performance. However, making these materials more environmentally friendly is still challenging. The purpose of this study was to investigate the feasibility of 3D printing a composite made of continuous regenerated cellulose fibres using a standard 3D printer generally used for printing polymers.
Design/methodology/approach
The production process was based on a pre-impregnated filament made from a tape containing continuous cellulose fibres and Pebax® matrix. 3D printed composite samples were fabricated using fused deposition modelling. The tape, filament and 3D printed composites were first analysed by means of modulated differential scanning calorimetry and micrography. Tensile tests were then performed, and the mechanical characteristics were determined at each step of the production process. Fracture surfaces were investigated by field-emission gun–scanning electron microscopy.
Findings
Results showed that the mechanical behaviour of the material was maintained throughout the production process, and the 3D printed biocomposites had a stiffness equivalent to that of traditionally manufactured continuous cellulose fibre composites. The obtained 3D printed composites showed an increase in strength value by a factor of 4 and in tensile modulus by a factor of 20 compared to those of unreinforced Pebax® polymer.
Originality/value
This paper demonstrates the feasibility of 3D printing composites based on continuous cellulose fibres, paving the way for new biocomposites made by additive manufacturing.
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Kawaljit Singh Randhawa and Ashwin Patel
The mechanical and tribological properties of polymers and polymer composites vary with different environmental conditions. This paper aims to review the influence of…
Abstract
Purpose
The mechanical and tribological properties of polymers and polymer composites vary with different environmental conditions. This paper aims to review the influence of humidity/water conditions on various polymers and polymer composites' mechanical properties and tribological behaviors.
Design/methodology/approach
The influence of humidity and water absorption on mechanical and tribological properties of various polymers, fillers and composites has been discussed in this paper. Tensile strength, modulus, yield strength, impact strength, COF and wear rates of polymer composites are compared for different environmental conditions. The interaction between the water molecules and hydrophobic polymers is also represented.
Findings
Pure polymer matrices show somewhat mixed behavior in humid environments. Absorbed moisture generally plasticizes the epoxies and polyamides and lowers the tensile strength, yield strength and modulus. Wear rates of PVC generally decrease in humid environments, while for polyamides, it increases. Fillers like graphite and boron-based compounds exhibit low COF, while MoS2 particulate fillers exhibit higher COF at high humidity and water conditions. The mechanical properties of fiber-reinforced polymer composites tend to decrease as the rate of humidity increases while the wear rates of fiber-reinforced polymer composites show somewhat mixed behavior. Particulate fillers like metals and advanced ceramics reinforced polymer composites exhibit low COF and wear rates as the rate of humidity increases.
Originality/value
The mechanical and tribological properties of polymers and polymer composites vary with the humidity value present in the environment. In dry conditions, wear loss is determined by the hardness of the contacting surfaces, which may not effectively work for high humid environments. The tribological performance of composite constituents, i.e. matrix and fillers in humid environments, defines the overall performance of polymer composite in said environments.
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The QUALCAT project at the University of Bradford attempted to apply automated quality control to databases of bibliographic records. Sets of records, putative duplicates, that…
Abstract
The QUALCAT project at the University of Bradford attempted to apply automated quality control to databases of bibliographic records. Sets of records, putative duplicates, that appeared to be for the same monograph were grouped together and an expert system used to determine whether they were in fact duplicates, and if so which were the best records. This paper outlines the expert system used and discusses problems and further developments in automated examination of bibliographic records.