3D PRINTED CONTINUOUS FIBRE COMPOSITE RESEARCH AT DEAKIN UNIVERSITY: DESIGN AND ANALYSIS METHODS FOR UD, HYBRID AND PSEUDO-WOVEN PLY ARCHITECTURES

2021 ◽  
Author(s):  
MATHEW JOOSTEN ◽  
ZI LI ◽  
CHENG HUANG

At Deakin University we have been researching the performance of continuous fibre 3D printed composite structures and a summary of three research activities related to this research theme are provided herein. 3D printed continuous fibre composites can be used to realise significant gains in stiffness and strength compared to an equivalent component fabricated using a neat thermoplastic. To investigate the performance of these materials both commercially available and customised printers were used to fabricate composite laminates and the behaviour of these laminates evaluated experimentally. Finite element and analytical models were used to predict the mechanical response. These approaches were originally developed for thermoset matrices, however, the models have shown to be capable of predicting the behaviour of 3D printed carbon fibre and hybrid carbon-fibreglass thermoplastic composites. These validated models can be used to generate design charts to identify feasible UD and semi-woven textile architectures, thereby, allowing designers to tailor the ply architecture and stacking sequence to meet specific design requirements.

2019 ◽  
Vol 26 (3) ◽  
pp. 549-555
Author(s):  
Jin Young Choi ◽  
Mark Timothy Kortschot

Purpose The purpose of this study is to confirm that the stiffness of fused filament fabrication (FFF) three-dimensionally (3D) printed fiber-reinforced thermoplastic (FRP) materials can be predicted using classical laminate theory (CLT), and to subsequently use the model to demonstrate its potential to improve the mechanical properties of FFF 3D printed parts intended for load-bearing applications. Design/methodology/approach The porosity and the fiber orientation in specimens printed with carbon fiber reinforced filament were calculated from micro-computed tomography (µCT) images. The infill portion of the sample was modeled using CLT, while the perimeter contour portion was modeled with a rule of mixtures (ROM) approach. Findings The µCT scan images showed that a low porosity of 0.7 ± 0.1% was achieved, and the fibers were highly oriented in the filament extrusion direction. CLT and ROM were effective analytical models to predict the elastic modulus and Poisson’s ratio of FFF 3D printed FRP laminates. Research limitations/implications In this study, the CLT model was only used to predict the properties of flat plates. Once the in-plane properties are known, however, they can be used in a finite element analysis to predict the behavior of plate and shell structures. Practical implications By controlling the raster orientation, the mechanical properties of a FFF part can be optimized for the intended application. Originality/value Before this study, CLT had not been validated for FFF 3D printed FRPs. CLT can be used to help designers tailor the raster pattern of each layer for specific stiffness requirements.


2012 ◽  
Vol 24 (8) ◽  
pp. 991-1006 ◽  
Author(s):  
Oliver J Myers ◽  
George Currie ◽  
Jonathan Rudd ◽  
Dustin Spayde ◽  
Nydeia Wright Bolden

Defects in composite laminates are difficult to detect because of the conductive and paramagnetic properties of composite materials. Timely detection of defects in composite laminates can improve reliability. This research illustrates the preliminary analysis and detection of delaminations in carbon fiber laminate beams using a single layer of magnetostrictive particles and noncontacting concentric magnetic excitation and sensing coils. The baseline analytical models also begin to address the intrusive nature of the magnetostrictive particles as well as relate the applied excitation field with the stress and magnetic flux densities induced in the magnetostrictive layer. Numerical methods are used to begin to characterize the presence of magnetostrictive particles in the laminate and the behavior of the magnetostrictive particles in relationship to the magnetic field used during sensing. Unidirectional laminates with embedded delaminations are used for simulations and experimentations. A novel, yet simplified fabrication method is discussed to ensure consistent scanning and sensing capabilities. The nondestructive evaluation scanning experiments were conducted with various shapes and sizes of damages introduced into carbon fiber–reinforced polymeric composite structures. The results demonstrate high potential for magnetostrictive particles as a low-cost, noncontacting, and reliable sensor for nondestructive evaluation of composite materials.


2016 ◽  
Vol 30 (12) ◽  
pp. 1693-1712 ◽  
Author(s):  
Suong Van Hoa ◽  
Minh Duc Hoang ◽  
Jeff Simpson

Automated fibre placement (AFP) is a relatively new process for the manufacturing of composite structures. Among many attractive features, it provides high-speed of material deposition, more repeatability in terms of quality of the part, less labour intensive (as compared with traditional methods of manufacturing such as Hand Lay-Up), less waste and the ability to transition more seamlessly from design to manufacturing. AFP can be used to process both thermoset composites and thermoplastic composites. Thermoplastic composites processing holds many potential benefits. This is because if the process is done right in producing parts with good quality, it is fast since it does not require a second process such as curing in an autoclave or oven. For the purpose of comparison of performance and for design, it is necessary to determine the mechanical properties of laminates made using this process. However, there are challenges in making flat coupons for the purpose of testing for mechanical properties. This article presents these challenges and the procedure developed to make flat laminates using a simple AFP machine. Mechanical properties of these laminates are also determined and compared with those obtained from laminates made using conventional autoclave moulding.


2021 ◽  
pp. 002199832110316
Author(s):  
Mohammadhossein Ghayour ◽  
Mehdi Hojjati ◽  
Rajamohan Ganesan

Automated manufacturing defects are new types of composite structure defects induced during fiber deposition by robots. Fiber tow gap is one of the most probable types of defects observed in the Automated Fiber Placement (AFP) technique. This defect can affect the structural integrity of structures by reducing structural strength and stiffness. The effect of this defect on the mechanical response of the composite laminates has been investigated experimentally in the literature. However, there is still no efficient numerical/analytical method for damage assessment of composite structures with distributed induced gaps manufactured by the AFP technique. The present paper aims to develop the Induced Defect Layer Method (IDLM), a new robust meso-macro model for damage analysis of the composite laminates with gaps. In this method, a geometrical parameter, Gap Percentage (GP), is implemented to incorporate the effect of induced-gaps in the elastic, inelastic, and softening behavior at the material points. Thus, while the plasticity and failure of the resin pockets in conjunction with intralaminar composite damages can be evaluated by this method, the defective areas are not required to be defined as resin elements in the Finite Element (FE) models. It can also be applied for any arbitrary distributions of the defects in the multi-layer composite structures, making it a powerful tool for continuum damage analysis of large composite structures. Results indicate that the proposed method can consider the effect of gaps in both elastic and inelastic behavior of the composite laminate with defects. It also provides good agreement with the experimental results.


2012 ◽  
Vol 245 ◽  
pp. 316-322
Author(s):  
Ramadan A. Al-Madani ◽  
M. Jarnaz ◽  
K. Alkharmaji ◽  
M. Essuri

The characteristics of composite materials are of high importance to engineering applications; therefore the increasing use as a substitute for conventional materials, especially in the field of aircraft and space industries. It is a known fact that researchers use finite element programs for the design and analysis of composite structures, use of symmetrical conditions especially in complicated structures, in the modeling and analysis phase of the design, to reduce processing time, memory size required, and simplifying complicated calculations, as well as considering the response of composite structures to different loading conditions to be identical to that of metallic structures. Finite element methods are a popular method used to analyze composite laminate structures. The design of laminated composite structures includes phases that do not exist in the design of traditional metallic structures, for instance, the choice of possible material combinations is huge and the mechanical properties of a composite structure, which are anisotropic by nature, are created in the design phase with the choice of the appropriate fiber orientations and stacking sequence. The use of finite element programs (conventional analysis usually applied in the case of orthotropic materials) to analysis composite structures especially those manufactured using angle ply laminate techniques or a combination of cross and angle ply techniques, as well considering the loading response of the composite structure to be identical to that of structures made of traditional materials, has made the use of, and the results obtained by using such analysis techniques and conditions questionable. Hence, the main objective of this paper is to highlight and present the results obtained when analyzing and modeling symmetrical conditions as applied to commercial materials and that applied to composite laminates. A comparison case study is carried out using cross-ply and angle-ply laminates which concluded that, if the composition of laminate structure is pure cross-ply, the FEA is well suited for predicting the mechanical response of composite structure using principle of symmetry condition. On the other hand that is not the case for angle-ply or mixed-ply laminate structure.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2450
Author(s):  
Andreas Borowski ◽  
Christian Vogel ◽  
Thomas Behnisch ◽  
Vinzenz Geske ◽  
Maik Gude ◽  
...  

Continuous carbon fibre-reinforced thermoplastic composites have convincing anisotropic properties, which can be used to strengthen structural components in a local, variable and efficient way. In this study, an additive manufacturing (AM) process is introduced to fabricate in situ consolidated continuous fibre-reinforced polycarbonate. Specimens with three different nozzle temperatures were in situ consolidated and tested in a three-point bending test. Computed tomography (CT) is used for a detailed analysis of the local material structure and resulting material porosity, thus the results can be put into context with process parameters. In addition, a highly curved test structure was fabricated that demonstrates the limits of the process and dependent fibre strand folding behaviours. These experimental investigations present the potential and the challenges of additive manufacturing-based in situ consolidated continuous fibre-reinforced polycarbonate.


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