Automated Manufacture of Advanced Composites (AMAC)

In this work, the influence of AFP process parameters and their interactions on the interlaminar shear strength (ILSS) of CF-PEEK composites was investigated. Experimental short beam shear (SBS) tests and FEA numerical simulations with bonding models were conducted to generate data. Various process parameter combinations were analyzed using full-factorial statistical assessment. Results show that ILSS increases with decreasing deposition speeds and increasing HGT temperatures, with consolidation forces having a milder effect. A strong interaction effect between parameters was observed, and the effect of HGT temperature on ILSS depends on material deposition speed. The optimum ILSS were at low deposition speeds (76 mm/s) with high HGT temperatures (900 °C or 950 °C), also evident in the fracture surfaces. This database can aid smart production planning in additive manufacturing of composites by optimizing process parameters for maximum interlaminar strength. Faisal Islam, Ebrahim Oromiehie, Andrew W. Phillips, Nigel A. St John, Prof Gangadhara Prusty Paper Title: Data-driven optimization of additive composite manufacturing using automated fibre placement: A study on process parameters effects and interactions Journal: Composites Part A: Applied Science and Manufacturing Paper access: https://lnkd.in/gmdWQcKx UNSW Mechanical and Manufacturing Engineering, Automated Manufacture of Advanced Composites (AMAC), Defence Science and Technology Group (DSTG), ACM CRC ThermoplasticCFRP; composites; Shearstrength; Automatedfibreplacement; Automatedcompositesmanufacturing;

Automated fibre placement (AFP) can optimise material usage in composite pressure vessels, which are commonly used for hydrogen storage. In our latest work, we have investigated how non-geodesic fibre paths and thickness optimisation leveraging the flexibility of AFP can reduce the mass and size of a pressure vessel dome. We found considerable improvements in these metrics with a combination of finite element analysis, AFP manufacturing, and hydrostatic pressure testing and identified process limitations that can be targeted in future work. Alex Air, Ebrahim Oromiehie, Prof Gangadhara Prusty Paper Title: Optimisation of a composite pressure vessel dome using non-geodesic fibre paths and automated fibre placement manufacturing Journal: Composites Part B: Engineering Paper access: https://lnkd.in/gNpZM3y3 UNSW Mechanical and Manufacturing Engineering, Automated Manufacture of Advanced Composites (AMAC), ACM CRC #Carbonfibre; #Mechanicalproperties; #Finiteelementanalysis; #Automation; #Compositepressurevessel

🔍 New Economic Impact Analysis of Automated Manufacture of Advanced Composites (AMAC) Centre Projects Released! 📊 I’m excited to share the results of our latest independent Economic Impact Analysis for our key 4 projects by ACIL Allen. This analysis has highlighted some remarkable contributions to the Australian Transportation, Defence, Health and Infrastructure sectors with far-reaching effects on job creation, industry innovation, and community development. 🌱 Key Takeaways of the AMAC Centre: Created 61 funded projects with 52 collaborations/partnerships 23 PhDs graduated and many more in process Published 109 Q1 journals and 35 international conference papers 3 spin-off companies and 3 patents Enabled ACM CRC, a $250 M project for next 10 years Our AMAC team and industry partners have worked diligently to gather this data, and the findings demonstrate the real-world value of our research beyond the academic sphere. A big thank you to everyone involved in making this project a success! Prof Gangadhara Prusty, UNSW, UNSW Engineering, UNSW Mechanical and Manufacturing Engineering, SDI Limited , Defence Science and Technology Group (DSTG), Omni Tanker Pty Ltd, Transport for NSW. Australian Research Council, ACM CRC, Department of Industry, Science and Resources #EconomicImpact #ResearchMatters #Innovation #CommunityDevelopment #ResearchImpact

Our new paper focuses on the in-situ consolidation of thermoplastic composites using Automated Fibre Placement (AFP) technology is an emerging manufacturing technique, offering tailored composite properties through customised processing parameters. Multiple competing parameters during AFP manufacturing influence the quality and mechanical performance of the laminates. These lay-up parameters are interrelated, and often require comprehensive experimental characterisation which is costly and time-intensive. This study aims to optimise the fracture toughness of in-situ consolidated thermoplastic composite (AS4/APC-2) and investigate the mechanisms that contribute to it. Taguchi’s method is employed to efficiently analyse the effect of various process parameters at multiple levels. Based on the obtained results, a considerable effect of process parameters on Mode I and II fracture toughness is observed. The statistical analysis reveals that the Hot Gas Torch (HGT) temperature required for AFP processing significantly affects the Mode I fracture toughness, contributing to 33.8%. Whereas, the consolidation force, another key processing parameter in AFP notably affects Mode II fracture toughness, with the contribution of 81.8%. The analysis of variance (ANOVA) reveals interdependent processing parameter relations for both fracture modes. A validation test showed good agreement between the predicted fracture toughness and the experimental test. Shafaq ., Matthew Donough, Ph.D., Ebrahim Oromiehie, Faisal Islam, Dr. Andrew W Phillips, Dr. Nigel St. John, Prof Gangadhara Prusty Paper Title: Parametric process optimisation of automated fibre placement (AFP) based AS4/APC-2 composites for mode I and mode II fracture toughness Journal: Journal of Composite Materials Paper access: https://lnkd.in/gHDGbEti UNSW Engineering, UNSW Mechanical and Manufacturing Engineering, Automated Manufacture of Advanced Composites (AMAC), ACM CRC, Defence Science and Technology Group (DSTG) #Automatedfibreplacement; #polymermatrixcomposites; #fracturetoughness; #crystallinity' #statisticalanalysis; #taguchimethod

Exciting paper published on Acoustic Emission: This study explores the use of stress waves for non-destructive inspection and structural health monitoring in large laminated composite panels. It examines Lamb wave dispersion under two boundary conditions (fixed and simply supported) and two scenarios: a 100 kHz excitation simulating internal defects and a 30 N impulse load representing external events, both with and without cutouts. Experimental and numerical analyses are conducted to investigate wave propagation characteristics, with a focus on the time delays caused by cutouts. Results show that cutouts disrupt the propagation path, leading to significant time discrepancies. The numerical model's findings closely match the experimental results, demonstrating the effectiveness of stress waves for inspecting and monitoring laminated composites. Binayak Bhandari, Ph.D., Phyo Thu Maung and Prof Gangadhara Prusty Paper Title: Numerical model and experimental validation of stress waves propagation in large composite panels Journal: Journal of Reinforced Plastics and Composites Paper access: https://lnkd.in/gibgBvyD UNSW Engineering, UNSW Mechanical and Manufacturing Engineering, Automated Manufacture of Advanced Composites (AMAC), ACM CRC #LambWave; #LaminatedCompositeStructures; #NonDestructivetesting; #AcousticEmissions; #NumericalModelling; #StructuralHealthMonitoring

Our new paper published on Pressure vessel manufacturing and integrated SHM In recent years, the mobility (air/land) industry has been developing fuel-cell vehicles for mass adoption as hydrogen technology matures. Compared to conventional metallic design, the composite overwrapped pressure vessel without a metal or polymer liner results in a lightweight solution for gaseous hydrogen storage which further improves fuel efficiencies. Since the capabilities of automated fiber placement for making multi-stiffened structures are distinct from other automated manufacturing techniques, this study aimed to evaluate the feasibility of implementing AFP into the manufacture of a small scale COPV with a partially composite liner. The manufacturing related challenges are identified and discussed. During the manufacturing process, Distributed fiber optic sensor was embedded between the plies, as a structural health monitoring solution, to monitor the mechanical performance of the pressurized tank. In addition, finite element study was done to predict the internal strains for different pressure levels and the measured experimental strains at the sensor's location are found to be in close agreement with the finite element results. It is shown that such sensors can be integrated into automated fiber placement manufactured tanks for internal strain monitoring. Ebrahim Oromiehie, Prashanth Nagulapally, Matthew Donough, Ph.D., Prof Gangadhara Prusty Title: Automated manufacture and experimentation of composite overwrapped pressure vessel with embedded optical sensor Journal: International Journal of Hydrogen Energy Paper access: https://lnkd.in/gmd_HcW5 UNSW Engineering, Automated Manufacture of Advanced Composites (AMAC), ACM CRC #Automatedfiberplacement; #CFRPcomposites; #Compositeoverwrappedpressurevessels; #Structuralhealthmonitoring

Our new paper on composites damage detection on Acoustic Emission: The Time Difference Of Arrival (TDOA) method has traditionally proven effective for locating acoustic emission (AE) sources and detecting structural defects. Nevertheless, its applicability is constrained when applied to anisotropic materials, particularly in the context of fiber-reinforced composite structures. In response, this paper introduces a novel COmposite LOcalization using Response Surface (COLORS) algorithm based on a two-step approach for precise AE source localization suitable for laminated composite structures. Leveraging a response surface developed from critical parameters, including AE velocity profiles, attenuation rates, distances, and orientations, the proposed method offers precise AE source predictions. The incorporation of updated velocity data into the algorithm yields superior localization accuracy compared to the conventional TDOA approach relying on the theoretical AE propagation velocity. The mean absolute error (MAE) for COLORS and TDOA were found to be 6.97 mm and 8.69 mm, respectively. Similarly, the root mean square error (RMSE) for COLORS and TODA methods were found to be 9.24 mm and 12.06 mm, respectively, indicating better performance of the COLORS algorithm in the context of source location accuracy. The finding underscores the significance of AE signal attenuation in minimizing AE wave velocity discrepancies and enhancing AE localization precision. The outcome of this investigation represents a substantial advancement in AE localization within laminated composite structures, holding potential implications for improved damage detection and structural health monitoring of composite structures. Binayak Bhandari, Ph.D., Phyo Thu Maung and Prof Gangadhara Prusty Paper Title: Novel Response Surface Technique for Composite Structure Localization Using Variable Acoustic Emission Velocity Journal: MDPI Sensors Paper access: https://lnkd.in/gEh6ic3a UNSW Engineering, Automated Manufacture of Advanced Composites (AMAC), ACM CRC #acousticemission; #compositelaminates; #localization; #least-squaremethod; #responsesurface; #velocityattenuation; #timedifferenceofarrival

Glad to update about our new paper in Composites Part A: Applied Science and Manufacturing: This collaborative, French-Australian research campaign investigated the combined effects of low-velocity impact damage, and subsequent hydrothermal ageing in seawater (4 months at 60°C), on the residual compressive strength of 4 mm thick CF/epoxy laminates. The new compression after impact after ageing (CAAAI) methodology builds on the existing compression after impact (CAI) (ISO ASTM D7137) standard established by the aerospace industry and sets the foundations for the impact damage assessment of advanced composite materials which are more relevant to the marine environment. Rowan Caldwell, Peter Davies, Mael Arhant and Prof Gangadhara Prusty Journal: Composites Part A: Applied Science and Manufacturing Paper title: Compression and hydrothermal ageing after impact of carbon fibre reinforced epoxy laminates Paper access: https://lnkd.in/gM_GKAtz UNSW Engineering, Automated Manufacture of Advanced Composites (AMAC), ACM CRC, INSTITUT FRANCAIS DE RECHERCHE POUR L'EXPLOITATION DE LA MER - IFREMER #Carbonfibre; #Thermosettingresin; #Damagetolerance; #Impactbehaviour; #Moisture

Happy to let you know a new book chapter is published. Title: Carbon Fibre Reinforced Polymer Composite Retrofitted Steel Profiles Using Automated Fibre Placement Book: RC Structures Strengthened with FRP for Earthquake Resistance DOI: https://lnkd.in/gQVnbQCj Book chapter access:https://lnkd.in/gS6jJ8M3 Abstract: Traditional methods for repairing impaired structures such as concreting, steel jackets, or timber splicing are impractical because of the inherent constraints associated with these materials. They would be susceptible to the same deterioration as the existing structure, leading to an ongoing cycle of repairs. Fibre-reinforced polymer (FRP) composite jackets offer a wide range of advantages including superior corrosion resistance, lightweight properties, and long-lasting durability. These characteristics make FRP composite jackets highly advantageous compared to conventional repair systems. Additionally, they can be effectively utilized for repairing various types of structures, including those made of timber, steel, and concrete. FRP composite jackets can be implemented through several techniques. However, in the experimental investigation presented in this chapter, automated fibre placement (AFP) was used to overwrap and reinforce two sets of thin-walled square hollow sections (SHS), columns and beams, with thermoplastic carbon fibre reinforced polymer (CFRP). The results obtained were then compared with the control samples without CFRP reinforcement. For the control columns, a good agreement was observed between the predicted and experimental ultimate compressive loads. The ultimate loads of CFRP reinforced columns exceeded the ultimate loads of the control columns. Inward and outward buckling was observed in each column. De-bonding, tearing, and snapping of the CFRP plies was observed in column specimens with thermoplastic CFRP reinforcement. For the control beams, there was a comparable agreement between the predicted ultimate load and the experimental ultimate load. It was found that the ultimate loads for some strengthened beams were higher than that of the control beams. For all beams, there was inward deformation on the upper surface of each beam, and outward deformations were observed on the two side walls of the SHS beams. This experimental investigation showed that the current strengthening processes using AFP is not comparable to traditional CFRP strengthening methods which use epoxy and FRP plies and that further research is required in this space. Due to the failure modes observed, future research is planned to improve the reinforcement method using AFP. The planned improvements are surface preparation, AFP processing conditions, number of CFRP layers and orientation of the CFRP. Ebrahim Oromiehie, Dr. Feleb Matti, Fidelis Mashiri, Prof Gangadhara Prusty UNSW Engineering, Automated Manufacture of Advanced Composites (AMAC), ACM CRC, Western Sydney University

We are glad to let you know that new paper has been published titled 'Nanostructure characterisation of welded polyethylene using small angle X-ray scattering' Polyethylene (PE), a common thermoplastic polymer, is gaining prominence in the construction and packaging industries due to its exceptional mechanical properties, chemical resistance, safety, and integrity. However, internal defects can occur during manufacturing and throughout its service life. Neglecting this problem results in the disposal of plastic and, consequently, the accumulation of plastic waste and environmental issues, which have caused much criticism. A common method to repair the thermoplastics is welding, which introduces seams and localized thermal residual stress fields resulting in areas where damage can nucleate, potentially leading to cracks and failure over time. These cracks often start at the nanoscale and propagate to larger length scales until failure occurs. The objective of this research paper is to develop welding processes, with improved integrity and lifespan for PE. Additionally, it aims to investigate and assess the impact of PE welding on parent materials at nano- and micron-scales, to understand limitations that are challenging to overcome in such welding processes. The study involves joining PE panels together under various pre-heating and post-cooling conditions, followed by evaluating the environmental stress cracking resistance of the welds and the durability of the repaired components. The crystallinity and morphology of the PE material in the weld area and its surrounding regions were analysed using Small Angle X-ray Scattering (SAXS), and the findings were compared with results obtained from optical microscopy and Differential Scanning Calorimetry. The study concludes that SAXS results offer exceptional information about the parent PE and weld material within the welding zone. Ebrahim Oromiehie, Adrian Kong, Luke Djukic, Jitendra Mata, Daniel Rodgers, Prof Gangadhara Prusty Title: Nanostructure characterisation of welded polyethylene using small angle X-ray scattering Journal: Journal of Reinforced Plastics and Composites Paper access: https://lnkd.in/gjxYUUBi UNSW Engineering, Automated Manufacture of Advanced Composites (AMAC), ACM CRC #Thermoplastics; #Polyethylene, #Crystallinity, #SmallangleX-rayscattering