Research overview: Our research concerns at the understanding, predicting and optimising the mechanical response of composite materials via experimental, analytical and computational efforts. We aim at developing high fidelity models that can predict material performance and provide fundamental insight in a wide range of multidisciplinary challenges, from carbon fibre composites to carbon nanotube composites, from macro-scale to nano-scale, from mono-functional to multi-functional applications. Particularly, these research projects include:

(1) proposing novel characterisation method to reveal the microstructures and deformation/failure mechanisms of composites operating over different length scale;

(2) developing novel, robust and efficient models for the mechanical response of composites under impact or crush loading;

(3) promoting a new generation of damage tolerant and multifunctional composites using carbon nanotube materials.

Research interests:

(1) Mechanics of Composite Materials: plasticity, fracture, fatigue modelling of composite materials.

(2) Multifunctional composites for energy storage, shape-morphing and sensing.

(3) Data-driven modelling of composite materials.

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Research highlights:

(1) Impact and crush behaviour of carbon fibre composites

Research summary:

Composite structures are susceptible to impact damage, which requires costly and highly inefficient experimental testing to meet safety-critical certification. My project aimed to develop a predictive material model for capturing impact damage and energy absorption capacity of CFRP.

1) A multiscale model was also proposed to take into account the physical mechanisms of deformation at different length scales of composite structures. This efficient strategy enables carrying out multiscale modelling from the properties of the constituents (fibre, matrix and interfaces) and homogenise the results into a constitutive model, followed by the transfer of information to the next length scale, which is both time-saving and economical for industry.

2) A physically-based model based on crystal plasticity has been proposed to accurately capture the inelastic behaviour and strain rate effect of composites subjected to shear or compressive or impact loading.

3) Low-velocity impact damage can drastically reduce the residual strength of a composite structure even when the damage is barely visible. The ability to computationally predict the extent of damage and compression-after-impact (CAI) strength of a composite structure can potentially lead to the exploration of a larger design space without incurring significant time and cost penalties. A high-fidelity three-dimensional composite damage model, to predict both low-velocity impact damage and CAI strength of composite laminates, has been developed and implemented as a user material subroutine in the commercial finite element package, ABAQUS/Explicit. 

4) A crushing model based on a new distorted element deletion strategy was presented to capture the crushing behaviour of composite materials.  This model solves the convergence issue due to element distortion under large deformation via deleting element based on the determinant of deformation gradient.  

Reference papers:

• Cheng ZQ, Tan W, Xiong JJ (2022). “Modelling Pre-fatigue, Low-velocity Impact and Post-impact Fatigue Behaviours of Composite Helicopter Tail Structures under Multipoint Coordinated Loading Spectrum.” Elsevier  Thin-Walled Structures DOI10.1016/j.tws.2022.109349
• Wang X, Li P, Xiang D, Wang B, Zhang Z, Zhang J, Zhao C, Li H, Tan W, Wang J and Li Y (2022). “Influence of high-temperature, high-pressure, and acidic conditions on the structure and properties of high-performance organic fibers.” Materialpruefung/Materials Testing vol. 64 (5), 623-635. DOI10.1515/mt-2021-2099
• Tan W and Martínez-Pañeda E (2022). “Phase field fracture predictions of microscopic bridging behaviour of composite materials.” Elsevier  Composite Structures vol. 286 DOI10.1016/j.compstruct.2022.115242
• Cheng, Z.Q., Xiong, J.J. and Tan W*, 2021. Fatigue Crack Growth and Life Prediction of 7075-T62 Aluminium-alloy Thin-sheets with Low-velocity Impact Damage under Block Spectrum Loading. International Journal of Fatigue, p.106618. https://doi.org/10.1016/j.ijfatigue.2021.106618.
• Cheng ZQ, Tan W and Xiong JJ (2021). “Progressive damage modelling and fatigue life prediction of Plain-weave composite laminates with Low-velocity impact damage.” Composite Structures  vol. 273, DOI10.1016/j.compstruct.2021.114262
• Tan W and Martínez-Pañeda E (2020). “Phase field predictions of microscopic fracture and R-curve behaviour of fibre-reinforced composites.” Elsevier Bv  Composites Science and Technology  108539-108539. DOI10.1016/j.compscitech.2020.108539
• Tan W and Liu B (2020). “A physically-based constitutive model for the shear-dominated response and strain rate effect of carbon fibre reinforced composites.”, Editors: Wang H. Elsevier  Composites Part B: Engineering  DOI10.1016/j.compositesb.2020.108032
• Tan W, Naya F, Yang L, Chang T, Falzon BG, Zhan L, Molina-Aldareguía JM, González C and Llorca J (2018). “The role of interfacial properties on the intralaminar and interlaminar damage behaviour of unidirectional composite laminates: Experimental characterization and multiscale modelling.” Composites Part B: Engineering  vol. 138, 206-221. DOI10.1016/j.compositesb.2017.11.043
• Tan W and Falzon BG (2016). “Modelling the crush behaviour of thermoplastic composites.” Elsevier  Composites Science and Technology  vol. 134, 57-71. DOI10.1016/j.compscitech.2016.07.015
• Tan W, Falzon BG, Price M and Liu H (2016). “The role of material characterisation in the crush modelling of thermoplastic composite structures.” Composite Structures  vol. 153, 914-927. DOI10.1016/j.compstruct.2016.07.011
• Tan W and Falzon BG (2016). “Modelling the nonlinear behaviour and fracture process of AS4/PEKK thermoplastic composite under shear loading.” Elsevier  Composites Science and Technology  vol. 126, 60-77. DOI10.1016/j.compscitech.2016.02.008
• Tan W, Falzon BG, Chiu LNS and Price M (2015). “Predicting low velocity impact damage and Compression-After-Impact (CAI) behaviour of composite laminates.” Composites Part a: Applied Science and Manufacturing  vol. 71, 212-226. DOI10.1016/j.compositesa.2015.01.025
• Tan W, Falzon BG and Price M (2015). “Predicting the crushing behaviour of composite material using high-fidelity finite element modelling.” International Journal of Crashworthiness  vol. 20, (1) 60-77. DOI10.1080/13588265.2014.972122

Example: Predicting the crushing process of thermoplastic composites

Example: High-velocity impact response of a carbon nanotube mat

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(2) Mechanics of direct-spun carbon nanotube mat and composites

Research summary:

CNT with superior structural, electrical and thermal properties, is of great potential to introduce multi-functionalities to CFPR, such as impact-tolerance, lightning strike protection and de-icing. Cambridge University has first proposed floating catalyst chemical vapour deposition method (FFCVD) to produce macroscopic CNT fibres/mats continuously in large volume (500 m2/day).   However, the properties of macroscopic CNT fibres/mats haven’t yet reached the full potential of individual CNT (only 1% at present). To understand the properties of macroscopic CNT sheet, I have developed various novel characterisation and computational methods.

1) Achieved the first in-situ microscopy that reveals the deformation mechanisms of CNT mat.  We found that CNT bundles form random interlinked bundle networks and the network deforms like a foam under tension, with dominant transverse deflection of struts. The lack of stretching on CNT bundles limits the macroscopic mechanical properties of CNT mat. 

2) Elemental mapping of CNT-epoxy composite firstly revealed that epoxy resin does not penetrate CNT bundle. Consequently, the interfacial properties between individual CNTs are not improved. This explains the limitation of epoxy in the enhancement of CNT performance.

3) Proposed a novel micromechanical model to relate macroscopic CNT mat properties to those of CNT bundle network and CNT-epoxy composites. The model was able to describe the degree of elastic and plastic anisotropy of the composite and the dependence of modulus and yield strength upon composition. I also developed a special four-point probe system to measure the electrical conductivity of CNT-epoxy composites, eliminating the contact and wire resistance. A novel steady-state method using an infrared camera to measure thermal conductivity of CNT-epoxy composite under vacuum was also presented. These results found that the electrical and thermal conductivities of CNT-epoxy composite is primarily dependent on the CNT volume fraction.

References:

• Gspann TS, Kaniyoor A, Tan W, Kloza PA, Bulmer JS, Mizen J, Divitini G, Terrones J, Tune D, Cook JD, Smail FR and Elliott JA (2021). “Catalyst-Mediated Enhancement of Carbon Nanotube Textiles by Laser Irradiation: Nanoparticle Sweating and Bundle Alignment.” Mdpi Ag  Catalysts  vol. 11, (3) 368-368. DOI10.3390/catal11030368
• Tan W, Stallard JC, Smail FR, Boies AM and Fleck NA (2019). “The mechanical and electrical properties of direct-spun carbon nanotube mat-epoxy composites.” Carbon  vol. 150, 489-504. DOI10.1016/j.carbon.2019.04.118
• Stallard JC, Tan W, Smail FR, Gspann TS, Boies AM and Fleck NA (2018). “The mechanical and electrical properties of direct-spun carbon nanotube mats.” Extreme Mechanics Letters  vol. 21, 65-75. DOI10.1016/j.eml.2018.03.003
  01-05-2018

Example: Mass production of direct-spun carbon nanotube mat (Tortech)

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(3) Mechanics of carbon nanotube polyaniline composites for energy storage

Research Summary:

Novel direct-spun carbon nanotube polyaniline composite electrodes are developed for supercapacitor applications. Supercapacitors combine high specific power with cyclic stability. Consequently, they find application in regenerative braking systems and in other applications that require high power, short-term energy storage. The influence of charge and discharge rate, electrode composition and state of charge upon the mechanical and electrochemical properties of these novel electrode composites is currently unclear, as are the mechanisms of degradation upon cycling and pre-charging. These topics are addressed in our study.

References:

• Koliolios, E., Mills, D. G., Busfield, J. J., & Tan W*. (2021). The Nail Penetration Behaviour of Carbon Nanotube Composite Electrodes for Energy Storage. Frontiers in Materials, 429. https://doi.org/10.3389/fmats.2021.741541.
• Tan W, Stallard JC, Jo C, De Volder MFL and Fleck NA (2021). “The mechanical and electrochemical properties of polyaniline-coated carbon nanotube mat.” Journal of Energy Storage  vol. 41, DOI10.1016/j.est.2021.102757

Example: RECHARGEABLE Supercapacitor Tram

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(4) Data-driven modelling of composite materials

Research summary:

The adoption of cellular structures for applications involving crash energy absorption are increasing due to their beneficial mechanical properties including low weight and high specific energy absorption. This project aims to integrate the data-driven approach and finite element modelling for designing energy-absorbing composite materials.

References:

• Khosroshahi Siamak, Hirak, K., Miguel, B. & Tan, W. Data-driven framework for topology optimisation of energy absorbers. in European Solid Mechanics Conference 2022 (2022).
• Kansara, H. et al. Data-driven modelling of scalable spinodoid structures for energy absorption. in UK Association for Computational Mechanics (UKACM) conference 2021 (2021).

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Research Projects

2021-2024, CELLCOMP: Data-driven Mechanistic Modelling of Scalable Cellular Composites for Crash Energy Absorption, EP/V049259/1, £392,388, EPSRC New Investigator Award, Principal Investigator.

2020-2023, Graphene Flagship Core3, QMUL Mini-CDT, £376,501, EU, Co-Investigator.  

2017-2018, Structural supercapacitors using hybrid carbon fibre/carbon nanotube composites, funded by University of Cambridge, CAPE Acorn Blue Sky Research Award, NMZD/256, £20K, UK, Principal Investigator.

2015-2020, Advanced Nanotube Application and Manufacturing Initiative (ANAM). funded by EPSRC, £2.8 millions, University of Cambridge, Researcher Associate.

2012-2016, Modelling the impact and crush behaviour of composite areostructures, funded by Royal Academy of Engineering and Bombardier, Queen’s University Belfast, Research Assistant (PhD)

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Research Sponsors

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