Browsing by Author "Qin, Qing"

Now showing 1 - 8 of 8
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    Battery thermal management for microchannel cooling system with scanning flow method
    (IEEE, 2024-07-16) Qin, Qing; Luo, Zhenhua; Luk, Patrick
    The demand for high-performance electric vehicles has rapidly increased, necessitating rapid charging and efficient thermal battery management. High-energy-density batteries generate massive heat impacting performance, service life and safety. Thermal management plays a critical role in preserving battery integrity by regulating overall temperature and localized heat distribution, thus mitigating the risk of thermal runaway. Varies cooling technologies such as air, liquid, and multi-phase material cooling, have been utilized. However, minimizing the maximum temperature while maintaining temperature uniformity remains a critical challenge in battery thermal management. This paper introduces a novel microchannel cooling system with scanning flow for Li-ion batteries. Computational Fluid Dynamics (CFD) models are developed to investigate scanning flow cooling behavior. Parametric study examines the effects of battery numbers, valve switching frequency, and channel numbers on maximum and minimum temperatures, average temperature, and temperature differences. Furthermore, fluid analysis incorporates heat distribution and velocity behavior to study flow characteristics. Experimental analysis validates the cooling capability of the scanning flow method with a 0.17% error rate. The findings highlight scanning flow as an efficient method, enhancing temperature uniformity by 62.5% and reducing the average temperature difference by 92%. This presents a promising avenue for developing effective thermal management solutions for high-energy-density batteries.
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    Compression after impact behavior of asymmetrically tapered laminates: experimental and numerical studies
    (Elsevier, 2024-12-01) Yu, Xiaonan; Xu, Xiwu; Huang, Luofeng; Qin, Qing; Zhang, Chao
    This paper presents experimental and numerical studies on the compression after impact (CAI) behavior of composite tapered laminates. It introduces newly designed impact platforms and compression fixtures specifically tailored for the specimens. Drop-weight impacts are applied to the center of the specimens, and the resulting damage is briefly described. Compression tests are then conducted on both non-impacted and impacted specimens, with strain gauges used to monitor the strain distribution. Internal damage is detected using CT scanning and ultrasonic C-scan techniques. The numerical simulations are performed using ABAQUS/Explicit finite element analysis (FEA), incorporating an intra-laminar progressive damage model and an inter-laminar cohesive model, while additionally modeling resin pockets as elastomers. The simulation and experimental results indicate that before compression failure, impact damage in the thin section minimally affects the out-of-plane displacement, which is predominantly influenced by structural asymmetry. Stress concentration is observed at the junction between the thin and tapered sections in the compression test, while in the CAI test, stress concentration appears in the impact zone. The impact induces a notable shift in failure location and damage modes, resulting in decreased compressive strength, although the impact on stiffness remains minimal.
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    Cylindrical helical cell metamaterial with large strain zero Poisson’s ratio for shape morphing analysis
    (IOP Publishing, 2023-09-22) Qin, Qing; Dayyani, Iman
    In this paper, a novel cylindrical metamaterial with helical cell exhibiting zero Poisson's ratio (ZPR) in two different directions is introduced. Detailed Computer-aided design modelling of a curved optimised spring element is demonstrated for numerical and experimental analysis. High fidelity finite element models are developed to assess the homogenisation study of Poisson's ratios, normalised Young's modulus and torsion behaviour, demonstrating the curvature effect and independency of mechanical behaviour of cylindrical optimised spring element metamaterial from tessellation numbers. Buckling and frequency analysis of the cylindrical metamaterial with spring element are compared with equivalent shell cylinders. Moreover, experimental analysis is performed to validate the large strain ZPR and deformation mechanism demonstrated in numerical simulations. Finally, radical shape morphing analysis under different bending conditions for cylindrical metamaterial with helical cell is investigated, including deformation and actuation energy and compared with positive and negative Poisson's ratio cylinders formed by honeycomb and auxetic cells.
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    Dataset relating to "Permeability measurements for the Investigation of a practical approach to the measurement of magnetic permeability of ferrofluids"
    (Cranfield University, 2024-10-02) Lakshminarayanan, Venkatasubramanian; Qin, Qing; Geng, Jiaxin; Luo, Zhenhua
    Ferrofluids are colloids of magnetic particles in a fluid. Ferrofluids have wide range of application in engineering and medicine. Their relative magnetic permeability is one of the important parameters that needs to be measured. This dataset contains the measurements observed in the process of using an existing technique to measure magnetic permeability with a solenoid and LCR meter to identify experimental factors relevant to the accuracy of measurement.
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    Harnessing energy for wearables: a review of radio frequency energy harvesting technologies
    (MDPI, 2023-07-31) Nwalike, Ezekiel Darlington; Ibrahim, Khalifa Aliyu; Crawley, Fergus; Qin, Qing; Luk, Patrick; Luo, Zhenhua
    Wireless energy harvesting enables the conversion of ambient energy into electrical power for small wireless electronic devices. This technology offers numerous advantages, including availability, ease of implementation, wireless functionality, and cost-effectiveness. Radio frequency energy harvesting (RFEH) is a specific type of wireless energy harvesting that enables wireless power transfer by utilizing RF signals. RFEH holds immense potential for extending the lifespan of wireless sensors and wearable electronics that require low-power operation. However, despite significant advancements in RFEH technology for self-sustainable wearable devices, numerous challenges persist. This literature review focuses on three key areas: materials, antenna design, and power management, to delve into the research challenges of RFEH comprehensively. By providing an up-to-date review of research findings on RFEH, this review aims to shed light on the critical challenges, potential opportunities, and existing limitations. Moreover, it emphasizes the importance of further research and development in RFEH to advance its state-of-the-art and offer a vision for future trends in this technology.
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    Large strain zero Poisson’s ratio spring cell metamaterial with critical defect analysis and variable stiffness distributions
    (Elsevier, 2013-05-12) Qin, Qing; Dayyani, Iman
    This paper presents novel metamaterial skins formed by 3D Spring Cells exhibiting zero Poisson’s ratio in two directions with no stress concentration on joints. Precise CAD models are generated to perform numerical and experiment analysis. High-fidelity Finite element models are developed to assess the homogenisation study of zero Poisson’s ratio. Moreover, the analytical method is also used to present for normalised Young’s modulus. Parametric study for the effect of parameter on normalised Young’s modulus and Poisson’s ratio is demonstrated based on analytical method. Pure shear analysis is demonstrated to show the off-axis loading behaviour. Structural defect analysis is investigated with regarding to its deformation mechanism under tensile strain. Furthermore, variable stiffness distribution of Spring Cell metamaterials is demonstrated while maintaining large strain zero Poisson’s ratio. The frequency and buckling analysis of metamaterials formed by spring cells are investigated and compared with equivalent shell. Moreover, their mechanical behaviours including buckling and frequency are investigated. Experiment analysis is performed to validate the force–displacement, Poisson’s ratio and deformation mechanisms discussed in numerical simulations. Finally, construction material analysis is taking to investigate the relations between metamaterial Poisson’s ratio and Young’s modulus and variety types of construction material.
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    Multi-objective shape optimization of large strain 3D helical structures for mechanical metamaterials
    (Elsevier, 2022-02-18) Cimolai, Guglielmo; Dayyani, Iman; Qin, Qing
    The need for mechanical metamaterials with large strain range and lightweight properties are evidenced to engineering applications. In this regard, novel helical structures are proposed as suitable unit cell’s components of mechanical metamaterials. Three-dimensional helical structures composed of varying coil numbers, defined in a cylindrical spatial domain are shape optimized through genetic algorithm in a finite element script for conflicting objectives of minimum mass and maximum tensile range. The superior performance of the shape optimized helical structure is highlighted in terms of structural rigidity, large deformation capability, buckling and vibrational modal analysis in compare to equivalent coil springs of identical weight and comparable domain. Deformation mechanism is analyzed carefully to justify the improved performances of proposed structure. Tensile and compressive experimental analysis are undertaken to validate the enhanced strain ranges. One dimensional metamaterials implementations with various tessellation arrangements are simulated. Results show that the proposed design can effectively generate lightweight substitutes of metamaterials unit cells ligaments to improve the strain range performance. Planar and lattice metamaterial concepts employing shape optimized helical structure are illustrated to demonstrate the possibilities of promoting lightweight structural integrities in the design of mechanical metamaterials.
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    Structural mechanics of cylindrical fish-cell zero Poisson’s ratio metamaterials
    (Elsevier, 2022-03-12) Qin, Qing; Dayyani, Iman; Webb, Phil
    In this paper, a novel cylindrical metamaterial exhibiting zero Poisson’s ratio in two different directions is introduced. Detailed CAD modelling of a curved Fish-Cells necessary for numerical and experimental analysis are presented. High-fidelity finite element models are developed to assess the homogenisation studies of Poisson’s ratio, Young’s modulus and torsion behaviour, demonstrating the curvature effect and independency of the mechanical behaviour of cylindrical Fish-Cells metamaterial from tessellation numbers. Experimental analysis is performed to validate the zero Poisson’s ratio, deformation and fracture mechanism discussed in numerical simulations. Moreover, buckling and modal behaviours of the cylindrical Fish-Cells metamaterials are studied and compared with equivalent shell models.