• Multi-metric Evaluation of the Effectiveness of Remote Learning in Mechanical and Industrial Engineering During the COVID-19 Pandemic: Indicators and Guidance for Future Preparedness

      Behera, Amar Kumar; de Sousa, Ricardo Alves; Oleksik, Valentin; Dong, Jingyan; Fritzen, Daniel; University of Chester; University of Aveiro; Lucian Blaga University of Sibiu; North Carolina State University; SATC College (UK Data Service, 2021-07-27)
      This data set contains data collected from 5 universities in 5 countries about the effectiveness of e-learning during the COVID-19 pandemic, specifically tailored to mechanical and industrial engineering students. A survey was administered in May, 2020 at these universities simultaneously, using Google Forms. The survey had 41 questions, including 24 questions on a 5-point Likert scale. The survey questions gathered data on their program of study, year of study, university of enrolment and mode of accessing their online learning content. The Likert scale questions on the survey gathered data on the effectiveness of digital delivery tools, student preferences for remote learning and the success of the digital delivery tools during the pandemic. All students enrolled in modules taught by the authors of this study were encouraged to fill the survey up. Additionally, remaining students in the departments associated with the authors were also encouraged to fill up the form through emails sent on mailing lists. The survey was also advertised on external websites such as survey circle and facebook. Crucial insights have been obtained after analysing this data set that link the student demographic profile (gender, program of study, year of study, university) to their preferences for remote learning and effectiveness of digital delivery tools. This data set can be used for further comparative studies and was useful to get a snapshot of student preferences and e-learning effectiveness during the COVID-19 pandemic, which required the use of e-learning tools on a wider scale than previously and using new modes such as video conferencing that were set up within a short timeframe of a few days or weeks.
    • Non-Exhaust Vehicle Emissions of Particulate Matter and VOC from Road Traffic: A Review

      Harrison, Roy; Allan, James; Caruthers, David; Heal, Matthew; Lewis, Alastair; Marner, Ben; Murrells, Tim; Williams, Andrew; University of Birmingham; University of Manchester; Cambridge Environmental Research Consultants; University of Edinburgh; University of York; Air Quality Consultants; Ricardo Energy and Environment; University of Chester; King Abdulaziz University (Elsevier, 2021-07-01)
      As exhaust emissions of particles and volatile organic compounds (VOC) from road vehicles have progressively come under greater control, non-exhaust emissions have become an increasing proportion of the total emissions, and in many countries now exceed exhaust emissions. Non-exhaust particle emissions arise from abrasion of the brakes and tyres and wear of the road surface, as well as from resuspension of road dusts. The national emissions, particle size distributions and chemical composition of each of these sources is reviewed. Most estimates of airborne concentrations derive from the use of chemical tracers of specific emissions; the tracers and airborne concentrations estimated from their use are considered. Particle size distributions have been measured both in the laboratory and in field studies, and generally show particles to be in both the coarse (PM2.5-10) and fine (PM2.5) fractions, with a larger proportion in the former. The introduction of battery electric vehicles is concluded to have only a small effect on overall road traffic particle emissions. Approaches to numerical modelling of non-exhaust particles in the atmosphere are reviewed. Abatement measures include engineering controls, especially for brake wear, improved materials (e.g. for tyre wear) and road surface cleaning and dust suppressants for resuspension. Emissions from solvents in screen wash and de-icers now dominate VOC emissions from traffic in the UK, and exhibit a very different composition to exhaust VOC emissions. Likely future trends in non-exhaust particle emissions are described.
    • The Potential of Incremental Forming Techniques for Aerospace Applications

      de Sousa, Ricardo Alves; Afonso, Daniel; Rubino, Filice; Behera, Amar Kumar; University of Aveiro; King Juan Carlos University; University of Chester
      Incremental sheet metal forming (ISF) processes are part of a set of non-classical techniques that allow producing low-batches, customized and/or specific geometries for advanced engineering applications, such as aerospace, automotive and biomedical parts. Combined or not with other joining processes and additive manufacturing techniques, ISF processes permit rapid prototyping frameworks, and can be included in the class of smart manufacturing processes. This chapter discusses the fundamentals of ISF technology, key attributes, future challenges and presents few examples related to the use of incremental forming for the development of complex parts as specifically found in aerospace applications such as aerofoils. The use of incremental forming to produce customized designs and to perform quick try-outs of ready-to-use parts contributes to decrease the time to market, decrease tooling cost and increase part design freedom.
    • Design and finite element simulation of metal-core piezoelectric fiber/epoxy matrix composites for virus detection

      Wang, Yinli; Shi, Yu; Narita, Fumio; Tohoku University; University of Chester
      Undoubtedly, the coronavirus disease 2019 (COVID-19) has received the greatest concern with a global impact, and this situation will continue for a long period of time. Looking back in history, airborne transimission diseases have caused huge casualties several times. COVID-19 as a typical airborne disease caught our attention and reminded us of the importance of preventing such diseases. Therefore, this study focuses on finding a new way to guard against the spread of these diseases such as COVID-19. This paper studies the dynamic electromechanical response of metal-core piezoelectric fiber/epoxy matrix composites, designed as mass load sensors for virus detection, by numerical modelling. The dynamic electromechanical response is simulated by applying an alternating current (AC) electric field to make the composite vibrate. Furthermore, both concentrated and distributed loads are considered to assess the sensitivity of the biosensor during modelling of the combination of both biomarker and viruses. The design parameters of this sensor, such as the resonant frequency, the position and size of the biomarker, will be studied and optimized as the key values to determine the sensitivity of detection. The novelty of this work is to propose functional composites that can detect the viruses from changes of the output voltage instead of the resonant frequency change using piezoelectric sensor and piezoelectric actuator. The contribution of this detection method will significantly shorten the detection time as it avoids fast Fourier transform (FFT) or discrete Fourier transform (DFT). The outcome of this research offers a reliable numerical model to optimize the design of the proposed biosensor for virus detection, which will contribute to the production of high-performance piezoelectric biosensors in the future.
    • Panel adjustment and error analysis for a large active main reflector antenna by using the panel adjustment matrix

      Lian, Peiyuan; Wang, Congsi; Xue, Song; Xu, Qian; Wang, Na; xiang, Binbin; Shi, Yu; Jia, Yu; Xidian University; University of Chester; Aston University; Chinese Academy of Sciences
      Active panels are generally applied in large aperture and high frequency reflector antennas, and the precise calculation of the actuator adjustment value is of great importance. First, the approximation relationship between the adjustment value and panel elastic deformation is established. Subsequently, a panel adjustment matrix for the whole reflector is derived to calculate the reflector deformation caused by the actuator adjustment. Next, the root mean square (rms) error of the deformed reflector is expressed as a quadratic form in the matrix form, and the adjustment value can be derived easily and promptly from the corresponding extreme value. The solution is expected to be unique and optimal since the aforementioned quadratic form is a convex function. Finally, a 35 m reflector antenna is adopted to perform the panel adjustments, and the effect of the adjustment errors is discussed. The results show that compared to the traditional model, where the panel elastic deformation is not considered, the proposed method exhibits a higher accuracy and is more suitable for use in large reflectors with a high operation frequency. The adjustment errors in different rings exert different influences on the gain and sidelobe level, which can help determine the actuator distribution with different precisions.
    • Computational simulation of the damage response for machining long fibre reinforced plastic (LFRP) composite parts: A review

      Wang, Xiaonan; Wang, Fuji; Gu, Tianyu; Jia, Zhenyuan; Shi, Yu; Dalian University of Technology; University of Chester
      Long fibre reinforced plastics (LFRPs) possess excellent mechanical properties and are widely used in the aerospace, transportation and energy sectors. However, their anisotropic and inhomogeneous characteristics as well as their low thermal conductivity and specific heat capacity make them prone to subsurface damage, delamination and thermal damage during the machining process, which seriously reduces the bearing capacity and shortens the service life of the components. To improve the processing quality of composites, finite element (FE) models were developed to investigate the material removal mechanism and to analyse the influence of the processing parameters on the damage. A review of current studies on composite processing modelling could significantly help researchers to understand failure initiation and development during machining and thus inspire scholars to develop new models with high prediction accuracy and computational efficiency as well as a wide range of applications. To this aim, this review paper summarises the development of LFRP machining simulations reported in the literature and the factors that can be considered in model improvement. Specifically, the existing numerical models that simulate the mechanical and thermal behaviours of LFRPs and LFRP-metal stacks in orthogonal cutting, drilling and milling are analysed. The material models used to characterise the constituent phases of the LFRP parts are reviewed. The mechanism of material removal and the damage responses during the machining of LFRP laminates under different tool geometries and processing parameters are discussed. In addition, novel and objective evaluations that concern the current simulation studies are conducted to summarise their advantages. Aspects that could be improved are further detailed, to provide suggestions for future research relating to the simulation of LFRP machining.
    • A Review of Piezoelectric and Magnetostrictive Biosensor Materials for Detection of COVID‐19 and Other Viruses

      Narita, Fumio; Wang, Zhenjin; Kurita, Hiroki; Li, Zhen; Shi, Yu; Jia, Yu; Soutis, Constantinos; Tohoku University; Nanjing University of Aeronautics and Astronautics; University of Chester; Aston University; University of Manchester
      The spread of the severe acute respiratory syndrome coronavirus has changed the lives of people around the world with a huge impact on economies and societies. The development of wearable sensors that can continuously monitor the environment for viruses may become an important research area. Here, the state of the art of research on biosensor materials for virus detection is reviewed. A general description of the principles for virus detection is included, along with a critique of the experimental work dedicated to various virus sensors, and a summary of their detection limitations. The piezoelectric sensors used for the detection of human papilloma, vaccinia, dengue, Ebola, influenza A, human immunodeficiency, and hepatitis B viruses are examined in the first section; then the second part deals with magnetostrictive sensors for the detection of bacterial spores, proteins, and classical swine fever. In addition, progress related to early detection of COVID‐19 (coronavirus disease 2019) is discussed in the final section, where remaining challenges in the field are also identified. It is believed that this review will guide material researchers in their future work of developing smart biosensors, which can further improve detection sensitivity in monitoring currently known and future virus threats.
    • Parametric Study of Environmental Conditions on The Energy Harvesting Efficiency for The Multifunctional Composite Structures

      Wen, Tao; Ratner, Alon; Jia, Yu; Shi, Yu; University of Chester;University of Warwick; Aston University
      This paper presents a parametric study of the efficacy of an integrated vibration energy harvesting device under the environmental condition representative of an offshore wind turbine. A multifunctional glass fibre composite with an integrated Micro Fibre Composite (MFC) energy harvesting device was tested by swept sine vibration under environmental conditions that ranged from – 40°C to 70°C in temperature and 10%RH to 90%RH in humidity in order to characterise the sensitivity and dependence of energy harvesting on environmental conditions. Experimental vibration testing was complemented with theoretical analysis to investigate the relative contributions to the temperature dependence of energy harvesting. This included mechanical properties of the stiffness and strength of the cantilever structure and the electrical properties of the MFC transducer, including its dielectric constants and charge coefficients. An inverse proportionality was observed between the magnitude of harvested energy and the climatic temperature. The efficiency of energy harvesting was dominated by the stiffness of the cantilever, which displayed viscoelastic temperature dependence. The sample was also tested with a vibration profile obtained from a wind turbine in order to validate the temperature influence under typical service conditions. Numerical modal analysis was used to determine the shapes of resonance modes, the frequencies of which were temperature dependent. Humidity was observed to have a secondary influence on energy harvesting, with no significant short-term effect on the structural properties of the samples within the limits of the experimental method.
    • Vibration energy harvesting of multifunctional carbon fibre composite laminate structures

      Alsaadi, Ahmed; Shi, Yu; Pan, Lei; Tao, Jie; Jia, Yu; University of Chester; Nanjing University of Aeronautics and Astronautics
      A sustainable power supply for a wide range of applications, such as powering sensors for structural health monitoring and wireless sensoring nodes for data transmission and communication used in unmanned air vehicles, automobiles, renewable energy sectors, and smart city technologies, is targeted. This paper presents an experimental and numerical study that describes an innovative technique to harvest energy resulted from environmental vibrations. A piezoelectric energy harvester was integrated onto a carbon fibre reinforced polymer (CFRP) laminate structure using the co-curing method. The integrated composite with the energy harvester was lightweight, flexible and provided robust and reliable energy outcomes, which can be used to power different low-powered wireless sensing nodes. A normalised power density of 97  μW cm−3m−2s4 was obtained from resonance frequency of 46 Hz sinusoidal waves at amplitude of 0.2 g; while the representative environmental vibration waves in various applications (aerospace, automotive, machine and bridge infrastructure) were experimentally and numerically investigated to find out the energy that can be harvested by such a multifunctional composite structure. The results showed the energy harvested at different vibration input from various industrial sectors could be sufficient to power an autonomous structural health monitoring system and wireless communications by the designed composite structure.
    • Space Phased Array Antenna Developments: A Perspective on Structural Design

      Wang, Congsi; Wang, Yan; Lian, Peiyuan; Xu, Qian; Shi, Yu; Jia, Yu; Du, Biao; Liu, Jing; Tang, Baofu; Xue, Song; et al.
      N/A
    • A Taylor-Surrogate-Model-Based Method for the Electrical Performance of Array Antennas Under Interval Position Errors

      Wang, Congsi; Yuan, Shuai; Gao, Wei; Jiang, Chao; Zhu, Cheng; Li, Peng; Wang, Zhihai; Peng, Xuelin; Shi, Yu; Xidian University; University of New South Wales; Hunan University; Nanjing Research Institute of Electronics Technology; University of Chester
      In this letter, a Taylor-surrogate-model-based method (TSMBM) is proposed to predict the bounds of power pattern of array antennas with interval position errors of antenna elements. The advantage of TSMBM is that it provides the approximate analytical solution of the problem with high precision and free of “wrapping effect.” First, the integral form of the Taylor surrogate model (IFTSM) of the distorted power pattern of array antennas is deduced. Then, the extrema point vector of IFTSM can be readily calculated within a set composed of bounds, –1 and 1. Finally, the bounds of the distorted power pattern are determined by submit- ting the extrema point vector of IFTSM to the distorted power pattern. Representative examples are presented to demonstrate the accuracy and effectiveness of the method.
    • In situ fabrication of carbon fibre–reinforced polymer composites with embedded piezoelectrics for inspection and energy harvesting applications

      Yan, Xue; Courtney, Charles; Bowen, Chris; Gathercole, Nicholas; Wen, Tao; Jia, Yu; Shi, Yu; Aerospace Research Institute of Material and Processing Technology; University of Bath; University of Chester
      Current in situ damage detection of fibre-reinforced composites typically uses sensors which are attached to the structure. This may make periodic inspection difficult for complex part geometries or in locations which are difficult to reach. To overcome these limitations, we examine the use of piezoelectric materials in the form of macro-fibre composites that are embedded into carbon fibre–reinforced polymer composites. Such a multi-material system can provide an in situ ability for damage detection, sensing or energy harvesting. In this work, the piezoelectric devices are embedded between the carbon fibre prepreg, and heat treated at elevated temperatures, enabling complete integration of the piezoelectric element into the structure. The impact of processing temperature on the properties of the macro-fibre composites are assessed, in particular with respect to the Curie temperature of the embedded ferroelectric. The mechanical properties of the carbon fibre–reinforced polymer composites are evaluated to assess the impact of the piezoelectric on tensile strength. The performance of the embedded piezoelectric devices to transmit and receive ultrasonic signals is evaluated, along with the potential to harvest power from mechanical strain for self-powered systems. Such an approach provides a route to create multi-functional materials.
    • Effect of Temperature on Electromagnetic Performance of Active Phased Array Antenna

      Wang, Yan; Wang, Congsi; Lian, Peiyuan; Xue, Sone; Liu, Jing; Gao, Wei; Shi, Yu; Wang, Zhihai; Yu, Kunpeng; Peng, Xuelin; et al.
      Active phased array antennas (APAAs) can suffer from the effects of harsh thermal environments, which are caused by the large quantity of power generated by densely packed T/R modules and external thermal impacts. The situation may be worse in the case of limited room and severe thermal loads, due to heat radiation and a low temperature sink. The temperature field of the antenna can be changed. Since large numbers of temperature-sensitive electronic components exist in T/R modules, excitation current output can be significantly affected and the electromagnetic performance of APAAs can be seriously degraded. However, due to a lack of quantitative analysis, it is difficult to directly estimate the effect of temperature on the electromagnetic performance of APAAs. Therefore, this study investigated the electromagnetic performance of APAAs as affected by two key factors—the uniformly distributed temperature field and the temperature gradient field—based on different antenna shapes and sizes, to provide theoretical guidance for their thermal design.
    • Impact Damage Characteristics of Carbon Fibre Metal Laminates: Experiments and Simulation

      Shi, Yu; Soutis, Constantinos; Pinna, Christophe; University of Chester; The University of Sheffield; The University of Manchester
      In this work, the impact response of carbon fibre metal laminates (FMLs) was experimentally and numerically studied with an improved design of the fibre composite lay-up for optimal mechanical properties and damage resistance. Two different stacking sequences (Carall 3–3/2–0.5 and Carall 5–3/2–0.5) were designed and characterised. Damage at relatively low energy impact energies (≤30 J) was investigated using Ultrasonic C-scanning and X–ray Computed Tomography (X-RCT). A 3D finite element model was developed to simulate the impact induced damage in both metal and composite layers using Abaqus/Explicit. Cohesive zone elements were introduced to capture delamination occurring between carbon fibre/epoxy plies and debonding at the interfaces between aluminium and the composite layers. Carall 5–3/2–0.5 was found to absorb more energy elastically, which indicates better resistance to damage. A good agreement is obtained between the numerically predicted results and experimental measurements in terms of force and absorbed energy during impact where the damage modes such as delamination was well simulated when compared to non-destructive techniques (NDT).
    • Effects of inkjet printed toughener on delamination suppression in drilling of carbon fibre reinforced plastics (CFRPs)

      Shi, Yu; Wang, Xiaonan; Wang, Fuji; Gu, Tianyu; Xie, Pengheng; Jia, Yu; University of Chester; Dalian University of Technology; Aston University
      Delamination has been recognised as the predominant damage induced during the drilling of carbon fibre reinforced plastics (CFRPs). It could significantly reduce the bearing capacity and shorten the service life of the designed component. To enhance the delamination resistance of CFRPs for different applications, great affords have been done to improve their interlaminar fracture toughness. However, due to the difficulty in accurately controlling the amount of the toughener applied in the interface, effect of the toughener content on the toughening efficiency is rarely studied. In this work, an experimental research was developed to investigate the performance of the toughener on the improvement of delamination resistance in the drilling of CFRPs and parametrically optimise the toughener content with the consideration of different feed rates. Specifically, poly(methyl methacrylate) (PMMA) solutions with various concentrations were selected to add on the CFRP prepreg, and co-cured together with layups. The inkjet printing technology was adopted to deposit the PMMA solutions for precisely controlled toughener contents. Through drilling experiments on the toughened CFRPs, it was found that the optimal content of the PMMA solution was 10 wt% to offer the least delamination, in particular, for the situation under the highest feed rate condition. The toughing mechanisms were also concluded by analysing the histories of the thrust force and torque in the drilling process. The results of this study is significantly contribute to the locally toughening of the composite interfaces and the improvement of the drilling quality, which is specifically helpful to strengthen the joint property for the structural design stage for the aircraft.
    • Optimisation and management of energy generated by a multifunctional MFC-integrated composite chassis for rail vehicles

      Liu, Yiding; Du, Sijun; Micallef, Christopher; Jia, Yu; Shi, Yu; Hughes, Darren; University of Warwick; University of California at Berkeley; Aston University; University of Chester
      With the advancing trend towards lighter and faster rail transport, there is an increasing interest in integrating composite and advanced multifunctional materials in order to infuse smart sensing and monitoring, energy harvesting and wireless capabilities within the otherwise purely mechanical rail structures and the infrastructure. This paper presents a holistic multiphysics numerical study, across both mechanical and electrical domains, that describes an innovative technique of harvesting energy from a piezoelectric micro fiber composites (MFC) built-in composite rail chassis structure. Representative environmental vibration data measured from a rail cabin have been critically leveraged here to help predict the actual vibratory and power output behaviour under service. Time domain mean stress distribution data from the Finite Element simulation were used to predict the raw AC voltage output of the MFCs. Conditioned power output was then calculated using circuit simulation of several state-of-the-art power conditioning circuits. A peak instantaneous rectified power of 181.9 mW was obtained when eight-stage Synchronised Switch Harvesting Capacitors (SSHC) from eight embedded MFCs were located. The results showed that the harvested energy could be sufficient to sustain a self-powered structural health monitoring system with wireless communication capabilities. This study serves as a theoretical foundation of scavenging for vibrational power from the ambient state in a rail environment as well as to pointing to design principles to develop regenerative and power neutral smart vehicles.
    • The diagnostic analysis of the fault coupling effects in planet bearing

      Xue, Song; Wang, Congsi; Howard, Ian; Lian, Peiyuan; Chen, Gaige; Wang, yan; Yan, Yuefei; Xu, Qian; Shi, Yu; Jia, Yu; et al. (Elsevier, 2019-11-09)
      The purpose of this paper is to investigate the fault coupling effects in the planet bearing as well as the corresponding vibration signatures in the resultant vibration spectrum. In a planetary gear application, the planet bearing can not only spin around the planet gear axis, but also revolve about the sun gear axis and this rotating mechanism poses a big challenge for the diagnostic analysis of the planet bearing vibration spectrum. In addition, the frequency component interaction and overlap phenomenon in the vibration spectrum caused by the fault coupling effect can even worsen the diagnosis results. To further the understanding of the fault coupling effects in a planet bearing, a 34° of freedom planetary gear model with detailed planet bearing model was established to obtain the dynamic response in the presence of various bearing fault scenarios. The method of modelling the bearing distributed faults and localized faults has been introduced in this paper, which can be further incorporated into the planetary gear model to obtain the faulted vibration signal. The “benchmark” method has been adopted to enhance the planet bearing fault impulses in the vibration signals and in total, the amplitude demodulation results from 20 planet bearing fault scenarios have been investigated and analyzed. The coherence estimation over the vibration frequency domain has been proposed as a tool to quantify the fault impact contribution from different fault modes and the results suggested that the outer raceway fault contributes most to the resultant planet bearing vibration spectrum in all the investigated fault scenarios.
    • A Compensation Method for Active Phased Array Antennas : Using a Strain-Electromagnetic Coupling Model

      Shi, Yu; Wang, Congsi; Wang, Yan; Yuan, Shuai; Duan, Baoyan; Lian, Peiyuan; Xue, Song; Du, Biao; Gao, Wei; Wang, Zhihai; et al.
      Physical deformation due to service loads seriously degrades the electromagnetic performance of active phased array antennas. However, traditional displacement-based compensation methods are moderately difficult to use because displacement measurements generally require stable references, which are hard to realize for antennas in service. For deformed antennas, strain information is directly related to their displacement, and strain sensors can overcome carrier platform constraints to measure real-time strain without affecting the antenna radiation-field distribution. We thus present a compensation method based on strain information for in-service antennas. First, the minimum number of strain sensors is determined as the main modal-order-based modal effective mass fraction. According to the modal method and analysis of spatial phase-distribution errors related to strain, a coupled strain-electromagnetic model is established to evaluate antenna performance from the measured strain. The corresponding excitation phase from the measured strain is adjusted to compensate antenna performance. Finally, the method is experimentally validated using an X-band active phased array antenna under the influence of typical deformation conditions for both boresightand scanned beams. The results demonstrate that the presented method can effectively compensate for the performance of service antennas directly from the measured strain information.
    • Effect of surface micro-pits on mode-II fracture toughness of Ti-6Al-4V/PEEK interface

      Pan, Lei; Pang, Xiaofei; Wang, Fei; Huang, Haiqiang; Shi, Yu; Tao, Jie; Nanjing University of Aeronautics and Astronautics; University of Chester (Elsevier, 2019-08-17)
      Herein, the delamination issue of TiGr(TC4/PEEK/Cf) laminate is addressed by investigating the influence of TC4(Ti-6Al-4V) surface micro-pits on mode-II interfacial fracture toughness of TC4/PEEK interface through experimental and finite element modeling. The micro-pits unit cell, unit strip and the end notched flexure (ENF) models are established based on the finite element simulations and the effect of micro-pit size parameters is studied in detail. The results of micro-pits unit cell model reveal that the presence of micro-pits can effectively buffer the interfacial stress concentration under mode-II loading conditions. Furthermore, the micro-pits unit strip model, with different micro-pit sizes, is analyzed to obtain the interface parameters, which are converted and used in the ENF model. Both the unit strip and ENF models conclude that the presence of interfacial micro-pits effectively improves the mode-II fracture toughness. It is worth mentioning that the utilization of converted interface parameters in ENF model avoided the limitation of micro-pit size and reduced the workload. Finally, the experimental and computational ENF results exhibited excellent consistency and confirmed the reliability of the proposed finite element models. The current study provides useful guidelines for the design and manufacturing of high-performance TC4/PEEK interfaces for a wide range of applications.
    • Enhancing interfacial strength between AA5083 and cryogenic adhesive via anodic oxidation and silanization

      Lei, Pan; Zhang, Aiai; Zheng, Zengmin; Duan, Lixiang; Zhang, Lei; Shi, Yu; Tao, Jie; Nanjing University of Aeronautics and Astronautics; University of Chester (Elsevier, 2018-04-27)
      AA5083 aluminum alloy was treated in turn with phosphoric-sulfuric acid anodic oxidation and then with silanization using the silane coupling agent KH560. A chemical bond (Si-O-Al) was created between the aluminum alloy and silane film, and a dehydration condensation reaction occurred between the silane film and cryogenic adhesive to enhance the bonding strength between the aluminum alloy and the cryogenic adhesive. Scanning electron microscopy, Energy dispersive spectroscopy, and Fourier transform infrared spectroscopy were used to explore the interfacial characteristics of the aluminum alloy both with and without the applied treatment. Furthermore, single lap shear tests and durability tests were performed to assess the adhesive strength of the interface between the aluminum alloy and the cryogenic adhesive at low temperature. The most improved interfacial strength using the anodic oxidation and the silanization treatments reached 33.96 MPa at −60 °C. The interface strength with the same treatments after the durability test was 25.4 MPa.