Browsing by Author "He, Feiyang"
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Item Open Access Analysis of the self-healing capability of thermoplastic elastomer capsules in a polymeric beam structure based on strain energy release behaviour during crack growth(MDPI, 2023-08-12) Almutairi, Mohammed Dukhi; He, Feiyang; Alshammari, Yousef Lafi; Alnahdi, Sultan Saleh; Khan, Muhammad AliThe objective of this study was to investigate the elastic and plastic responses of 3D-printed thermoplastic elastomer (TPE) beams under various bending loads. The study also aimed to develop a self-healing mechanism using origami TPE capsules embedded within an ABS structure. These cross-shaped capsules have the ability to be either folded or elastically deformed. When a crack occurs in the ABS structure, the strain is released, causing the TPE capsule to unfold along the crack direction, thereby enhancing the crack resistance of the ABS structure. The enhanced ability to resist cracks was confirmed through a delamination test on a double cantilever specimen subjected to quasi-static load conditions. Consistent test outcomes highlighted how the self-healing process influenced the development of structural cracks. These results indicate that the suggested self-healing mechanism has the potential to be a unique addition to current methods, which mostly rely on external healing agents.Item Open Access Effect of 3D printing process parameters on damping characteristic of cantilever beams fabricated using material extrusion(MDPI, 2023-01-04) He, Feiyang; Ning, Haoran; Khan, MuhammadThe present paper aims to investigate the process parameters and damping behaviour of the acrylonitrile butadiene styrene (ABS) cantilever beam manufactured using material extrusion (MEX). The research outcome could guide the manufacture of MEX structures to suit specific operating scenarios such as energy absorption and artificially controlled vibration responses. Our research used an experimental approach to examine the interdependencies between process parameters (nozzle size, infill density and pattern) and the damping behaviour (first-order modal damping ratio and loss factor). The impact test was carried out to obtain the damping ratio from the accelerometer. A dynamic mechanical analysis was performed for the loss factor measurement. The paper used statistical analysis to reveal significant dependencies between the process parameters and the damping behaviour. The regression models were also utilised to evaluate the mentioned statistical findings. The multiple third-order polynomials were developed to represent the relation between process parameters and modal damping ratio using stiffness as the mediation variable. The obtained results showed that the infill density affected the damping behaviour significantly. Higher infill density yielded a lower damping ratio. Nozzle size also showed a notable effect on damping. A high damping ratio was observed at a significantly low value of nozzle size. The results were confirmed using the theoretical analysis based on the underlying causes due to porosity in the MEX structure.Item Open Access The effect of printing parameters on crack growth rate of FDM ABS cantilever beam under thermo-mechanical loads(Elsevier, 2022-01-04) He, Feiyang; Alshammari, Yousef Lafi A.; Khan, MuhammadFused deposition modelling (FDM) is the most widely used additive manufacturing (AM) process in the customised and low-volume production industries. Acrylonitrile butadiene styrene (ABS) is the most commonly used thermoplastic printing material for FDM. The fabricated FDM ABS parts commonly work under thermo-mechanical loads in reality. In order to produce the high fatigue performance FDM ABS components, it is significant to investigate the effect of 3D printing parameters on crack growth. Hence, this research evaluated the crack propagation under bending fatigue test for FDM ABS beam in high-temperature conditions with varying printing parameters, including building orientations, nozzle size and layer thickness. The combination of three building orientations (0°, ±45° and 90°), three nozzle sizes (0.4, 0.6 and 0.8 mm) and three layer thickness (0.05, 0.1 and 0.15 mm) were tested under 50 to 70 °C environmental temperature ranges. The research attempted to investigate the relationship between crack growth rate and different printing parameter combinations. The study also attempted to determine the possible parameter combination which achieved the longest fatigue life for the FDM ABS specimen. Preliminary experimental results showed that the specimen with 0° building orientation, 0.8 mm filament width and 0.15 mm layer thickness vibrated for the longest time before the fracture at every different temperature.Item Open Access Effects of printing parameters on the fatigue behaviour of 3D-printed ABS under dynamic thermo-mechanical loads(MDPI, 2021-07-19) He, Feiyang; Khan, MuhammadFused deposition modelling (FDM) is the most widely used additive manufacturing process in customised and low-volume production industries due to its safe, fast, effective operation, freedom of customisation, and cost-effectiveness. Many different thermoplastic polymer materials are used in FDM. Acrylonitrile butadiene styrene (ABS) is one of the most commonly used plastics owing to its low cost, high strength and temperature resistance. The fabricated FDM ABS parts commonly work under thermo-mechanical loads in actual practice. For producing FDM ABS components that show high fatigue performance, the 3D printing parameters must be effectively optimized. Hence, this study evaluated the bending fatigue performance for FDM ABS beams under different thermo-mechanical loading conditions with varying printing parameters, including building orientations, nozzle size, and layer thickness. The combination of three building orientations (0°, ±45°, and 90°), three nozzle sizes (0.4, 0.6, and 0.8 mm) and three-layer thicknesses (0.05, 0.1, and 0.15 mm) were tested at different environmental temperatures ranging from 50 to 70 °C. The study attempted to find the optimal combination of the printing parameters to achieve the best fatigue behaviour of the FDM ABS specimen. The experiential results showed that the specimen with 0° building orientation, 0.8 mm filament width, and 0.15 mm layer thickness vibrated for the longest time before the fracture at each temperature. Both a larger nozzle size and thicker layer height can increase the fatigue life. It was concluded that printing defects significantly decreased the fatigue life of the 3D-printed ABS beam.Item Open Access An empirical torsional spring model for the inclined crack in a 3D-printed acrylonitrile butadiene styrene (ABS) cantilever beam(MDPI, 2023-01-18) Yang, Zhichao; He, Feiyang; Khan, MuhammadThis paper presents an empirical torsional spring model for the inclined crack on a 3D-printed ABS cantilever beam. The work outlined deals mainly with our previous research about an improved torsional spring model (Khan-He model), which can represent the deep vertical (90°) crack in the structure. This study used an experimental approach to investigate the relationships between the crack angle and torsional spring stiffness. ABS cantilever beams with different crack depths (1, 1.3 and 1.6 mm) and angles (30, 45, 60, 75 and 90°) were manufactured by fused deposition modelling (FDM). The impact tests were performed to obtain the dynamic response of cracked beams. The equivalent spring stiffness was calculated based on the specimen’s fundamental frequency. The results suggested that an increased crack incline angle yielded higher fundamental frequency and vibration amplitude, representing higher spring stiffness. The authors then developed an empirical spring stiffness model for inclined cracks based on the test data. These results extended the Khan-He model’s application from vertical to inclined crack prediction in FDM ABS structures.Item Open Access Evolution and new horizons in modeling crack mechanics of 3D printing polymeric structures(Elsevier, 2021-02-01) He, Feiyang; Thakur, Vijay Kumar; Khan, Muhammad A.Three-dimensionally printed parts are widely used to fabricate polymeric structures in industrial applications. The continuous use of these components in practical applications makes them prone to fracture owing to crack propagation. Extensive research articles and reviews have been published to introduce the phenomenon and significance of crack propagation behavior of polymeric structures. However, when these are reviewed with a critical eye, it has been found that a comprehensive effort is still required to compile all these previous research studies with an emphasis on thermomechanical couple loads. During the presented critical review effort, it has been found that the existing research studies and their conclusions are limited in expressing the true crack growth phenomenon for real applications. Therefore, this review concludes that the analytical and empirical study about the crack growth behavior of polymers under the time-dependent coupled loading conditions can be a novel contribution in the academic domain.Item Open Access In-situ dynamic response measurement for damage quantification of 3D printed ABS cantilever beam under thermomechanical load(MDPI, 2019-12-12) Baqasah, Hamzah; He, Feiyang; Zai, Behzad A.; Asif, Muhammad; Khan, Kamran Ahmed; Thakur, Vijay Kumar; Khan, Muhammad A.Acrylonitrile butadiene styrene (ABS) offers good mechanical properties and is effective in use to make polymeric structures for industrial applications. It is one of the most common raw material used for printing structures with fused deposition modeling (FDM). However, most of its properties and behavior are known under quasi-static loading conditions. These are suitable to design ABS structures for applications that are operated under static or dead loads. Still, comprehensive research is required to determine the properties and behavior of ABS structures under dynamic loads, especially in the presence of temperature more than the ambient. The presented research was an effort mainly to provide any evidence about the structural behavior and damage resistance of ABS material if operated under dynamic load conditions coupled with relatively high-temperature values. A non-prismatic fixed-free cantilever ABS beam was used in this study. The beam specimens were manufactured with a 3D printer based on FDM. A total of 190 specimens were tested with a combination of different temperatures, initial seeded damage or crack, and crack location values. The structural dynamic response, crack propagation, crack depth quantification, and their changes due to applied temperature were investigated by using analytical, numerical, and experimental approaches. In experiments, a combination of the modal exciter and heat mats was used to apply the dynamic loads on the beam structure with different temperature values. The response measurement and crack propagation behavior were monitored with the instrumentation, including a 200× microscope, accelerometer, and a laser vibrometer. The obtained findings could be used as an in-situ damage assessment tool to predict crack depth in an ABS beam as a function of dynamic response and applied temperature.Item Open Access Influence of printing parameters on self-cleaning properties of 3D printed polymeric fabrics(MDPI, 2022-07-31) Atwah, Ayat Adnan; Almutairi, Mohammed Dukhi; He, Feiyang; Khan, Muhammad A.The processes for making self-cleaning textile fabrics have been extensively discussed in the literature. However, the exploration of the potential for self-cleaning by controlling the fabrication parameters of the fabric at the microscopic level has not been addressed. The current evolution in 3D printing technology provides an opportunity to control parameters during fabric manufacturing and generate self-cleaning features at the woven structural level. Fabrication of 3D printed textile fabrics using the low-cost fused filament fabrication (FFF) technique has been achieved. Printing parameters such as orientation angle, layer height, and extruder width were used to control self-cleaning microscopic features in the printed fabrics. Self-cleaning features such as surface roughness, wettability contact angle, and porosity were analyzed for different values of printing parameters. The combination of three printing parameters was adjusted to provide the best self-cleaning textile fabric surface: layer height (LH) (0.15, 0.13, 0.10 mm) and extruder width (EW) (0.5, 0.4, 0.3 mm) along with two different angular printing orientations (O) (45° and 90°). Three different thermoplastic flexible filaments printing materials were used: thermoplastic polyurethane (TPU 98A), thermoplastic elastomers (TPE felaflex), and thermoplastic co-polyester (TPC flex45). Self-cleaning properties were quantified using a pre-set defined criterion. The optimization of printing parameters was modeled to achieve the best self-cleaning features for the printed specimens.Item Open Access Interdependencies between dynamic response and crack growth in a 3D-printed acrylonitrile butadiene styrene (ABS) cantilever beam under thermo-mechanical loads(MDPI, 2022-02-28) He, Feiyang; Khan, Muhammad; Aldosari, Salem MohammedAcrylonitrile butadiene styrene (ABS) is the most commonly used thermoplastic printing material for fused deposition modelling (FDM). FDM ABS can be used in a variety of complex working environments. Notably, the thermo-mechanical coupled loads under complex operating conditions may lead to cracking and ultimately catastrophic structural failure. Therefore, it is crucial to determine the crack depth and location before a structural fracture occurs. As these parameters affect the dynamic response of the structure, in this study, the fundamental frequency and displacement amplitude response of a cracked 3D-printed ABS cantilever beam in a thermal environment were analytically and experimentally investigated. The existing analytical model, specifically the torsional spring model used to calculate the fundamental frequency change to determine the crack depth and location was enhanced by the proposed Khan-He model. The analytical relationship between the displacement amplitude and crack was established in Khan-He model and validated for the first time for FDM ABS. The results show that a reduced crack depth and location farther from the fixed end correspond to a higher fundamental frequency and displacement amplitude. An elevated ambient temperature decreases the global elastic modulus of the cracked beam and results in a lower fundamental frequency. Moreover, a non-monotonic relationship exists between the displacement amplitude and ambient temperature. The displacement amplitude is more sensitive to the crack change than the fundamental frequency in the initial stages of crack growth.Item Open Access A machine learning approach to model interdependencies between dynamic response and crack propagation(MDPI, 2020-11-30) Fleet, Thomas; Kamei, Khangamlung; He, Feiyang; Khan, Muhammad A.; Khan, Kamran Ahmed; Starr, AndrewAccurate damage detection in engineering structures is a critical part of structural health monitoring. A variety of non-destructive inspection methods has been employed to detect the presence and severity of the damage. In this research, machine learning (ML) algorithms are used to assess the dynamic response of the system. It can predict the damage severity, damage location, and fundamental behaviour of the system. Fatigue damage data of aluminium and ABS under coupled mechanical loads at different temperatures are used to train the model. The model shows that natural frequency and temperature appear to be the most important predictive features for aluminium. It appears to be dominated by natural frequency and tip amplitude for ABS. The results also show that the position of the crack along the specimen appears to be of little importance for either material, allowing simultaneous prediction of location and damage severityItem Open Access Modal response of hybrid raster orientation on material extrusion printed acrylonitrile butadiene styrene and polyethylene terephthalate glycol under thermo-mechanical loads(Elsevier, 2023-02-05) Almutairi, Mohammed Dukhi; Mascarenhas, Taheer A.; Alnahdi, Sultan Saleh; He, Feiyang; Khan, Muhammad A.In this paper we look at Acrylonitrile Butadiene Styrene (ABS) and Polyethylene Terephthalate Glycol (PETG), chosen for their low cost, high strength and temperature resistance. This study evaluates the bending fatigue performance of Material extrusion (MEX) ABS and PETG cantilever beams and compares their properties while varying a printing parameter under thermal loads. The study, using custom building orientation angles of 90o, 45o and 60o between the layers, tested the beams at different temperatures from 30o to 50 °C. The results show the effects of the building orientations and the effects of temperature on the sample. The printing orientation, which is the same as loading, also slows the crack growth.Item Open Access Modelling and investigation of crack growth for 3D-printed acrylonitrile butadiene styrene (ABS) with various printing parameters and ambient temperatures(MDPI, 2021-10-29) Alshammari, Yousef Lafi A.; He, Feiyang; Khan, Muhammad A.Three-dimensional (3D) printing is one of the significant industrial manufacturing methods in the modern era. Many materials are used for 3D printing; however, as the most used material in fused deposition modelling (FDM) technology, acrylonitrile butadiene styrene (ABS) offers good mechanical properties. It is perfect for making structures for industrial applications in complex environments. Three-dimensional printing parameters, including building orientation, layers thickness, and nozzle size, critically affect the crack growth in FDM structures under complex loads. Therefore, this paper used the dynamic bending vibration test to investigate their influence on fatigue crack growth (FCG) rate under dynamic loads and the Paris power law constant C and m. The paper proposed an analytical solution to determine the stress intensity factor (SIF) at the crack tip based on the measurement of structural dynamic response. The experimental results show that the lower ambient temperature, as well as increased nozzle size and layer thickness, provide a lower FCG rate. The printing orientation, which is the same as loading, also slows the crack growth. The linear regression between these parameters and Paris Law’s coefficient also proves the same conclusion.Item Open Access A practical demonstration of autonomous ultrasonic testing for rail flaws inspection(Cranfield University, 08/11/2022) He, Feiyang; Durazo-Cardenas, Isidro; Liu, Haochen; Rahman, Miftahur; Rahimi, Masoumeh; Starr, Andrew; Poulter, MichaelThis study established the viability of autonomous ultrasonic inspections at the technology readiness level 5 (TRL 5). An autonomous ultrasonic rail inspection prototype was developed using commercially available ultrasonic instruments and an unmanned on-track vehicle platform consisting of a Clearpath's Warthog and a road-rail vehicle (RRV) trolley. The prototype was designed to travel back and forth on a segment of the test track during the test programme. Repeated fault checks were able to discover seeded artificial flaws at depths of 23 and 27 mm. The detection was indicated by an audio alarm triggered when the ultrasonic emissions exceeded the threshold of the detector gate. A plain text message sent over local area network (LAN) WIFI to a virtual server was also used to demonstrate the transmission of detection messages. The repeatability of the inspection prototype's positioning relative to the problem was confirmed using odometry, global navigation satellite system (GNSS), and positional measurements. The results of the three measurement methods were in good agreement, and the positioning inaccuracy varied between 3 and 7 cm. This study demonstrated the potential of autonomous ultrasonic checks and gave recommendations for further work and limitations.Item Open Access Tribological characterisation and modelling for the fused deposition modelling of polymeric structures under lubrication conditions(MDPI, 2023-10-17) He, Feiyang; Xu, Chenyan; Khan, MuhammadIn recent years, additive manufacturing technology, particularly in plastic component fabrication, has gained prominence. However, fundamental modelling of the influence of materials like ABS, PC, and PLA on tribological properties in fused deposition modeling (FDM) remains scarce, particularly in non-lubricated, oil-lubricated, and grease-lubricated modes. This experimental study systematically investigates the effects of material type, lubrication method, layer thickness, and infill density on FDM component tribology. A tribology analysis is conducted using a TRB3 tribometer. The results indicate a coefficient of friction (CoF) range between 0.04 and 0.2, generally increasing and decreasing with layer thickness and filler density. The lubrication impact hinges on the material surface texture. The study models the intricate relationships between these variables via full-factor analysis, showing a strong alignment between the modelled and measured friction coefficients (an average error of 3.83%). Validation tests on different materials affirm the model’s reliability and applicability.