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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/3
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Publication Metadata only Design and manufacturing of a hip joint motion simulator with a novel modular design approach(Springer Heidelberg, 2023) Mihcin, Senay; Department of Mechanical Engineering; Torabnia, Shams; Lazoğlu, İsmail; Department of Mechanical Engineering; Manufacturing and Automation Research Center (MARC); Graduate School of Sciences and Engineering; College of EngineeringThe study is aimed to develop a hip joint wear simulator using a modular design approach to help experimentally monitor and control critical wear parameters to validate in-silico wear models. The proper control and application of wear parameters such as the range of motion, and the applied force values while estimating the lost material due to wear are essential for thorough analysis of wear phenomena for artificial joints. The simulator's dynamics were first modeled, then dynamic loading data was used to calculate the forces, which were further used for topology optimization to reduce the forces acting on each joint. The reduction of the link weights, connected to the actuators, intends to improve the quality of motion transferred to the femoral head. The modular design approach enables topology-optimized geometry, associated gravitational and dynamic forces, resulting in a cost-effective, energy-efficient product. Moreover, this design allows integration of the subject specific data by allowing different boundary conditions following the requirements of industry 5.0. Overall, the in-vitro motion stimulations of the hip-joint prosthesis and the modular design approach used in the study might help improve the accuracy and the effectiveness of wear simulations, which could lead into the development of better and longer-lasting joint prostheses for all. The subject-specific and society-based daily life data implemented as boundary conditions enable inclusion of the personalized effects. Next, with the results of the simulator, CEN Workshop Agreement (CWA) application is intended to cover the personalized effects for previously excluded populations, providing solution to inclusive design for all.Publication Metadata only Effect of finger moisture on tactile perception of electroadhesion(Institute of Electrical and Electronics Engineers, 2024) Lefevre, Philippe; Martinsen, Orjan Grottem; Department of Mechanical Engineering; Aliabbasi, Easa; Muzammil, Muhammad; Şirin, Ömer; Başdoğan, Çağatay; Department of Mechanical Engineering; Graduate School of Sciences and Engineering; College of EngineeringWe investigate the effect of finger moisture on the tactile perception of electroadhesion with 10 participants. Participants with moist fingers exhibited markedly higher threshold levels. Our electrical impedance measurements show a substantial reduction in impedance magnitude when sweat is present at the finger-touchscreen interface, indicating increased conductivity. Supporting this, our mechanical friction measurements show that the relative increase in electrostatic force due to electroadhesion is lower for a moist finger.Publication Metadata only Ice growth detection and the de-icing using dual functional capacitive sensor(ELSEVIER SCI LTD, 2024) Department of Mechanical Engineering; Malik, Anjum Naeem; Lazoğlu, İsmail; Department of Mechanical Engineering; Manufacturing and Automation Research Center (MARC); Graduate School of Sciences and Engineering; College of EngineeringIce detectors are vital for ice mitigation systems, ensuring accurate ice growth measurements across multiple icing-de-icing cycles. Residue ice on the sensor can lead to erroneous readings in subsequent cycles, so its removal is critical to obtain accurate readings. This article presents a novel capacitive ice detector with selfdeicing functionality employing nichrome electrodes for both sensing and de-icing. The sensor underwent testing in a cooling chamber for validation. The results confirm the developed ice detector's ability to quantify ice within 1 to 4 mm with up to 7.5 % error, while the de-icing unit consumes 35 W to remove a 2 mm ice layer in 60 s. Capacitive sensor de-icing can significantly enhance the performance of ice mitigation systems. This research significantly advances ice detection technology by providing a reliable method for accurate ice measurement and removal, offering a valuable foundation for future improvements in the field of ice mitigation systems.Publication Metadata only Experimental admittance-based system identification for equivalent circuit modeling of piezoelectric energy harvesters on a plate(Academic Press, 2024) Aghakhani, Amirreza; Department of Mechanical Engineering; Hoseyni, Seyedmorteza; Başdoğan, İpek; Department of Mechanical Engineering; Graduate School of Sciences and Engineering; College of EngineeringEquivalent circuit modeling is a useful tool for piezoelectric energy harvesters to analyze the electromechanical response of the system especially when complex host structure geometries and nonlinear circuits are used in the harvesting systems. Previous studies have used analytical and finite element models to estimate the equivalent circuit model (ECM) of piezoelectric energy harvesters (PEH) on beam- and plate-like structures. However, those methods require accurate analytical and/or numerical representation of the PEH. Here, we present an experimental admittance-based system identification method that allows us to identify the multi-modal ECM without prior knowledge of the host plate's geometry and/or physical properties of the piezoelectric patches. Using the proposed experimental method, we obtain the electromechanical frequency–response admittance of the PEH system at each vibration mode, and thereby, we calculate the equivalent system parameters. Additionally, a novel experimental technique is presented for the identification of the equivalent voltage sources associated with each LCR branch of the ECM. The derived ECM is experimentally validated for single and multiple piezoelectric patch harvesters on a plate. The electrical frequency response of the system has been validated for standard AC and rectifier circuits using SPICE software. Overall, the proposed admittance-based system identification is an accurate and robust method to identify the equivalent system parameters, making it a practical and reliable tool for modeling piezoelectric energy harvesting systems.Publication Metadata only Numerical simulation of milling operations on flexible composite parts(MATERIALS RESEARCH FORUM LLC, 2024) Nutte, Matthias; Riviere-Lorphevre, Edouard; Dambly, Valentin; Arrazola, Pedro-Jose; Ducobu, Francois; Department of Mechanical Engineering; Lazoğlu, İsmail; Department of Mechanical Engineering; Manufacturing and Automation Research Center (MARC); College of EngineeringFiber-reinforced polymers (FRPs) are a widely used and growing material in industry, thanks to their excellent mechanical properties. Manufactured FRPs parts usually have thin walls. These parts also require finishing operations such as edge trimming. Problems like those encountered when machining thin metal parts are also encountered with FRPs: form error, chatter vibrations and poor surface finish. However, the study and numerical modelling of thin FRP parts are not well developed up to now. The aim of this paper is to demonstrate the feasibility of adapting a numerical model for metals to FRPs. The modelling of the shape error during the thinning of a CFRP (Carbon Fiber Reinforced Polymers) part is studied in this paper using a quasi-static analysis. Compared to metals, two adaptations are introduced here for the FRPs. First, the material properties are adapted from isotropic to orthotropic. Secondly, a mechanical model was applied to calculate cutting forces for FRPs. The results of the study show the feasibility of this adaptation and examination of form error in the case of FRPs.Publication Metadata only Tool wear prediction through ai-assisted digital shadow using industrial edge device(Elsevier Sci Ltd, 2024) Kecibas, Gamze; Uresin, Ugur; Irican, Mumin; Department of Mechanical Engineering; Chehrehzad, Mohammadreza; Beşirova, Cemile; Lazoğlu, İsmail; Department of Mechanical Engineering; Manufacturing and Automation Research Center (MARC); Graduate School of Sciences and Engineering; College of EngineeringFlank wear of drilling tools in manufacturing is among the main factors affecting product quality and productivity. In this study, an AI-assisted digital shadow was created for the instant prediction of the drilling flank tool wear. The drilling data were collected simultaneously using an industrial edge device and a rotary dynamometer. Feature engineering was conducted on the collected data from devices in time and frequency domains. A recurrent neural network (RNN) based on bidirectional long short-term memory (Bi-LSTM) and bidirectional gated recurrent unit (Bi-GRU) architectures was implemented on specified tool wear regions dataset. The digital shadow was created using the industrial edge device and the predictive AI model to minimize costs by reducing the need for expensive multi-sensors, manufacturing downtime, and tool underuse or overuse in a smart manufacturing system. The proposed model predicts with high accuracy and computational time efficiency and can be integrated into digital twin systems.Publication Metadata only Development of a lunar vehicle with a hybrid rocket engine produced using lunar resources(Springer, 2024) Yalcintas, Ali; Department of Mechanical Engineering; Yelken, Ümit; Karabeyoğlu, Mustafa Arif; Department of Mechanical Engineering; Graduate School of Sciences and Engineering; College of EngineeringThis article presents a comprehensive study on the innovative use of in-situ lunar resources for the development of a hybrid rocket engine utilizing magnesium (Mg) and aluminium (Al), which are abundantly available in lunar regolith. The primary focus is on the feasibility and sustainability of using these metal oxides as primary fuels in propulsion systems specifically designed for lunar missions. The research encompasses the design phases of a lunar lander, highlighting the application of these metals in the engine design to facilitate efficient space travel between research stations on the Moon's surface. Detailed discussions cover the extraction and processing of Mg and Al directly on the lunar surface through adapted electrolysis processes suitable for the Moon's environment. The article also explores the engineering of a cryogenic tank system using native lunar materials to address the challenges posed by the Moon's extreme temperature fluctuations. A key component of the study is the simulation of simple trajectory calculations for travel between lunar research locations using the newly designed hybrid rocket engine. Theoretical analyses suggest that this metal-based propulsion technology could significantly enhance the logistical capabilities of lunar exploration missions, offering a viable solution for both crewed and uncrewed missions. The development of such technologies not only aims to reduce Earth dependence by utilizing lunar resources but also sets a precedent for future interplanetary travel infrastructure.Publication Metadata only A novel approach to tube design via von Mises probability distribution(Taylor and Francis Ltd., 2024) Subay, Şehmuz Ali; Department of Mechanical Engineering; Oral, Atacan; Subaşı, Ömer; Öztürk, Çağlar; Lazoğlu, İsmail; Department of Mechanical Engineering; Manufacturing and Automation Research Center (MARC); Graduate School of Sciences and Engineering; College of EngineeringDischarge tube is a critical component in a reciprocating compressor that carries the refrigerant. It also transmits vibrations from compressor body to housing, making the design of tube a complex engineering problem combining static, modal and flow behaviour. This study proposes a novel design algorithm for discharge tube, to decrease the dependency on the trial-and-error approach commonly used by manufacturers. The computational approach creates a tube that connects the inlet and outlet using von Mises probability distribution. The created geometries are checked for static and dynamic properties using FEA. The algorithm continues until a candidate design passes the imposed thresholds. The candidate designs perform similarly to benchmark in evaluated aspects, demonstrating promising results. The presented algorithm is successful in generating alternative tube designs from scratch and can accommodate varying requirements. The main novelty of this study is the development of a comprehensive decision algorithm that considers multiple engineering parameters simultaneously. © 2022 Informa UK Limited, trading as Taylor & Francis Group.Publication Metadata only Switching the left and the right hearts: a novel BI-ventricle mechanical support strategy with spared native single-ventricle(Springer, 2023) Şişli, Emrah; Aka, İbrahim Başar; Tuncer, Osman Nuri; Atay, Yüksel; Özbaran, Mustafa; Department of Mechanical Engineering; Yıldırım, Canberk; Pekkan, Kerem; Department of Mechanical Engineering; Graduate School of Sciences and Engineering; College of EngineeringEnd-stage Fontan patients with single-ventricle (SV) circulation are often bridged-to-heart transplantation via mechanical circulatory support (MCS). Donor shortage and complexity of the SV physiology demand innovative MCS. In this paper, an out-of-the-box circulation concept, in which the left and right ventricles are switched with each other is introduced as a novel bi-ventricle MCS configuration for the "failing" Fontan patients. In the proposed configuration, the systemic circulation is maintained through a conventional mechanical ventricle assist device (VAD) while the venous circulation is delegated to the native SV. This approach spares the SV and puts it to a new use at the right-side providing the most-needed venous flow pulsatility to the failed Fontan circulation. To analyze its feasibility and performance, eight SV failure modes have been studied via an established multi-compartmental lumped parameter cardiovascular model (LPM). Here the LPM model is experimentally validated against the corresponding pulsatile mock-up flow loop measurements of a representative 15-year-old Fontan patient employing a clinically-approved VAD (Medtronic-HeartWare). The proposed surgical configuration maintained the healthy cardiac index (3-3.5 l/min/m(2)) and the normal mean systemic arterial pressure levels. For a failed SV with low ejection fraction (EF = 26%), representing a typical systemic Fontan failure, the proposed configuration enabled a similar to 28 mmHg amplitude in the venous/pulmonary waveforms and a 2 mmHg decrease in the central venous pressure (CVP) together with acceptable mean pulmonary artery pressures (17.5 mmHg). The pulmonary vascular resistance (PVR)-SV failure case provided a similar to 5 mmHg drop in the CVP, with venous/pulmonary pulsatility reaching to similar to 22 mmHg. For the high PVR failure case with a healthy SV (EF = 44%) pulmonary hypertension is likely to occur as expected. While this condition is routinely encountered during the heart transplantation and managed through pulmonary vasodilators a need for precise functional assessment of the spared failed-ventricle is recommended if utilized in the PVR failure mode. Comprehensive in vitro and in silico results encourage this novel concept as a low-cost, more physiological alternative to the conventional bi-ventricle MCS pending animal experiments.Publication Metadata only Myocardial biomechanics and the consequent differentially expressed genes of the left atrial ligation chick embryonic model of hypoplastic left heart syndrome(Springer, 2023) Chan, Wei Xuan; Motakis, Efthymios; Ho, Sheldon; Yap, Choon Hwai; Lashkarinia, S. Samaneh; Department of Mechanical Engineering; Siddiqui, Hummaira Banu; Çoban, Mervenur; Sevgin, Börteçine; Pekkan, Kerem; Department of Mechanical Engineering; College of Engineering; Graduate School of Sciences and EngineeringLeft atrial ligation (LAL) of the chick embryonic heart is a model of the hypoplastic left heart syndrome (HLHS) where a purely mechanical intervention without genetic or pharmacological manipulation is employed to initiate cardiac malformation. It is thus a key model for understanding the biomechanical origins of HLHS. However, its myocardial mechanics and subsequent gene expressions are not well-understood. We performed finite element (FE) modeling and single-cell RNA sequencing to address this. 4D high-frequency ultrasound imaging of chick embryonic hearts at HH25 (ED 4.5) were obtained for both LAL and control. Motion tracking was performed to quantify strains. Image-based FE modeling was conducted, using the direction of the smallest strain eigenvector as the orientations of contractions, the Guccione active tension model and a Fung-type transversely isotropic passive stiffness model that was determined via micro-pipette aspiration. Single-cell RNA sequencing of left ventricle (LV) heart tissues was performed for normal and LAL embryos at HH30 (ED 6.5) and differentially expressed genes (DEG) were identified.After LAL, LV thickness increased by 33%, strains in the myofiber direction increased by 42%, while stresses in the myofiber direction decreased by 50%. These were likely related to the reduction in ventricular preload and underloading of the LV due to LAL. RNA-seq data revealed potentially related DEG in myocytes, including mechano-sensing genes (Cadherins, NOTCH1, etc.), myosin contractility genes (MLCK, MLCP, etc.), calcium signaling genes (PI3K, PMCA, etc.), and genes related to fibrosis and fibroelastosis (TGF-beta, BMP, etc.). We elucidated the changes to the myocardial biomechanics brought by LAL and the corresponding changes to myocyte gene expressions. These data may be useful in identifying the mechanobiological pathways of HLHS.