Search

Disorders and diseases present considerable challenges to human society, and among them, dysphagia stands out as a frequently observed disorder, notably affecting both the elderly and pediatric populations. Addressing this issue has been the focus of numerous clinical and medical research efforts. However, a comprehensive approach that investigates both the mechanical and biological aspects of dysphagia holds promise for proposing and implementing more effective solutions. By exploring the mechanobiology of the human digestive system, particularly focusing on swallowing and esophageal peristalsis, a deeper understanding of dysphagia can be gained. Studying the rheological behavior of food during the digestion process becomes crucial, allowing for the customization of food diets for individuals affected by this disorder. This review provides an overview of various mathematical and finite element analysis (FEA) models that have been proposed to address dysphagia. Additionally, it explores the rheological properties of the food bolus, offering acumens that can contribute to a more nuanced understanding of the disorder. This multidimensional approach holds the potential to improve both the diagnosis and treatment of dysphagia, ultimately enhancing the quality of life for individuals affected by this condition. [ABSTRACT FROM AUTHOR]

Cutting force analysis in milling processes is essential for precision metal cutting as it contributes to understanding tool wear, optimising machining performance, and ensuring overall process stability. Numerous research papers have been published to describe modelling techniques that provide high-fidelity predictions, with recent developments highlighting the benefits of combining different methods. However, these approaches are relatively limited in their ability to predict over the wide frequency range needed to describe the tooth passing frequency (TPF) and its harmonics under varying working conditions or stages of cutter-workpiece engagement (CWE). This paper studies the prediction performance of different modelling techniques when considering wide-band noise under varying working conditions. The methods evaluated are the explicitly defined but difficult-to-parameterise Finite Element Method (FEM), Semi-Analytical Solutions (SAS), and Long Short-Term Memory (LSTM) networks, which are black-box deep learning methods incorporating time-based information. Since white-box models are still more readily adopted by industry, the paper also introduces a new post-processing model to improve the prediction accuracy of FEM and SAS based upon the Fourier Series of the TPF (FS-TPF). Over the observable range of 0 to 1500 Hz, the cutting force predictability was assessed in both the time and frequency domains using similarity of frequency distribution, Shannon entropy, and Kullback–Leibler (KL) divergence. Verification and analysis indicate that the cutting force predictability with FEM at "partial engagement" was the lowest, due to its lack of ability to describe TPF harmonics. In contrast, the LSTM model showed the best prediction performance across all tested working conditions. The new FS-TPF significantly increased FEM's prediction accuracy by approximately 50% and improved SAS's performance by 20%. Finally, a Deep Neural Network (DNN) is compared to the LSTM, suggesting that both methods are suitable for force prediction without encountering significant accuracy issues across the different stages of CWE. It was found that the key to increasing cutting force predictability to be generally applicable to all milling conditions is the capability to describe TPF harmonics across the different CWE stages in milling processes. The FS-TPF compensation can dramatically enhance the cutting force prediction accuracy of FEM and SAS, while the applied DL-LSTM and DNN models have successfully demonstrated their wide adaptability without requiring additional post-processing. [ABSTRACT FROM AUTHOR]

Highlights This study examines the influence of damage on the stiffness characteristics of synthetic fiber (Glass)‐reinforced metal laminated composite panels through static deflection analysis. The fiber‐metal laminate (FML) structural panel deflections are obtained computationally via a mathematical model using third‐order kinematics in the framework of equivalent single‐layer theory. The deflection values are obtained numerically with the help of finite element steps. The solution consistencies are verified by a convergence test and extended to perform the validation. Additionally, the numerical results are compared with the in‐house experimental data of FML bending deflection values considering the experimental properties and influence of damage. The maximum deviation in the intact deflection response was −4.27%, while the deflection response for crack damage showed a deviation of −0.57%. Again, the model is engaged in obtaining the results by varying different geometry‐dependent design parameters, including the damage data. The spherical geometry with a pre‐damaged structure demonstrates better deformation resistance under external loading. The thickness ratio (L/h) and angle layup fiber scheme show a higher deflection response. A higher‐order FE model is delved to compute the deflections of damaged FML. The model validity is verified with in‐house experimental values. The inference of parameters on the deflection values are computed numerically. The understandings of significant parameters are discussed in detail. [ABSTRACT FROM AUTHOR]

Detection of biomarkers is exploited in lab-on-a-chip devices by means of Love type Surface Acoustic Waves (SAW). Finger type arrangement of electrodes, used for InterDigital-Transducers (IDT), perform well to create and detect SAW by using electro-mechanical coupling. Efficiency of such a transceiver depends on design parameters such as chosen material orientation, thickness, placement of electrodes. An optimized design reduces production costs, hence, we need a digital twin of the device with multiphysics simulations that compute deformation and electric field. In this study, we develop a framework with the open-source package called FEniCS for modal and transient analyses of IDTs by using the Finite Element Method (FEM). Specifically, we discuss all possible sensor design parameters and propose a computational design guideline that determines the "best" thickness parameter by maximizing mass sensitivity, thus, efficiency for a Love surface acoustic wave sensor. [ABSTRACT FROM AUTHOR]

The article discusses the use of integrated FEM-Multibody Co-Simulation to analyze the structural behavior of additively manufactured hip prostheses containing cracks. The study focuses on the mechanical properties of Ti-6Al-4V alloy, commonly used in hip replacements, and the impact of additive manufacturing on the porosity and elastic behavior of the component. The research aims to correlate defect propagation to premature failures in young and athletic patients, highlighting the importance of accurate numerical analysis techniques in predicting component reliability and failure mechanisms. [Extracted from the article]

Replacing elements made of conventional plastics (like polystyrene) with biodegradable substitutes is part of the trend of sustainable development and waste reduction. The manuscript covers issues related to the design, manufacturing and testing of sports helmet protective inserts made of biodegradable material. The FEM numerical simulations carried out by the authors allowed to determine the optimal desirable mechanical properties (Re = 8.5–65 MPa, E = 500–8000 MPa for 30 × 30 mm inserts; Re = 10.5–60 MPa, E = 500–7500 MPa for 48 × 48 mm inserts; Re = 13–95 MPa, E = 400–8500 MPa for 55 × 55 mm inserts) and geometric parameters (wall thickness equal to 0.2–0.5 mm, height of 20 mm), ensuring the formation of a plastic fold, which is the most effective energy-absorbing mechanism. The conducted quasi-static compression, bending and dynamic tensile strength tests allowed to determine blends with appropriate proportions of durable PLA with more plastic PBAT, PBS and TPS that meet the established criteria: PLA50PBAT50, PLA30PBAT70 and PLA30TPS70. [ABSTRACT FROM AUTHOR]

This study investigates the problem of concavity formation on the ends of parts manufactured on CNC skew rolling mills. Numerical modeling and Taguchi method were used to determine the effects of the main parameters of skew rolling (i.e., forming angle, skew angle, reduction ratio, temperature, steel grade, dimeter ratio, velocity ratio) on the depth of concavities formed on the product ends. The simulations showed that the only parameter to have a significant impact on the concavity depth was the reduction ratio. The FEM results were then used to establish equations for calculating concavity depth and allowance for excess material with concavity. For more universality, the established equations took into account the billet diameter. The experimental validation showed high agreement between the numerical and the experimental concavity depths. [ABSTRACT FROM AUTHOR]

In this paper, for the first time, the static bending and free vibration of bi-directional functionally graded (2D-FG) nanobeams partially resting on an elastic foundation are investigated. The nanobeams are composed of four material components and exhibit mechanical characteristics that vary smoothly and continuously along the thickness and length of the beam according to a power law. For the purpose of analysis, a finite element model is established using a two-node beam element, with each node having five degrees of freedom, combining Lagrangian and Hermitian shape functions. Based on a higher-order shear deformation theory and nonlocal theory, the governing equations of the 2D-FG nanobeams are derived using Hamilton's principle. Through the comparisons of the results obtained from the model with published results in the open literature, the accuracy and reliability of the present model are confirmed. Therefore, the proposed algorithm is compatible for predicting mechanical behaviors of nanobeams with arbitrary material distribution, various boundary conditions and complex loads. New numerical results are conducted to assess the influence of parameters such as volume fraction indexes, nonlocal parameters, foundation coefficients, length-to-height ratio and boundary conditions on the bending static and free vibration behaviors of the 2D-FG nanobeams. Especially, the role of the partial elastic foundations on the bending and vibration of the 2D-FG nanobeams is extensively investigated. [ABSTRACT FROM AUTHOR]

In this work, a novel quadrilateral four-node element capable of simulating the axisymmetric-torsion deformation of small-scale solids of revolution is developed based on the consistent couple stress theory (CCST). To establish the element formulation, the C1 requirement for displacement in the CCST is enforced in weak sense by using the penalty function method and the independent nodal rotation degrees of freedom are introduced into element construction to approximate the mechanical rotation fields. Besides, the stress functions that can satisfy the relevant equilibrium equation of the axisymmetric-torsion deformation are adopted as the basic functions for designing the element’s stress trial function. Several numerical tests are carried out and the results are compared to the solutions obtained using the analytical method or hexahedral solid element from the literature. It is shown that the new element exhibits good accuracy and captures the size dependences efficiently in prediction of the axisymmetric-torsion behavior of small-scale solids. [ABSTRACT FROM AUTHOR]