Artículos (Ingeniería Mecánica y Fabricación)

URI permanente para esta colecciónhttps://hdl.handle.net/11441/11372

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Mostrando 1 - 20 de 300

Methodology for Three-Dimensional Analysis of Asymmetries in Joint Moments in Cycling.
(Frontiers, 2026-01-07) Martín Sosa, Ezequiel; Martín Sosa, Ezequiel; Ojeda Granja, Joaquín; Ingeniería Mecánica y Fabricación; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; TEP111: Ingeniería Mecánica
The assessment of lower-limb joint moment asymmetries during cycling is critical, as inter-limb imbalances may lead to performance decrements, overload, or injury risk. While most investigations have focused on the sagittal plane, asymmetries may also arise in the frontal and transverse planes, with potential implications for both performance and health. The present study performed a three-dimensional analysis of joint moment asymmetries and examined the influence of pedalling power on their magnitude in ten amateur cyclists under three power conditions. Asymmetries were quantified using a modified version of the Normalised Symmetry Index (NSI), the Cross-Correlation Coefficient (CCC), and the newly proposed metric Asymmetries During Cycle (ADC) index. Results indicated that these indices must be applied jointly to identify whether asymmetries arise from magnitude differences, temporal pattern discrepancies, or both. The greatest asymmetries were observed in the frontal and transverse planes, and their magnitude decreased progressively with increasing pedalling power. The novelty of this work resides in the combined application of NSI, CCC, and the ADC index to three-dimensional joint moment analysis, which together provide a comprehensive and mechanistic understanding of asymmetries throughout the pedalling cycle, an approach not previously reported in cycling biomechanics.
Dynamic modeling of a radially multilayered tether cable for a remotely-operated underwater vehicle (ROV) based on the absolute nodal coordinate formulation (ANCF)
(Elsevier, 2020-11) Zin Htun, Htun; Suzuki, Hiroyoshi; García Vallejo, Daniel; Ingeniería Mecánica y Fabricación; TEP111: Ingeniería Mecánica
This research is aimed at the accurate modeling of an ROV's tether cable with a radially multilayered circular cross-section. In the coupled motion analysis of an ROV-tether system, dynamic modeling of a numerical tether continuum, which can accurately reproduce the nonlinear motion behavior of a flexible cable, is crucial since the tether motion greatly affects the ROV's stability. To this end, a new tether cable element based on the multilayered modeling approach is developed. To deal with the inconsistency of the tether's cross-section, the integration domain on the cross-section is divided into subdomains to account for different material properties in each layer and an accurate representation of the tether's cross-section. A Kelvin-Voigt model is employed to account for the viscoelastic behavior of the inner matrix, while nearly incompressible Mooney-Rivlin model is applied for the outer sheath. Structural weakening parameters are applied to modify the beam's strain energy. A new approach for analytical determination of dissipation factors for dilatational and deviatoric responses is proposed. Through validations against the numerical studies and experiment, the effectiveness of the proposed tether cable element is verified.
Linearization approaches for general multibody systems validated through stability analysis of a benchmark bicycle model
(Springer Nature, 2021-01) García-Agúndez Blanco, Alfonso; Freire Macías, Emilio; Ingeniería Mecánica y Fabricación; Matemática Aplicada II; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; TEP111: Ingeniería Mecánica; TIC130: Investigación en Sistemas Dinámicos en Ingeniería
Linearizing the equations of motion of a constrained multibody system is a common need in, for example, stability analyses. While the theory of modelling multibody systems is well developed and many references in the literature include formalisms to generate the nonlinear equations of motion, to the best of the authors’ knowledge the linearization of those equations has not been detailed in a general procedure that could be applied to any kind of holonomic or nonholonomic multibody system. The literature includes examples of linearized equations of motion of multibody systems based on symbolic computation. Nevertheless, symbolic computation is not an option when the multibody system model is sufficiently large in terms of equations and coordinates. Efficiency of the linearization procedures has not been an issue so far since symbolic computation of the linearized equations results in very cumbersome mathematical expressions, which in some cases cannot be handled by today’s personal computers. In this paper, different numerical approaches to perform the linearization of the equations of motion of general multibody systems are developed. To validate the proposed procedures, a well-acknowledged benchmark bicycle model has been used. According to the results, the numerical linearization procedures are completely general, more efficient and very accurate.
Computational simulations of endocrine bone diseases related to pathological glandular PTH secretion using a multi-scale bone cell population model
(Frontiers Research Foundation, 2025) Modiz, Corinna; Castoldi, Natalia M.; Scheiner, Stefan; Martínez Reina, Francisco Javier; Calvo Gallego, José Luis; Sansalone, Vittorio; Martelli, Saulo; Pivonka, Peter; Ingeniería Mecánica y Fabricación; Australian Research Council
Introduction: Bone diseases significantly impact global health by compromising skeletal integrity and quality of life. In disease states linked to parathyroid hormone (PTH) glandular secretion, disrupted PTH patterns typically promote osteoclast proliferation, leading to increased bone resorption. Methods: While mathematical modeling has proven valuable in analyzing bone remodeling, current bone cell population models oversimplify PTH secretion by assuming constant levels, limiting their ability to represent disorders characterized by variations in PTH pulse characteristics. To address this, we present a novel semi-coupled approach integrating a two-state PTH receptor model with an established bone cell population model. Instead of conventional Hill-type functions, we implement a cellular activity function derived from the receptor model, incorporating pulsatile PTH patterns, cell dynamics, and intracellular communication pathways. Results: Our numerical simulations demonstrate the model’s capability to reproduce various catabolic bone diseases, providing realistic changes in bone volume fraction over a 1-year period. Notably, while direct implementation of PTH disease progression in the bone cell population model fails to capture diseases only characterized by altered pulse duration and baseline, such as glucocorticoid-induced osteoporosis, our semi-coupled approach successfully models these conditions. Discussion: This physiologically more realistic approach to endocrine disease modeling offers potential implications for optimizing therapeutic interventions and understanding disease progression mechanisms.
A new method for obtaining the stress field in plane contacts
(Elsevier, 2012-12) Vázquez Valeo, Jesús; Navarro Pintado, Carlos; Domínguez Abascal, Jaime; Ingeniería Mecánica y Fabricación
This paper presents two valuable procedures used to calculate the stress field in plane contacts between a punch and a half-plane in partial slip regime. These procedures greatly simplify both the Muskhelishvili potential and the calculation of direct stresses produced on the contact surface, and, therefore, the stress field in the half-plane is simplified as well. The results are applicable when the contacting bodies have isotropic elastic behaviour and identical mechanical properties. It is further assumed that both bodies behave as a semi-infinite medium. To validate the procedures obtained here, they are applied to two cases for which analytical solutions already exist.
On the prediction of the crack initiation path in fretting fatigue
(Elsevier, 2019-02) Bohórquez Jiménez, Luis Valentín; Vázquez Valeo, Jesús; Navarro Pintado, Carlos; Domínguez Abascal, Jaime; Ingeniería Mecánica y Fabricación
This work numerically analyses the initial crack path in a fretting fatigue situation. To this end, different criteria to estimate the crack growth (while the crack is less than 57µm) have been used. The analysis is performed using a 2D symmetric model of a cylindrical contact fretting problem, consisting of two cylindrical indenters, pressed onto a specimen, and subjected to cyclic axial loading. For the simulation, we use the finite element method (FEM), allowing for crack face contact during the corresponding parts of the fatigue cycle. Three different orientation are used to predict the new crack extension direction in each step of the crack growth simulation. To analyse the different criteria’s behaviour, a certain type of fretting fatigue test has been simulated. The experimental results from this test show an initial crack growth with an angle about 60º from the surface and a continuous rotation while growing until it reaches about 90º to the surface, being at this point the crack length longer than 49µm. The results obtained with the simulations show that the predicted crack paths vary slightly depending on the criteria used.
3D vs. 2D fatigue crack initiation and propagation in notched plates
(Elsevier, 2014-01) Navarro Pintado, Carlos; Vázquez Valeo, Jesús; Domínguez Abascal, Jaime; Ingeniería Mecánica y Fabricación; Ministerio de Ciencia e Innovación (MICIN). España
This paper analyses the influence of crack shape and the procedure used to calculate the stress distribution on the estimated fatigue life in a notched specimen. To estimate the crack shape, a series of interrupted tests at a various number of cycles was performed. Afterward, the specimens were broken to analyse crack shape. The stress intensity factor was calculated using weight functions from the stress distribution in uncracked specimens. The stresses were numerically calculated and three possibilities were analysed: plane stress, plane strain and three dimensional (3D). For each case (two dimensional (2D) or 3D geometries), an appropriate weight function was used. Each combination exhibited a different evolution of the stress intensity factor and therefore, different values of the propagation life. A life estimation model that combines the initiation and propagation phases without defining a one phase finishes and the other phase begins was applied in these tests. Finally, the lives described in the numerical analysis were compared with the experimental lives.
Fretting fatigue and shot peening: a multiaxial fatigue criterion including residual stress relaxation
(Elsevier, 2020-11) Vantadori, Sabrina; Vázquez Valeo, Jesús; Zanichelli, Andrea; Ingeniería Mecánica y Fabricación
Fretting fatigue damage is a typical material damage arising in mechanical components. In such a damage condition, surface cracks can initiate at the surface contact zone, and under a fluctuating loading they can grow up to the complete failure of the component, resulting in a catastrophic failure. In order to prevent/mitigate fretting fatigue damage, shot peening is widely used in mechanical components. The improvement due to shot peening is related to different factors, but the main one is the compressive residual stress field produced by such a treatment in a region near the contact surface. Unfortunately, both the uncertainty in measurements and stability (relaxation) of residual stress field, make shot peening effects difficult to be included in models aimed to the estimation of fatigue life. Due to this lack in the literature, especially relatively to the fretting fatigue field, in the present paper a new fretting fatigue model, that is able to consider shot peening residual stress and its relaxation, is presented. A 3D elastic-plastic finite element model, which incorporates the shot peening residual stress and its relaxations, is employed. The results obtained, in terms of stress field, are used as input data of a multiaxial stress-based criterion to estimate both fatigue lifetime and crack initiation direction.
Effect of shot peening residual stresses and surface roughness on fretting fatigue strength of Al 7075-T651
(Elsevier, 2020-02) Martín Rodríguez, Vicente; Vázquez Valeo, Jesús; Navarro Pintado, Carlos; Domínguez Abascal, Jaime; Ingeniería Mecánica y Fabricación; Junta de Andalucía
Fretting fatigue is a surface damage phenomenon appearing in mechanical contacts subjected to time variable contact forces. Typical features of fretting fatigue include: wear, oxidation, high stress concentration and non-proportional loading. The high stresses near the surface produce a rapid initiation of cracks. Among the different fretting fatigue palliatives, one of the most common is shot peening. This treatment introduces high compressive residual stresses near the surface that retard the initiation of cracks, but it also changes the microstructure and surface roughness. These residual stresses relax with the number of loading cycles. This paper experimentally studies the influence of the residual stresses and the surface condition on fretting fatigue life. To this end, in this work it is analysed the residual stress relaxation produced in fretting fatigue tests due to cycling loading. On the other hand, the effect produced by the characteristic shot peening surface roughness, is analysed by means of a series of tests in which surface's fretting test specimens are polished. In addition, experimental results obtained with fretting fatigue test specimens having a surface roughness resembling that obtained with shot peening, but without residual stress, and tests done with shot peened contact pads, are presented. In all cases, contact surfaces and fretting cracks are analysed in order to understand its fretting fatigue behaviour. Finally, a fatigue life model previously developed by the authors, but including the residual stress relaxation, is applied to the different set of tests obtaining good results. The paper concludes that shot peening greatly increases fatigue life, mainly for high-cycle fatigue. This improvement can be explained mainly through the stress distribution, with little influence of surface roughness.
Steady state cyclic behaviour of a half-plane contact in partial slip subject to varying normal load, moment, shear load, and moderate differential bulk tension
(Elsevier, 2020-01) Andresen, H.; Hills, D.A.; Barber, J.R.; Vázquez Valeo, Jesús; Ingeniería Mecánica y Fabricación; European Union (UE). H2020
A new solution for a general half-plane contact in the steady state is presented. The contacting bodies are subject to a set of constant loads – normal force, shear force and bulk tension parallel with the interface – together with an oscillatory set of the same quantities. Partial slip conditions are expected to ensue for a range of these quantities. In addition, the line of action of the normal load component does not necessarily need to pass the centre-line of the contact, thereby introducing a moment and asymmetry in the contact extent. This advancement enables a mapping to be formalised between the normal and tangential problem. An exact and easy to apply recipe is defined.
Fretting fatigue investigation on Al 7075-T651 alloy: experimental, analytical and numerical analysis
(Elsevier, 2019-07) Vázquez Valeo, Jesús; Carpinteri, Andrea; Bohórquez Jiménez, Luis Valentín; Vantadori, Sabrina; Ingeniería Mecánica y Fabricación; Ministerio Italiano de Universidades e Investigación Científica y Tecnológica
In this work, a fretting fatigue experimental campaign on Al 7075-T651 alloy specimens is simulated by using both analytical and numerical approaches. According to one of the classifications available in the literature, the theoretical approaches for fretting fatigue assessment may be divided into stress-based models or Stress-Intensity Factor (SIF) models. The analytical approach here applied falls in the group of the stress-based models, whereas two numerical methods fall in the group of the SIF-based models. The fatigue assessment is performed by evaluating both crack path and lifetime.
Frictional half-plane contact problems subject to alternating normal and shear loads and tension in the steady state
(Elsevier, 2019) Andresen, H.; Hills, D.A.; Barber, J.R.; Vázquez Valeo, Jesús; Ingeniería Mecánica y Fabricación; European Union (UE). H2020
The problem of a general, symmetric contact, between elastically similar bodies, and capable of idealisation using half-plane theory, is studied in the presence of interfacial friction. It is subject to a constant set of loads - normal force, shear force and bulk tension parallel with the interface - together with an oscillatory set of the same quantities, and is in the steady state. Partial slip conditions are expected to ensue for a range of these quantities, and the permanent stick zone is explicitly established, thereby effectively specifying the maximum extent of the slip zones. Exact and approximate, easy to apply recipes are obtained.
Analysis of fretting fatigue initial crack path in A17075-T651 using cylindrical contact
(Elsevier, 2017-04) Vázquez Valeo, Jesús; Navarro Pintado, Carlos; Domínguez Abascal, Jaime; Ingeniería Mecánica y Fabricación
This paper analyses the initial crack path in a fretting fatigue test of Al7075-T651 alloy with a cylindrical contact and compares the capability of some multiaxial fatigue criteria to predict the crack initiation path. The experimental crack initiation paths obtained in the tests are optically measured along the fracture surface using a focus variation technique. The Fatemi-Socie (FS) and Smith-Watson-Topper (SWT) multiaxial fatigue parameters obtained from an analytical model, allow us to determine the controlling parameters of the crack initiation process observed in the tests and to estimate the crack path during the early stage of the crack growth.
A model to predict fretting fatigue life including residual stresses
(Elsevier, 2014-10) Vázquez Valeo, Jesús; Navarro Pintado, Carlos; Domínguez Abascal, Jaime; Ingeniería Mecánica y Fabricación
This paper proposes a multiaxial fatigue life model that considers the presence and cyclic relaxation of a residual stress field. Although the model has been developed for fretting fatigue under spherical contact conditions, and considers a residual stress field induced by specific laser and shot-peening treatments, its general structure can be applied to other fatigue configurations in which a residual stress field is present. The model predicts the total fatigue life as a combination of the life spent during the initiation phase and the life associated with the propagation phase. The transition length is not previously fixed but depends on the particular loading conditions, geometry and material properties of the analysed problem. The residual stress field was measured and introduced in the model as cycle dependent stresses, and thus, two types of relaxations were introduced in the model: plastic and cyclic. All fatigue life estimations are compared to the experimental results to understand the effect of stress relaxation on fretting fatigue life.
Analysis of the effect of a textured surface on fretting fatigue
(Elsevier, 2013-07) Vázquez Valeo, Jesús; Navarro Pintado, Carlos; Domínguez Abascal, Jaime; Ingeniería Mecánica y Fabricación
This paper analyses the effect of a wavy regular surface texturing on fretting fatigue life, and more specifically, studies the influence of this regular pattern on the initiation and crack propagation phases in fretting fatigue. In this work, an elastic—plastic finite element model (FEM) is used to simulate the contact between a half-plane and a cylindrical punch. In the simulations, three types of geometrical configurations are studied: one in which all of the contacting surfaces are smooth, a second with contact between a smooth half-plane and a cylindrical pad with a wavy surface, and the third that simulates contact between a half-plane with a wavy surface and a smooth cylindrical pad.
Anisotropic and hyperelastic mechanical response of 3D printed TPU parts
(Springer Nature, 2025-08) Martín Sosa, Ezequiel; Távara Mendoza, Luis Arístides; Ojeda Granja, Joaquín; Estefani Morales, Alejandro; Ingeniería Mecánica y Fabricación; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; TEP111: Ingeniería Mecánica
Thermoplastic polyurethane (TPU) is usually considered isotropic and hyperelastic. Nevertheless, when 3D printing techniques as fused deposition modelling (FDM) are used, an anisotropic behaviour (inherent to the process) is expected. The aim of the present research is to analyse the isolated effect of the raster angle on the mechanical response of 3D printed TPU parts. To avoid other effects, several specimens were manufactured with 100% infill density and parallel straight lines infill pattern. Four different printing configurations were analysed, 0, ±45, 90 and concentric pattern. The specimens were subjected to tensile loading and obtained data was used as input to fit three hyperelastic behaviour models, specifically the neo-Hookean, Ogden and Mooney–Rivlin models are compared. The obtained results show that the raster angles have a clear effect on the mechanical properties of the 3D printed parts, leading to an anisotropic behaviour of the obtained specimens and on the appearance of the different stages of the hyperelastic behaviour. In addition, the fitting models used allowed to conclude that the neo-Hookean model is the best fitting the initial linear-elastic zone, while for the whole stress–strain curve, both the Ogden and Mooney–Rivlin models produce very good approximations.
Kinematic Analysis of Patients with Charcot–Marie–Tooth Disease Using OpenSim
(MDPI, 2025-09-16) Martín Sosa, Ezequiel; Mayo Núñez, Juana María; Ferrand Ferri, Patricia; Zarco Periñán, María José; Romero Sánchez, Francisco; Ojeda Granja, Joaquín; Ingeniería Mecánica y Fabricación; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; TEP111: Ingeniería Mecánica
This study proposes a methodology for conducting computational simulations of pathological gait. The literature shows a consensus that biomechanical models for gait analysis should be formulated as control problems. To achieve this, it is common practice to guide the solution using kinematic or kinetic data to prevent temporal instability. The aim of this study is to implement a biomechanical model of the Charcot–Marie–Tooth disease in OpenSim software that enables more comprehensive simulations, which may in future involve the musculoskeletal system of patient and predictive studies. In this way, it will be possible to design specific active assistive devices tailored to each patient. Experimental gait data from six Charcot–Marie–Tooth patients were used. The dataset comprises threedimensional trajectories of reflective markers placed according to the Davis-Heel protocol. The acquired data allowed a patient-specific adjustment of the biomechanical model. The inverse kinematic was solved, and the results were validated by comparing them with those obtained using the commercial BTS Bioengineering® software. The results show a strong alignment in ankle kinematics between the OpenSim model and the data generated by BTS Bioengineering®. Additionally, the kinematic results have been compared with normative curves, allowing the identification of potential areas for intervention using active assistive devices aimed at improving movement patterns of patients.
Closed-form solutions for tilted three-part piecewise-quadratic half-plane contacts
(Elsevier, 2019-01) Andresen, H.; Hills, D.A.; Vázquez Valeo, Jesús; Ingeniería Mecánica y Fabricación; European Union (UE). H2020
A general half-plane contact problem in which the geometry is specified in a piecewise-quadratic sense over three segments is solved in closed form. This includes the effects of a moment applied sufficient to introduce separation of one segment and the application of a shearing force sufficient or insufficient to cause sliding. Extending existing solutions to asymmetrical problems is necessary in order to broaden our understanding of the behaviour of dovetail roots of gas turbine fan blades. In previous studies symmetrical contacts have often been used to represent a dovetail flank contact. In the asymmetrical case, the contact pressure may be considerably higher at one of the contact edges compared to the corresponding symmetrical case. Exploiting the generality provided with the solution presented in this study, several simpler indenter problems are investigated making use of an algebraic manipulator. The Mathematica code is made available for download.
Explicit equations for sub-surface stress field in plane contacts
(Elsevier, 2013-02) Vázquez Valeo, Jesús; Navarro Pintado, Carlos; Domínguez Abascal, Jaime; Ingeniería Mecánica y Fabricación
This paper presents a new method to directly and explicitly calculate all of the components of the sub-surface stress field in plane contacts once the surface contact stress distributions are known. The method is applicable when the contacting bodies have isotropic elastic behaviour, identical mechanical properties and can be modelled as elastic half-planes. Although the method presented here has direct application in the case of plane contacts, it is also applicable in other mechanical problems that lead to a stress distribution at the surface. The procedure described here is applied to find the interior stress field generated by the well-known Carter's solution for a rolling contact.
Nucleation and early crack path in fretting fatigue
(Elsevier, 2017-07) Navarro Pintado, Carlos; Vázquez Valeo, Jesús; Domínguez Abascal, Jaime; Ingeniería Mecánica y Fabricación; Ministerio de Economía y Competitividad (MINECO). España
The initial crack path is analysed in a series of fretting fatigue tests with cylindrical contact. In such tests, both specimens and pads are made of Al7075-T651 alloy and a non-proportional multiaxial stress state with a significant stress gradient is present. The crack initiation path along the fracture surface is optically measured using a focus variation technique. The contact stress/strain fields analytically obtained, in conjunction with either the Fatemi-Socie (FS) or Smith-Watson-Topper (SWT) multiaxial fatigue parameters, allow us to determine the controlling parameters of the crack initiation process observed in the tests, and to estimate the crack path during the early stage of the crack growth. These estimations are compared with the experimental results. Finally, a fracture mechanics approach is also employed where the crack paths measured are compared with the stress intensity factor (SIF) of cracks with different lengths and orientations showing also good results.

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