Grupos Investigadores

Miembros del Grupo

Sánchez Apezetxea
Oyarzabal Albas

Líneas de Investigación

  • Asistencia a la conducción & vehículo autónomo
  • Caracterización estática y dinámica y modelización de elementos de suspensión y/o unión
  • Empleo de _Smart materials_ en elementos de suspensión y fabricación de dichos elementos
  • Estudio de fenómenos de fatiga y envejecimiento en piezas de suspensión. Modelos de fallo
  • Modelado multibody de vehículo y simulaciones dinámicas, tanto en automoción como en ferrocarril
  • Transmisión de ruido y vibraciones. Sistemas de amortiguamiento

Palabras Clave

  • Dinámica de vehículos
  • Elementos de suspensión
  • Modelos avanzados de componentes
  • Modelos FEM
  • Smart materials
  • Vehículo autónomo
  • Vibraciones y su amortiguamiento

Publicaciones Científicas desde 2018

  • Autores: Erenchun Etxeburua, Aitor; Kari, L.; Blanco Mula, Blas; et al.
    ISSN: 1045-389X Vol.35 N° 1 2023 págs. 29 - 48
    The attenuation of the structure-borne sound caused by elevator systems in residential buildings is a priority for manufacturers. This work develops a model of an active control isolation system for the vibrations produced by the elevator drive machine. This solution proposes the substitution of conventional passive isolators by new ones made of a magnetorheological elastomer (MRE), a smart material whose modulus can be modified by applying a magnetic field. To guide the design process, MRE isolators are fabricated and experimentally tested statically and dynamically in compression mode. Subsequently, the parameters of the MRE are fitted to build a nonlinear material sub-model that accounts for the frequency, amplitude, and magnetic field dependency. Afterward, a global model of the elevator drive machine vibration isolation system is developed, which incorporates the drive machine, structure, and MRE-based isolator. To enhance vibration isolation, two active control strategies are designed and assessed. Simulation results predict that active control systems based on MRE isolators improve vibration isolation as compared to traditional passive systems. The excitation amplitude and frequency, along with the control strategy and magnetization of the MRE isolators are shown to be critical parameters when designing an active control solution.
  • Autores: Mendía-García, I. (Autor de correspondencia); Facchinetti, A.; Bruni, S.; et al.
    ISSN: 0022-460X Vol.557 2023 págs. 117740
    The present research addresses the dynamic behaviour of an air spring with a pipeline connected to a reservoir in a frequency range up to 400 Hz, in which structure-borne vibration transmission may occur due to both the structural behaviour of the bellows and fluid dynamics in the pneumatic circuit of the suspension. Based on experimental results, three frequency ranges are distinguished where different resonances of the suspension appear: low (up to 30 Hz) due to the air flow between the bellows and the surge reservoir, intermediate (30-150 Hz) due to the formation of standing waves in the pipeline and high (beyond 150 Hz) due to the structural dynamics of the bellows. A novel modelling technique to predict the dynamic behaviour of the pneumatic system in all these frequency ranges is presented and validated: this consists of an enhanced Finite Element Model (FEM) considering the structural properties of the bellows and the effect of pressurised air in the bellows and in the reservoir, coupled to a model of fluid exchange between the two main air volumes which is defined using a VUFLUIDECH user subroutine developed in ABAQUS. The study focusses on the axial dynamic stiffness of the pneumatic suspension, which plays a key role in determining the transmissibility of the suspension. However, the mathematical model introduced in the paper is capable of predicting also the vibration modes of the suspension in shear and rotation, which may be relevant in some applications, e.g. when air springs are used in vehicle suspensions.
  • Autores: Rodríguez De Arana, Borja (Autor de correspondencia); Ciáurriz Mañú, Pablo; Gil-Negrete Laborda, Nere; et al.
    Revista: SENSORS
    ISSN: 1424-8220 Vol.23 N° 18 2023
    The condition monitoring of an overhead contact line (OCL) is investigated by developing an innovative monitoring system for a pantograph on an electrical multiple unit of a regional line. Kinematic and dynamic modelling of the pantograph is conducted to support the designed monitoring system. The modelling is proved through rigorous test-rig experiments, while the proposed methodology is then validated through extensive field tests. The field tests serve a dual purpose: First, to validate the monitoring system using benchmark measurements of the tCat (R) trolley, and second, to assess the reproducibility of measurements in a realistic case. This paper presents the OCL monitoring system developed in the framework of the H2020 project SIA. The accuracy of our results is not far from that of other commercial systems, with just 12 mm of absolute error in the height measurement. Therefore, they provide reliable information about trends in various key performance indicators (KPIs) that facilitates the early detection of failures and the diagnosis of anomalies. The results highlight the importance of model calibration and validation in enabling novel health monitoring capabilities for the pantograph. By continuously monitoring the parameters and tracking their degradation trends, our approach allows for optimized scheduling of maintenance tasks for the OCL.
  • Autores: Mendia-Garcia, I. (Autor de correspondencia); Gil-Negrete Laborda, Nere; Pradera Mallabiabarrena, Ainara; et al.
    ISSN: 0042-3114 Vol.60 N° 3 2022 págs. 835 - 864
    The air spring is the main part of the secondary suspension of passenger railway vehicles. The aim of this paper is to review existing modelling techniques for air springs in order to check if challenges set in the past decade for available models have been met. The advantages and disadvantages of different air spring models (phenomenological/mechanical, thermodynamic, analytic, FEM) are summarised and discussed from the point of view of: model accuracy, multiphysics interaction, influence of structural and material non-linearities, obtention of parameters, frequency range and the balance between accuracy and computational effort. The first conclusion is that current research is mainly focused on the vertical behaviour with less attention paid to the lateral performance. Moreover, it is concluded that further research is needed to include non-linearities of the bellow and to consider fluid-structural interaction; this would allow improving the model of vertical behaviour and evaluating better the lateral performance of the pneumatic system. FEM models might be an interesting tool that allows performing a more complete analysis of air springs (combining different physics, including material non-linearities, considering the real shape of the bellow and reinforcing fibres, etc) favouring the comfort analysis and including the lateral dynamics of the air spring.
  • Autores: Erenchun, A. (Autor de correspondencia); Blanco Mula, Blas; Gil-Negrete Laborda, Nere; et al.
    ISSN: 0142-9418 Vol.111 2022 págs. 107617
    The effect of the lubrication on the mechanical behavior of magnetorheological elastomers (MREs) in compression mode is experimentally studied. According to ISO 7743, there are two procedures to characterize specimens in compression mode. Differences in the properties of these materials between lubricated and nonlubricated conditions must be considered if devices such as vibration absorbers and isolators are to be developed. With lubrication, compression is said to be uniaxial and homogeneous, thus material properties can be obtained. Without lubrication, tests are easier to perform but results are strongly dependent on the piece shape. In this study isotropic and anisotropic MREs with iron particle volume concentrations of 10, 20, 30 and 40% are tested under different strain amplitudes, prestrain and magnetic fields for a frequency range up to 300 Hz, with and without lubrication. Important design parameters like amplitude, frequency and magnetic field dependency are showed to be dependent on lubrication.
  • Autores: Blanco Mula, Blas (Autor de correspondencia); Errandonea Aranibar, Itxaro; Beltrán Calaff, Sergio; et al.
    ISSN: 0094-114X Vol.171 2022 págs. 104742
    The monitoring of overhead contact lines (OCL) is a key part of railway infrastructure maintenance. This paper proposes a methodology to assess the lateral geometry of contact wire, the so-called stagger, by using the dynamic response of a pantograph. The methodology is tested in a validated virtual environment that resembles the behaviour of the pantograph when it interacts with the OCL. A signal processing is developed to define features relating the lateral position of the contact wire with the vertical acceleration of the contact strip. It is demonstrated that these features have a clear and close connection with the lateral position of the contact wire. Subsequently, model-driven machine learning algorithms are defined using these features to address the OCL stagger prediction and the detection of out-of-range lateral displacement due to a faulty steady-arm. The methodology shows a good prediction performance in the estimation of the stagger amplitude/central position and the steady-arms diagnosis. The prediction of the stagger amplitude is performed with a root-mean-square error of 4.7(10) mm. In addition, the area under the Precision-Recall curve is 0.952 CI95 [0.940, 0.962] for the steady-arms diagnosis.
  • Autores: Blanco Mula, Blas (Autor de correspondencia); Gil-Negrete Laborda, Nere; Kari, L.; et al.
    ISSN: 0042-3114 Vol.60 N° 6 2022 págs. 1993 - 2017
    Rail accelerations can be used on the defect detection and health monitoring of railway vehicle and track components; therefore, mathematical models that predict this response are of interest for reproducing its behaviour in a wide range of situations. The numerical track models based on the Timoshenko beam theory introduce a non-physical response, which is especially noticeable in the rail accelerations. It is due to the lack of dynamic convergence of the Timoshenko finite element (FE). This paper addresses this phenomenon employing an enhanced formulation of the Timoshenko FE that includes internal degrees of freedom (iDoF). The iDoF shape functions are derived from the Timoshenko beam dynamic governing equations. Firstly, the formulation is presented, and its performance is compared with a similar Timoshenko FE formulation. Secondly, the proposal is assessed in the dynamic modelling of railway track structures. The use of iDoF efficiently corrects the non-physical response of rail accelerations by improving the FE dynamic convergence. Subsequently, a filtering criterion for accelerations is proposed, which removes the remaining non-physical response while guaranteeing the conservation of coherent frequency content. Finally, practical cases are simulated for which the proposed methodology is proved to be more efficient and reliable than the standard approach.
  • Autores: Erenchun, A. (Autor de correspondencia); Prieto Rocandio, Borja; Artetxe Ballejo, Gurutz; et al.
    ISSN: 0964-1726 Vol.31 N° 9 2022 págs. 95005
    In this article, the compression characterization of silicon-based magnetorheological elastomers is addressed, emphasizing the difficulties associated to the test set-up in order to obtain accurate results of the behaviour of the material. Measurement errors associated to friction and vibration coupling due to design flaws in the electromagnet are solved by providing guidelines on an adequate electromagnet layout. The designed electromagnet allows conducting compression dynamic tests up to 300 Hz in specimens of dimensions 40 x 40 x 8 mm(3), reaching magnetic flux densities in the order of 1000 mT and showing the expected increase in the dynamic stiffness. Additionally, the electromagnet might be used in the manufacturing and curing of anisotropic magnetorheological compression specimens.
  • Autores: Rodríguez De Arana, Borja (Autor de correspondencia); Bergara, A.; Gil-Negrete Laborda, Nere; et al.
    ISSN: 0013-7944 Vol.276 2022 págs. 108896
    In this work the influence of considering wheel-rail contact creepages on fatigue crack growth rates due to Rolling Contact Fatigue (RCF) is studied. For this purpose, the FASTSIM algorithm, which considers the moving complex pressure distribution with slipping and adhesion zones of the wheel-rail contact patch, has been implemented in Abaqus using FORTRAN code subroutines. The developed methodology has been validated with a 60E1 rail profile model which uses XFEM, by comparing the obtained Stress Intensity Factors (SIFs) and sub-surface shear stresses with numerical results available in the literature. Finally, the RCF crack propagation analysis of a 60E1 rail profile with different contact conditions has been performed using the XFEM. The obtained results justify the necessity of considering contact creepages on contact shear stresses for crack growth analysis.
  • Autores: Rodríguez De Arana, Borja (Autor de correspondencia); San Emeterio Odriozola, Albi; Alvarado Videira, Unai; et al.
    ISSN: 2076-3417 Vol.11 N° 3 2021 págs. 1026
    Rolling contact fatigue (RCF) is a common cause of rail failure due to repeated stresses at the wheel-rail contact. This phenomenon is a real problem that greatly affects the safety of train operation. Preventive and corrective maintenance tasks have a big impact on the Life Cycle Cost (LCC) of railway assets, and therefore cutting-edge strategies based on predictive functionalities are needed to reduce it. A methodology based on physical models is proposed to predict the degradation of railway tracks due to RCF. This work merges a crack initiation and a crack growth model along with a fully nonlinear multibody model. From a multibody assessment of the vehicle-track interaction, an energy dissipation method is used to identify points where cracks are expected to appear. At these points, crack propagation is calculated considering the contact conditions as a function of crack depth. The proposed methodology has been validated with field measurements, conducted using Eddy Currents provided by the infrastructure manager Network Rail. Validation results show that RCF behavior can be predicted for track sections with different characteristics without the necessity of previous on-track measurements.
  • Autores: Prieto Rocandio, Borja; Satrustegui de Legarra, Marco (Autor de correspondencia); Elosegui Simón, Ibon; et al.
    ISSN: 1751-8660 Vol.14 N° 10 2020 págs. 1974 - 1983
    This study presents the electromagnetic, thermal and mechanical analysis of a 750 kW, 1200 rpm, 690 V surface permanent magnet motor aimed at marine propulsion (azimuth thruster). Based on a preliminary machine design, key electromagnetic design aspects including magnet demagnetisation and magnet loss reduction by tangential and axial segmentation are assessed. Then, three different cooling solutions are evaluated via computational fluid dynamics simulations combining the use of a water-jacket surrounding the stator, wafters attached to the rotor structure and the addition of an inner fan. Subsequently, the dynamic design analysis method is applied in order to check the machine's response to shock loadings due to underwater explosions. Finally, a machine prototype is successfully manufactured and tested, showing the proper fulfilment of the design requirements.
  • Autores: Gil-Negrete Laborda, Nere; Nieto Fernández, Francisco Javier; Apezetxea Sánchez, Itziar; et al.
    Libro: Constitutive Models for Rubber XI
    ISSN: 978-0-367-34258-6 2019 págs. 560 - 565
    Rubber suspension elements suffer from oxidative ageing, resulting in a change of their mechanical behaviour. For the particular case of suspension elements of vehicles, ageing mainly increases the quasi-static and dynamic stiffness of the bushings. This influences the dynamic behaviour of the vehicle throughout its operational life, so being able to predict the changes in stiffness becomes of paramount importance. This investigation studies the influence of oxidative ageing on the mechanical properties of two natural rubber compounds that are commonly used to manufacture suspension bushings. Quasi-static and dynamic tests are conducted in tensile and compression specimens, both in non-aged and aged conditions, assessing the changes in the quasi-static stress/strain curves and in the dynamic Young's modulus. Samples are introduced in the oven for different time spans and five ageing temperatures. Accelerated thermal-ageing test results are afterwards extrapolated by using the Arrhenius approach.

Proyectos desde 2018

  • Título: Gemelos digitales ferroviarios: Transferencia de conocimiento entre modelos físicos y modelos derivados de datos
    Código de expediente: PUE_2023_1_0005
    Investigador principal: NERE GIL-NEGRETE LABORDA.
    Convocatoria: Proyectos de investigación Universidad-Empresa 2023-2024
    Fecha de inicio: 01-06-2023
    Fecha fin: 31-12-2024
    Importe concedido: 50.000,00€
    Otros fondos: -
  • Título: Nuevas tecnologías para la inspección de infraestructuras críticas en el sector del transporte, TCRINI2
    Código de expediente: KK-2023-00029
    Investigador principal: NERE GIL-NEGRETE LABORDA.
    Convocatoria: ELKARTEK 2023. Programa de Ayudas a la Investigación Colaborativa en áreas estratégicas
    Fecha de inicio: 01-03-2023
    Fecha fin: 31-12-2024
    Importe concedido: 97.922,00€
    Otros fondos: -