Grupos Investigadores

Líneas de Investigación

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

Palabras Clave

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

Publicaciones Científicas desde 2018

  • 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, I. (Autor de correspondencia); 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); 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.