Miguel Molero

Publications (25) View all

• Source

  Available from: Ursula Iturraran-Viveros

  Article: Accelerating numerical modeling of wave propagation through 2-D anisotropic materials using OpenCL

  Miguel Molero, Ursula Iturrarán-Viveros
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  ABSTRACT: We present an implementation of the numerical modeling of elastic waves propagation, in 2D anisotropic materials, using the new parallel computing devices (PCDs). Our study is aimed both to model laboratory experiments and explore the capabilities of the emerging PCDs by discussing performance issues. In the experiments a sample plate of an anisotropic material placed inside a water tank is rotated and, for every angle of rotation it is subjected to an ultrasonic wave (produced by a large source transducer) that propagates in the water and through the material producing some reflection and transmission signals that are recording by a "point-like" receiver. This experiment is numerically modeled by running a finite difference code covering a set of angles θ∈[-50°, 50°], and recorded the signals for the transmission and reflection results. Transversely anisotropic and weakly orthorhombic materials are considered. We accelerated the computation using an open-source toolkit called PyOpenCL, which lets one to easily access the OpenCL parallel computation API's from the high-level programming environment of Python. A speedup factor over 19 using the GPU is obtained when compared with the execution of the same program in parallel using a CPU multi-core (in this case we use the 4-cores that has the CPU). The performance for different graphic cards and operating systems is included together with the full 2-D finite difference code with PyOpenCL.
  Ultrasonics 01/2013; 53(3):815 - 822. · 1.84 Impact Factor
• Article: Decalcification of cement mortars: Characterisation and modelling

  I Segura, M Molero, S Aparicio, J J Anaya, A Moragues
  Cement and Concrete Composites. 01/2013; 35(1):136-150.
• Source

  Available from: Miguel Molero

  Article: Comparison of phase velocity in trabecular bone mimicking-phantoms by time domain numerical (EFIT) and analytical multiple scattering approaches.

  M Molero, L Medina
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  ABSTRACT: The corrected Waterman-Truell model and the Elastodynamic Finite Integration Technique were used to analyze the ultrasonic wave dispersion in trabecular bones mimicking phantoms. A simple two-phase model of the trabecular bone is assumed; the trabeculae structure and the bone marrow. The phase velocity for frequencies within the range from 400kHz to 800kHz were computed for different scatterer arrays varying their dimensions and number. The theoretical and numerical results were compared to experimental published data, obtained from a mimicking phantom composed by a periodic array of nylon shreds (trabeculae array) immersed in a water tank. Our results showed an excellent consistency when compared to experimental data. The negative dispersions of -8.48m/s/MHz and -9.16m/s/MHz were computed by the multiple scattering method and the numerical approach, respectively, where the latter is closer to the experimental dispersion of -12.09m/s/MHz. Similar result has been reported in the literature, where the dispersion predicted by the Generalized Self-Consistent Method [J. Acoust. Soc. Am. 124 (2008) 4047] is -9.96m/s/MHz.
  Ultrasonics 05/2012; 52(7):809-14. · 1.84 Impact Factor
• Article: Evaluation of freeze-thaw damage in concrete by ultrasonic imaging

  M Molero, S Aparicio, G Al-Assadi, M J Casati, M G Hernández, J J Anaya
  NDT and E International. 01/2012; 52:86-94.
• Source

  Available from: Miguel Molero

  Article: Ultrasonic wave propagation in cementitious materials: a multiphase approach of a self-consistent multiple scattering model.

  M Molero, I Segura, M G Hernández, M A G Izquierdo, J J Anaya
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  ABSTRACT: This paper examines ultrasonic wave propagation through strongly heterogeneous materials such as cementitious materials, and deals meanly with the formulation of a multiphase approach of a self-consistent multiple scattering model, the so-called dynamic generalized self-consistent model (DGSCM) proposed by Yang [J. Appl. Mech. 70(2003) 575-582]. This extended model can describe the influence of the size and volume fraction of aggregates on cementitious materials, as well as the interaction, contribution, and influence of entrapped air voids together with the aggregates on frequency-dependent parameters such as the phase velocity and the attenuation coefficient. To show the performance of this approach, theoretical predictions were compared with experimental ultrasonic measurements over a wide frequency range from several mortar specimens with different features in their microstructure properties and concentrations of aggregates up to 60%. The multiphase approaches of both the DGSCM and the Waterman-Truell model (WT) were also compared. The obtained results of the multiphase DGSCM were found to be significantly better than those obtained from the N-phase WT model for ultrasonic measurements from cementitious materials at high aggregate concentrations. The feasibility of material characterization using the multiphase approach of DGSCM was also discussed.
  Ultrasonics 01/2011; 51(1):71-84. · 1.84 Impact Factor