Nicolas Bochud

Nicolas Bochud
Université Paris-Est Créteil Val de Marne - Université Paris 12 | UPEC · Modélisation et Simulation Multi-Echelle (MSME) - UMR 8208 CNRS

PhD in Civil Engineering and Architecture

About

65
Publications
8,875
Reads
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501
Citations
Additional affiliations
September 2017 - February 2019
Institute Langevin, ESPCI ParisTech, PSL Research University, CNRS
Position
  • Fellow
June 2014 - August 2016
Sorbonne Université
Position
  • PostDoc Position
September 2009 - August 2013
University of Granada
Position
  • PhD Student

Publications

Publications (65)
Article
Full-text available
Photopolymer-based additive manufacturing has received increasing attention in the field of acoustics over the past decade, specifically towards the design of tissue-mimicking phantoms and passive components for ultrasound imaging and therapy. While these applications rely on an accurate characterization of the longitudinal bulk properties of the m...
Article
Full-text available
Functional grading is a distinctive feature adopted by nature to improve the transition between tissues that present a strong mismatch in mechanical properties, a relevant example being the tendon-to-bone attachment. Recent progress in multi-material additive manufacturing now allows for the design and fabrication of bioinspired functionally graded...
Chapter
Recent progress in quantitative ultrasound have sparked increasing interest towards the measurement of long cortical bones (e.g., radius or tibia), because their ability to sustain loading and resist fractures is known to be related to their mechanical properties at different length scales. In particular, applying guided waves for the assessment of...
Article
Full-text available
Nanoporosity in silicon leads to completely new functionalities of this mainstream semiconductor. A difficult to assess mechanics has however significantly limited its application in fields ranging from nanofluidics and biosensorics to drug delivery, energy storage and photonics. Here, we present a study on laser-excited elastic guided waves detect...
Article
Full-text available
The interphase joining tendon to bone plays the crucial role of integrating soft to hard tissues, by effectively transferring stresses across two tissues displaying a mismatch in mechanical properties of nearly two orders of magnitude. The outstanding mechanical properties of this interphase are attributed to its complex hierarchical structure, esp...
Article
Joining soft to hard materials is a challenging problem in modern engineering applications. In order to alleviate stress concentrations at the interface between materials with such a mismatch in mechanical properties, the use of functionally graded interphases is becoming more widespread in the design of the new generation of engineered composite m...
Preprint
Full-text available
Nanoporosity in silicon leads to completely new functionalities of this mainstream semiconductor. A difficult to assess mechanics has however significantly limited its application in fields ranging from nanofluidics and biosensorics to drug delivery and energy storage. Here, we present a study on laser-excited elastic guided waves detected contactl...
Chapter
Structural Health Monitoring (SHM) is an emerging discipline that aims at improving the management of the life cycle of industrial components. The scope of this chapter is to present the integration of nonlinear ultrasonics with the Bayesian inverse problem as an appropriate tool to estimate the updated health state of a component taking into accou...
Article
Full-text available
Recent ultrasound axial transmission techniques exploit the multimode waveguide response of long bones to yield estimates of cortical bone structure characteristics. This pilot cross‐sectional study aimed to evaluate the performance at the one‐third distal radius of a bidirectional axial transmission (BDAT) device to discriminate between fractured...
Article
Full-text available
Nonlinear constitutive mechanical parameters, predominantly governed by micro-damage, interact with ultrasound to generate harmonics that are not present in the excitation. In principle, this phenomenon therefore permits early stage damage identification if these higher harmonics can be measured. To understand the underlying mechanism of harmonic g...
Article
Full-text available
Several studies showed the ability of the cortex of long bones such as the radius and tibia to guide mechanical waves. Such experimental evidence has given rise to the emergence of a category of quantitative ultrasound techniques, referred to as the axial transmission, specifically developed to measure the propagation of ultrasound guided waves in...
Article
Full-text available
A method to recover the elastic properties, thickness, or orientation of the principal symmetry axes of anisotropic plates is presented. This method relies on the measurements of multimode guided waves, which are launched and detected in arbitrary directions along the plate using a multi-element linear transducer array driven by a programmable elec...
Article
Estimating deterministic single-valued damage parameters when evaluating the actual health state of a material has a limited meaning if one considers not only the existence of measurement errors, but also that the model chosen to represent the damage behavior is just an idealization of reality. This paper proposes a multilevel Bayesian inverse prob...
Conference Paper
Elasticguided waves are one of the most promising quantitative ultrasound techniques for the assessment of elastic properties in plate-like structures. Measurements of guided waves, associated with suitable waveguide modeling, can yield accurate estimates of waveguide properties like thickness and stiffnesses. Such a model-based approach requires s...
Article
Full-text available
Recent bone quantitative ultrasound approaches exploit the multimode waveguide response of long bones for assessing properties such as cortical thickness and stiffness. Clinical applications remain, however, challenging, as the impact of soft tissue on guided waves characteristics is not fully understood yet. In particular, it must be clarified whe...
Conference Paper
Ultrasonic guided waves have been proposed as a promising means to evaluate the long cortical bone. However, the complete extraction of all dispersion curves is still challenging. Aiming to enhance the signal-to-noise-ratio (SNR) and improving the ambiguity of mode identification, we propose a multichannel wideband mode selective excitation method....
Conference Paper
Guided wave propagation is at the heart of the axial transmission techniques designed to assess bone health status. The method involves matching observed and predicted dispersion characteristics of guided waves. The strength of the technique is that it can infer more than one bone property from the measured ultrasonic data, such as cortical thickne...
Article
Recent progress in quantitative ultrasound exploit the multimode waveguide response of long bones. Measurements of the guided modes, along with suitable waveguide modeling, have the potential for inferring strength-related factors such as stiffness (mainly determined by cortical porosity) and cortical thickness. However, the development of such mod...
Article
Cortical bone loss is not fully assessed by current Xray methods, and there is an unmet need in identifying women at risk of osteoporotic fracture who should receive a treatment. The last decade has seen the emergence of ultrasound axial transmission techniques to assess cortical bone. Recent axial transmission techniques exploit the multimode wave...
Chapter
Full-text available
This chapter therefore focuses on a key element of NDE systems: a suitable analysis of the captured signals, which may provide useful information to detect, characterize or classify damages. The work developed by the authors on ultrasonic signal processing techniques for testing of composite materials is presented to illustrate the potential of sig...
Chapter
Structural Health Monitoring (SHM) is an emerging discipline that aims at improving the management of the life cycle of industrial components. The scope of this chapter is to present the integration of nonlinear ultrasonics with the Bayesian inverse problem as an appropriate tool to estimate the updated health state of a component taking into accou...
Conference Paper
Despite their desirable mechanical properties, damage propagation in carbon fiber-reinforced polymers (CFRP) due to manufacturing flaws and continued use may particularly be hard to assess. In this work, damage maps are generated to identify the health state of a CFRP plate from ultrasonic signals obtained under C-Scan mode. This configuration allo...
Chapter
Structural Health Monitoring (SHM) is an emerging discipline that aims at improving the management of the life cycle of industrial components. The scope of this chapter is to present the integration of nonlinear ultrasonics with the Bayesian inverse problem as an appropriate tool to estimate the updated health state of a component taking into accou...
Conference Paper
A step forward towards ultrasonic characterization of cortical bone has been recently reached by showing that cortical bone behaves as a waveguide for ultrasound. Measurements of the guided modes dispersion relations, along with appropriate waveguide modeling, have the potential for inferring strength-related factors such as stiffness (determined b...
Conference Paper
Full-text available
The influence of soft-tissue on guided wave measurements for the assessment of cortical bone properties is not fully understood yet. To improve our understanding of the soft-tissue influence on the guided modes propagation characteristics, a series of assemblies of soft tissue- and bone-mimicking phantoms were ultrasonically investigated using the...
Conference Paper
Structural decay of bone is not fully assessed by current X-ray methods, and there is an unmet need in identifying women at risk of fracture who should receive a treatment. The last decade has seen the emergence of ultrasound (US) axial transmission (AT) techniques to assess cortical bone. Recent AT techniques exploit the multimode waveguide respon...
Conference Paper
Full-text available
An ultrasonic evaluation technique for damage identification of layered CFRP structures is presented. This approach relies on a model-based estimation procedure that combines experimental data and simulation of ultrasonic damage-propagation interactions. The CFPR structure, a [0/90]4s lay-up, has been tested in an immersion through transmission exp...
Conference Paper
Full-text available
An ultrasonic evaluation technique for damage identification of layered CFRP structures is presented. This approach relies on a model-based estimation procedure that combines experimental data and simulation of ultrasonic damage-propagation interactions. The CFPR structure, a [0/90]4s lay-up, has been tested in an immersion through transmission exp...
Conference Paper
Full-text available
The cervix is a biochemically active tissue that changes its biomechanical properties in a remodeling process during pregnancy to be prepared for parturition. This maturation process is associated with changes of the mechanical properties of the cervical stroma. Preterm delivery is connected with undesired cervical changes bound to cervical ripenin...
Conference Paper
Full-text available
Preliminar experimental evidence of the feasibility of using the Second harmonic generation to quantify by ultrasonics the constitutive nonlinearity of bone samples is provided. The nonlinear constitutive properties, in the sense of deviation from Hooke's law, are recently being shown to be orders of magnitude more sensitive to micro-damage than th...
Conference Paper
Full-text available
Carbon-fiber reinforced polymers (CFRP) are high performance advanced materials with a growing applicability due to their extreme strength-to-weight and rigidity-to-weight efficiency ratios. One of the major concerns associated with composites is their vulnerability to impact and fatigue damage. The latters may lead to delamination, sub-surface mat...
Conference Paper
Full-text available
Recent works describe the advances in the substitutive organ therapy [1, 2, 3], based on the development of the so-called bio-artificial organs (decellularized organs of human or animal origin), that benefit of their extracellular matrix, and whose cells are substituted through a recellularization process via primary cells that show ability to diff...
Conference Paper
Signal processing has been proven to be an useful tool to characterize damaged materials under ultrasonic nondestructive evaluation. In this work, we hypothesize that the transfer function of multilayered materials for a through-transmission configuration can be represented as a classical all-pole model with sparse coefficients. To test this hypoth...
Patent
Full-text available
19 OFICINA ESPAÑOLA DE PATENTES Y MARCAS ESPAÑA 11 21 Número de publicación: 2 387 770 Número de solicitud: 201130299 51 Int. CI.: G01N 29/00 (2006.01) G01N 33/483 (2006.01) 12 PATENTE DE INVENCIÓN B1 54 Título: DISPOSITIVO Y MÉTODO DE MONITORIZACIÓN DE MUESTRAS. 73 Titular/es: UNIVERSIDAD DE GRANADA (50.0%) Hospital Real, Cuesta del Hospicio s/n 1...
Conference Paper
Full-text available
To respond to the design of a torsion sensor into mechanical ultrasonic tissue applications, it is necessary to use FEM Finite Element Models. Through a simplified analytical model of torsion transducer, we determine the resonant frequency for a torque transducer ultrasonic waves. It is computationally validated. More specifically the idea is to re...
Conference Paper
Full-text available
Quantitative control of tissue processes in bioreactors is an open problem in tissue engineering, aimed at creating artificial tissues and organs. To standardize and optimize the process, it is necessary to control most of the parameters that may vary its effectiveness. We propose to monitor the changes that may suffer the matrix during the process...
Article
Full-text available
The understanding of internal processes that affect the changes of consistency of soft tissue is a challenging problem. An ultrasound-monitoring Petri dish has been designed to monitor the evolution of relevant mechanical parameters during engineered tissue formation processes in real time. A better understanding of the measured ultrasonic signals...
Article
Introduction A multi-scale constitutive model for the nonpregnant cervical tissue is presented. The mechanical response of the cervix is described by a model which takes into account material properties at different structural hierarchies of tissue through a multi-scale coupling scheme. The model introduces the deformation mechanisms of collagen fi...
Conference Paper
Full-text available
The evolution of relevant mechanical parameters during tissue engineering formation processes can provide useful information for their control in real-time, as well as a new dimension in the understanding of internal processes and their final quality. Since ultrasonics are mechanical waves, they are ideally well suited for probing certain mechanica...
Conference Paper
Full-text available
The use of model-based cepstral features has been shown as an ef-fective characterization of damaged materials tested with ultrasonic non-destructive evaluation (NDE) techniques. In this work, we fo-cus our study on carbon-fiber reinforced polymer plates and show that the use of signal models with physical meaning can provide a cepstral representat...
Conference Paper
Full-text available
Anticipate and characterize damages in layered carbon fiber-reinforced polymers (CFRP) is a challenging problem. Non-destructive evaluation using ultrasonic signals is a well-established method to obtain physically relevant parameters to characterize damages in isotropic homogeneous materials. However, due to their structural complexity, composites...
Conference Paper
Full-text available
Anticipating and characterizing damages in layered carbon fiber-reinforced polymers is a challenging problem. Non-destructive evaluation using ultrasonic signals is a well-established method to obtain physically relevant parameters to characterize damages in isotropic homogeneous materials. However, ultrasonic signals obtained from composites requi...

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