Publications

2026

• Modal experimental continuation of an aircraft during ground vibration test
  
  • Chukwu Augustus
  • Stephan Cyrille
  • Touzé Cyril
  • Doaré Olivier
  , 2026. Phase-locked loop experimental continuation method is extended to multi-input multi-output testing, for the identification of the nonlinear dynamics of an aircraft during ground vibration test. More specifically, backbone curve tracking in moderately nonlinear regimes is investigated. Force appropriation and phase control over multiple excitation points are presented, and particular attention is devoted to introduce weighted mode purity indices, to robustly assess the nonlinear mode isolation. A full-scale aircraft is used to illustrate the methods, revealing the benefits that can be obtained for the identification of nonlinear characteristics. (10.2514/6.2026-4777)
  DOI : 10.2514/6.2026-4777
• Automated far-field sound field estimation combining robotized acoustic measurements and the boundary elements method
  
  • Pascal Caroline
  • Marchand Pierre
  • Chapoutot Alexandre
  • Doaré Olivier
  Acta Acustica, EDP Sciences, 2026. The identification and reconstruction of acoustic fields radiated by unknown structures is usually performed using either Sound Field Estimation or Near-field Acoustic Holography techniques. The latter turns out to be especially useful when data is only available close to the source, but information throughout the whole space is needed. Yet, the lack of amendable and efficient implementations of state-of-the-art solutions, as well as the laborious and often lengthy deployment of acoustic measurements continue to be significant obstacles to the practical application of such methods. The purpose of this work is to address both problems. First, a completely automated metrology setup is proposed, in which a robotic arm is used to gather extensive and accurately positioned acoustic data without any human intervention. The impact of the robot on acoustic pressure measurements is cautiously evaluated, and proved to remain limited below 1 kHz. The Sound Field Estimation is then tackled using the Boundary Element Method, and implemented using the FreeFEM software. Numerically simulated measurements have allowed us to assess the method accuracy, which matches theoretically expected results and proves to remain robust against positioning inaccuracies, provided that the robot is carefully calibrated. The overall solution has been successfully tested using actual robotized measurements of an unknown loudspeaker, with a reconstruction error of less than 30 %. (10.1051/aacus/2026017)
  DOI : 10.1051/aacus/2026017
• Influence of pressure on mandibular angiosomes: What implications for decellularization?
  
  • Serra Corentin
  • Monchaux Romain
  • Salmon Benjamin
  • Nokovitch Lara
  • Kadlub Natacha
  • Boisson Jean
  BONE, Elsevier, 2026, 203. <div><p>The vascularization of bone still holds several unknowns, crucial to future developments in reconstructive surgery: both for bone transplantation and decellularized allograft. This study introduces a novel method to analyze pressure-dependent vascular territories in the human mandible, with direct implications for the optimization of decellularization by perfusion protocols. Traditional anatomical approaches have struggled to delineate perfusion territories due to the complexity of multiple arterial inputs and the dynamic nature of blood flow. Our methodology integrates pressure-controlled perfusion with 3D imaging to map vascular distribution within the mandibular bone under varying perfusion pressures. We conducted controlled perfusions on human cadaveric mandibles, progressively increasing pressure while monitoring the expansion of perfused territories using contrast-enhanced cone beam computed tomography. A custom segmentation pipeline allowed for the reconstruction of pressure maps detailing the minimal pressure required to perfuse different regions of the mandible. Our results demonstrate a low-pressure anastomosis of the maxillary artery to the facial artery through the mental artery, suggesting the equivalence of intraosseous territories, followed by a radial perfusion pattern from the inferior alveolar artery, with increasing resistance at the cortical bone. Perfusion saturation was achieved at approximately 100-125hPa, in accordance with physiological arterial pressures. Furthermore, cortical bone exhibited higher perfusion thresholds than cancellous bone, emphasizing differential vascular resistance across bone structures. These findings suggest that pressure-driven perfusion analysis can provide crucial insights into bone vascularization. By optimizing pressure parameters, it may be possible to achieve more effective decellularization by perfusion in massive bone allografts, improving graft integration and long-term viability. This study also underscores the need for pressure-controlled anatomical studies, as perfusion territories vary significantly with applied pressure, challenging traditional static angiosoma models. Future research should explore the applicability of these findings in living tissues and refine decellularization techniques based on controlled perfusion dynamics.</p></div> (10.1016/j.bone.2025.117733)
  DOI : 10.1016/j.bone.2025.117733
• Modal Homogenization of High-Contrast Mie Metasurfaces: From Symmetry Control to Fano, ATS, and Bianisotropic Responses
  
  • Maurel Agnès
  • Pham Kim
  • Lebbe Nicolas
  , 2026. We develop an asymptotic homogenization theory for high-permittivity Mie-resonant metasurfaces illuminated in transverse-electric (TE) polarization. In the subwavelength resonant regime, the metasurface is replaced by an effective interface equipped with frequency-dependent transmission conditions involving three surface susceptibilities (γee, γmm, γem) that fully govern reflection and transmission. A central ingredient is a so-called Static–Dynamic Cell Eigenproblem (SD-Cell EP) posed on the unit cell, coupling a dynamic Helmholtz equation inside the inclusion to a static Laplace equation outside. Its real eigenvalues and eigenmodes yield a modal decomposition of the effective parameters, each resonance contributing as a simple pole. This structure naturally leads to reduced descriptions (single-mode Lorentz, weakly coupled two-mode Fano, and strongly coupled Autler– Townes-type models) that retain physical transparency while remaining quantitatively accurate. For symmetric (rectangular) inclusions, the theory recovers purely electric or magnetic resonances and their transition from Lorentzian to Fano and Autler–Townes behavior. For asymmetric (triangular) inclusions, symmetry breaking activates electromagnetic coupling and turns the metasurface into a reciprocal bianisotropic reflector, enabling strongly asymmetric scattering and, in the presence of weak loss, nearly perfect one-sided absorption.
• Microscale stored energy as a fatigue indicator for NiTi shape memory alloys via synchrotron X-ray diffraction
  
  • Ju Xiaofei
  • Moumni Ziad
  • Borbély András
  • Guo Shuaichen
  • Zhang Yahui
  • Zhong Shengyi
  Materials Science and Engineering: A, Elsevier, 2026, 949, pp.149368. Although fatigue is closely related to microstructural changes, current fatigue criteria for shape memory alloys (SMAs) fail to account for this information due to the lack of research on quantifying microstructural defects associated with fatigue. In this study, we introduce local stored energy as a quantifiable parameter that reflects microstructural evolution and demonstrate its effectiveness as a reliable fatigue indicator. Ex-situ synchrotron X-ray diffraction tests were conducted on a series of NiTi specimens subjected to cyclic loading and stopped at different fatigue stages. The results revealed inhomogeneous microstructures along the gauge section, characterized by residual R-phase accumulation, defect density, and residual stress in active zones. These microstructural changes, resulting from localized deformation, were quantified by local stored energy at the microscale via X-ray peak analysis. Consistent with these inhomogeneous microstructures, the distribution of local stored energy was uneven, with maximum values in active zones where fatigue cracks preferentially occur. As fatigue progressed, local stored energy in these zones increased, eventually stabilizing at a steady state. This steady state exhibited a negative correlation with fatigue lifetimes, where higher loading frequencies resulted in increased stored energy and shorter lifetimes. These findings validate local stored energy as a crucial fatigue indicator, paving the way for development of a physically-grounded fatigue criterion based on this quantity. (10.1016/j.msea.2025.149368)
  DOI : 10.1016/j.msea.2025.149368
• Multi-physics investigation on the influence of impurity elements and scanning parameters on the surface topography in laser powder bed fusion
  
  • Zhai Xingyue
  • Moumni Ziad
  • Zhang Zhidong
  • Li Feifan
  • Wang S
  • Gu Xiaojun
  • Zhu Jihong
  • Zhang Weihong
  Journal of Manufacturing Processes, Society of Manufacturing Engineers, 2026, 159, pp.18-38. Surface topography critically governs the mechanical performance-particularly fatigue resistance-of components fabricated via laser powder bed fusion (LPBF). To advance the understanding of how parameters govern surface formation, a comprehensive multi-physics model was developed, integrating random powder deposition (Discrete Element Method), laser-material interaction and melt pool (MP) dynamics (Finite Volume Method). The framework integrates surface-active elements with a strongly coupled laser tracing model, leading to two critical advances: first, it provides new insights into the role of surface-active elements in MP dynamics; second, it successfully reproduces, the complex formation mechanisms of varying surface topography in multi-track scans by constant surface-active elements: 1) impurity effects: explicitly modeling sulfur and oxygen interactions within the MP, and reveal these elements substantially degrade surface quality through complex thermo-physics mechanisms. Quantitative analysis reveals sulfur exerts a 2.74x stronger influence on surface peak formation than oxygen when concentrations decrease tenfold (S: 0.3 -&gt; 0.03%; O: 0.1 -&gt; 0.01%), establishing its dominance in surface topography evolution. However, at ultralow oxygen-sulfur concentrations, surface topography converges to identical configurations. 2) scanning parameter effects: a coupled analysis of scanning parameter effects-encompassing strategy, speed, and hatch spacing-on non-uniform temperature field evolution is conducted, evaluating-i): energy absorptivity dynamics, ii) surface-induced porosity, iii) inter-track interaction mechanisms, iv) Plateau-Rayleigh instabilities and v) interaction of melt rate, melt flow velocity, inertia and surface tension on surface topography. This study reveals that localized peaks within the MP disrupt laser beam reflection, altering MP dynamics. Furthermore, irregular surface peaks and valleys contribute to the formation of various surface pore types. Critically, during multi-track process, the coupling between scanning strategy and speed generates heterogeneous thermal fields that significantly alter subsequent surface evolution. Our paper provides theoretical guides to help users of additive manufacturing optimize the topography of parts. (10.1016/j.jmapro.2026.01.011)
  DOI : 10.1016/j.jmapro.2026.01.011