https://hal.archives-ouvertes.fr/hal-00773015/document

A review on the Mullins effect

https://hal.archives-ouvertes.fr/hal-00120432/document

Raman Spectroscopy of Nanomaterials: How Spectra Relate to Disorder, Particle Size and Mechanical Properties

Failure of metals I : brittle and ductile fracture

Optical full-field measurement methods such as Digital Image Correlation (DIC) are increasingly used in the field of experimental mechanics, but they still suffer from a lack of information about their metrological performances. To assess the performance of DIC techniques and give some practical rules for users, a collaborative work has been carried out by the Workgroup "Metrology" of the French CNRS research network 2519 "MCIMS (Mesures de Champs et Identification en Mecanique des Solides / Full-field measurement and identification in solid mechanics, http://www.ifma.fr/lami/gdr2519)". A methodology is proposed to assess the metrological performances of the image processing algorithms that constitute their main component, the knowledge of which being required for a global assessment of the whole measurement system. The study is based on displacement error assessment from synthetic speckle images. Series of synthetic reference and deformed images with random patterns have been generated, assuming a sinusoidal displacement field with various frequencies and amplitudes. Displacements are evaluated by several DIC packages based on various formulations and used in the French community. Evaluated displacements are compared with the exact imposed values and errors are statistically analyzed. Results show general trends rather independent of the implementations but strongly correlated with the assumptions of the underlying algorithms. Various error regimes are identified, for which the dependence of the uncertainty with the parameters of the algorithms, such as subset size, gray level interpolation or shape functions, is discussed.

/pdf/assessment-of-digital-image-correlation-measurement-errors-dpnymphb5w.pdf

Assessment of digital image correlation measurement errors: methodology and results

Publisher Summary An important failure mechanism in ductile metals and their alloys is by growth and coalescence of microscopic voids. In structural materials, the voids nucleate at inclusions and second-phase particles by decohesion of the particle–matrix interface or by particle cracking. Void growth is driven by plastic deformation of the surrounding matrix. Early micromechanical treatments of this phenomenon considered the growth of isolated voids. Later, constitutive equations for porous ductile solids were developed based on homogenization theory. Among these, the most widely known model was developed by Gurson for spherical and cylindrical voids.

/pdf/ductile-fracture-by-void-growth-to-coalescence-3rgsgx2sfa.pdf

Ductile Fracture by Void Growth to Coalescence

https://hal.archives-ouvertes.fr/hal-00142084/document

Ductile to brittle transition of an A508 steel characterized by Charpy impact test: Part I: experimental results

https://hal.archives-ouvertes.fr/hal-00142085/document

Ductile to brittle transition of an A508 steel characterized by Charpy impact test: Part II: modeling of the Charpy transition curve

Creep damage mechanisms in polyethylene gas pipes

A new ‘Tailor-made’ methodology for the mechanical behaviour analysis of rubber-like materials: II. Application to the hyperelastic behaviour characterization of a carbon-black filled natural rubber vulcanizate

https://hal.archives-ouvertes.fr/hal-03359092/document

R. Piques

Papers

Ductile to brittle transition of an A508 steel characterized by Charpy impact test: Part I: experimental results

Ductile to brittle transition of an A508 steel characterized by Charpy impact test: Part II: modeling of the Charpy transition curve

Creep damage mechanisms in polyethylene gas pipes

A new ‘Tailor-made’ methodology for the mechanical behaviour analysis of rubber-like materials: II. Application to the hyperelastic behaviour characterization of a carbon-black filled natural rubber vulcanizate

Damage and fracture of polyvinylidene fluoride (PVDF) at 20 °C: Experiments and modelling