0000000000846420
AUTHOR
Bruno Martin
Modélisation numérique avec apport de matière du soudo-brasage des assemblages hétérogènes acier/aluminium
This study deals with the numerical simulation of heterogeneous brazing of steel / aluminium alloy sheets by CMT process. The difference between the linear expansion coefficients of these materials generates high deformations and residual stress. The addiction of brazing material is simulated. A validation the model is made in the simplest case of a sheet of aluminium alloy with a brazing bead. Comparisons are made between numerical and experimental results on out-of-plane displacements of steel / aluminium assembly.
Etude numérique et expérimentale de l'assemblage acier aluminium par soudo-brasage
Dans cet article nous étudions le soudo-brasage de tôles d'acier et d'aluminium (par la technique CMT, assemblage à clin). Ces métaux ont des coefficients de dilatation thermique différents, ce qui provoque des déformations, d'où des contraintes mécaniques élevées. Des expériences sur des éprouvettes, une simulation numérique thermomécanique sont menées en parallèle afin de mieux comprendre ces aspects thermiques et mécaniques dans le but de minimiser la déformation de l'assemblage.
Acoustic properties of plates with unevenly distributed macro perforations backed by woven meshes
A hybrid model describing the acoustic properties of plates with macro-perforations that can be unevenly distributed on the plate surface and backed by woven or precision woven meshes with microscopic perforations is proposed. The plate perforations may be of circular or rectangular shapes. Since the perforated plate may not necessarily be considered as an equivalent fluid, its surface impedance is calculated by the Maa model [Noise Control Eng. J. 29, 77-84 (1987)], whereas the Johnson-Champoux-Allard model [J. Appl. Phys. 70, 1975-1979 (1991)] is used for the mesh. It is observed that the absorption of the carrying plate seems to depend on the hydraulic diameter of the perforations and no…