| 摘要 |
The subject matter of the present invention is a method for measuring the Poisson's ratio and the residual stress of any material, that is, a metal, ceramic, polymeric, crystalline or amorphous material, in the form of a bulk material or surface coating. |
| 主权项 |
1. A method for measuring the Poisson's ratio and the residual stress in materials with a surface residual stress field, comprising:
predisposing a sample of material with a surface residual stress field; removing two first parallel strips of material from a surface of the sample wherein there is defined an orthogonal Cartesian plane defined by an x-axis and a y-axis; measuring the strains, at least along the x-axis (Δε(I)x) and the y-axis (Δε(I)y), of the sample of material (1) on said surface; removing from said surface of the sample, two second parallel strips of material perpendicular to said two first parallel strips; measuring the strains, at least along the x-axis (Δε(II)x) and the y-axis (Δε(II)y), of the sample of material on said surface; and calculating, following complete relaxation of the above-mentioned surface residual stresses, that is, for values of h/d greater than 1.2, the Poisson's ratio of the sample of material by means of the following formula:Δɛx(II)Δɛx(I)|hd>1.2=11+v wherein v, h, and d represent the Poisson's ratio, the height of each one of said strips, and the distance between the two first parallel strips, respectively. |
