Anisotropy In Sheet Metal

Anisotropy includes elastic and plastic anisotropy.

Anisotropy in sheet metal.

A general elasto plastic finite element formulation based on incremental deformation theory for planar anisotropy and its application to sheet metal forming int. The anisotropy of young s modulus in cold rolled sheets of binary cu zn alloys tans. Figure 15 the deformation of the grid pattern and the tearing of sheet metal during forming. In cold rolled sheets elastic deformation is much smaller compared with the plastic deformation so only the anisotropic plasticity is nor mally considered.

B forming limit diagrams fld for various sheet metals. Anisotropy is an important factor in sheet metal forming. A method to include the distribution of strains in the identification of the planar anisotropy of sheet metals is proposed. Metal matrix composites with aligned fibres may have highly directional stiffness and strength properties 1 but their utilisation at present is rather little and they will not be considered further here.

19 1977 505. The method includes the optical measurement of strains on a flat specimen with a varying cross section and an inverse parameter identification scheme which minimizes the differences between the numerical simulation results and the experimental measurements by using. The type of plastic anisotropy usually desired in sheet metal forming is that the sheet is isotropic in the plane and. It is also worth mentioning here that the efforts currently under.

Planar anisotropy if by performing experiments on the sheet it is found that the measured r value is unchanged with orientation the sheet is said to have planar anisotropy. Although the major strain is always positive stretching the minor strain may be either positive or negative. In other words the material will react differently to stress applied in one direction than it would to the same stress applied in a different direction. In all other cases anisotropy to some degree is to be expected.

R is the normal anisotropy of the sheet as described in section 4. If r 1 then the sheet is of course isotropic 9 22 2015 39 40. Anisotropy is the directional variation of mechanical properties. A theory of plastic anisotropy based on a yield function of fourth order int.

In circular parts asymmetric forming and earing will be observed. Aime 236 pp489 495 1966. Sheet metal manufacturers do not routinely use online inspection techniques to monitor the texture of the metal as it is produced and most tend to perform x ray pole figure 1 2 spot checks on the final product.