Papers by Keyword: Material Anisotropy

Abstract: The earing profile of cylindrical cups is mainly dictated by the in-plane anisotropic behavior of the metal sheet. Nevertheless, for materials with a strong anisotropic behavior the contact conditions between the blank and the blank-holder can also affect the material flow due to the non-uniform distribution of the contact forces. The main objective of this study is to numerically assess the influence of the friction conditions on the cup earing profile using the AA3104 aluminum alloy. The strong anisotropy of the r-values of this material leads to a non-uniform thickness distribution along the circumferential direction of the flange, resulting in increased thickening in the transverse direction. The effect of the friction coefficient on the earing profile is approximately 4 times larger in the transverse direction than in the rolling direction.

Abstract: This paper discusses relations between structure of bi-material samples in 2D and their anisotropic indices and mechanical properties. The bi-material sample is designed to be close to masonry structure. Different ratios of elastic moduli of material are studied and computed material parameters are given.

Abstract: This research paper deals with the influence analysis of the conventional metal spinning parameters (tool path profile tpp, tool feed f and mandrel rotational speed n) on the wall heights and the surface roughness Ra of the cylindrical-shaped spun parts measured in various directions with respect to the material rolling direction. Experimental research was carried out according to the 3-level full factorial design of experiment (DoE). Experimental study was also statistically analyzed by the ANOVA method. It was observed that tool path profile is a process parameter which has the most significant impact on the spun cup height and the surface finish, as well.

Abstract: The effect of the grain orientation of the stainless steel AISI 304 and the effect of the indenter orientation on the indentation moduli was numerically studied by means of the finite element method. The contact areas were evaluated numerically and the indentation moduli was determined according to the Oliver-Pharr method. As a result, the crystallographic orientations in which the indenter orientation plays the most important role were identified. However, the observed indentation moduli variation is within the scatter of the experimental data in practical applications.

Abstract: A comparative study of different material modeling strategies in deformability analysis of rectangular cups is presented in this paper. The article focuses on application of dynamic explicit and static implicit approaches in Finite Element Methods (FEM) for metal forming simulation where different material models and contact conditions with friction are involved. The simulated results are verified using results from experimental study of the deformation on the same material. Further, a comparison between a quadratic Hill anisotropic yield criterion and von Mises yield criterion with isotropic hardening has been studied. The results confirm that the dynamic explicit method is more efficient in simulating sheet metal forming processes. The study shows also that the finite element analysis undoubtedly gives good approximate numerical results to real processes when the material and friction anisotropy are considered.

Abstract: A theoretical analysis on the variation regularity of cutting force caused by the material anisotropy with different orientation of KDP is analyzed firstly; influence and regularity of the variation are obtained. Analysis result shows that the crystal anisotropy of KDP is an important factor in obtaining the super-smooth surface. Then experiments are realized on the machine tool, results afford the variation regularity of cutting force caused by the anisotropy with different orientation of KDP, which certifies the correctness of this theoretical analysis. For ultra-precision machining of the KDP at large negative rake diamond cutter (-45°) and the optimal parameters, the super-smooth surface (rms is 8.702 nm, Ra is 6.895 nm) can be obtained on the plane (001).