Date of Award
Size effects play a significant role in metal processing when the specimen dimensions are reduced. In this study, influence of size effects were investigated on two problem specific processes. First, numerical simulations of a small-scale forward extrusion with varying grain size were performed for both 2D and 3D cases. Here, grains were assigned to non-homogeneous properties in a random fashion. The computational geometry was obtained from Voronoi tessellation in MATLAB, and python-scripting in ABAQUS. Then the effects of size and property non-homogeneity were investigated. Second, a numerical model was simulated to predict final form shapes, punch load requirement, and thickness distribution of hemispherical bowl-shaped forming. The die, punch and cover plate were fabricated using stereolithographic apparatus (SLA). Numerically obtained punch load requirement, thickness distribution, von-Mises contours, and equivalent plastic strain contours were compared for different thickness specimens. Finally, the models were validated by experimental results.
Mondal, Debabrata, "Size Effects in Small Scale Forward Extrusion and Metal Forming" (2019). University of New Orleans Theses and Dissertations. 2675.