Numerical Analysis of Influence of Cutting Edge Radius on the Minimum Thickness of the Machined Layer

Possibilities of miniaturization of products are constantly increasing and create numerous technological challenges at the same time. One of the important aspects of the machining process, which is the essence of this work, is the geometry of the cutting tool. This work aims to investigate the influence of three different radius of cutting edge on the minimum thickness of machined layer. The phenomena on a typical incremental step were described using a step-by-step incremental procedure, with an updated Lagrangian formulation. The machining process is considered as geometrical and physical non-linear initial and boundary problem. The finite element method (FEM) and the dynamic explicit method (DEM) were used to obtain the solution. The application was developed in the ANSYS/LS-DYNA system which makes possible a complex time analysis of the physical phenomena: states of displacements, strains and stresses. Numerical computations of the strain have been conducted with the use of methodology which requires a proper definition of the contact zone, without the necessity to introduce boundary conditions. Examples of calculations are presented and show what the depth of cut at a given radius of cutting edge allows achieving a minimum thickness of cutting.

Modeling and Simulation of Metal Forming Processes by XFEM

In this work, 2-D/3-D forming problems (extrusion and deep drawing) are numerically simulated by extended finite element method (XFEM). The updated Lagrangian formulation is used to model the large deformation. The von-Mises yield criterion is used to model the elasto-plastic behavior assuming isotropic hardening. Penalty approach is employed to impose the contact constraints and non–penetration condition at the material interfaces. The level set approach is used for locating the material interfaces. The numerical simulations of two forming problems are presented using developed nonlinear XFEM code.

Effects of Process Parameters on the Formability of Miniature Layered Cups

Based on materials, different punch radii (0.3, 0.35, 0.4, 0.45, and 0.5 mm), two sets of diameter-diameter ratio 1.(.167, 1.25, 1.33, 1.4167, and 1.5) and 2.(1.6, 1.45, 1.33, 1.231, and 1.143), and two sets of depth ratio 1.(1.3, 1.4, 1.5, 1.6, and 1.7) and 2.(2.14, 1.875, 1.67, 1.5, and 1.36) are used for the stamping processes to analyze the simulation and experimental difference in copper sheet-metal (C1100) miniature layered cups. Prandtl-Reuss flow rule is integrated with finite deformation theory and Updated Lagrangian Formulation (ULF) to establish the incremental elastic-plastic deformation Finite Element Method in Coulomb’s Friction Law for simulating the miniature layered cup process. Generalized rmin algorithm is utilized in the forming process for dealing with elastic-plastic behaviors and die contact. From the simulation data, the relationship among deformation history, punch load, and punch stroke, the stress-strain distribution, and the distribution of the thinnest thickness by different punch radii are acquired.

Nonlinear Stability Analysis of Thin-Walled Pier

Shell element was used to simulate thin-walled piers. Mander constitutive model was adopted for analysis about the material nonlinearity. By finite displacement theory the geometric nonlinearity effect was reckoned in stability analysis based on Updated Lagrangian formulation. Nonlinear stability analysis during different construction stages indicates that the stability of pier in cantilever stage is weakest. Considered the dual non-linearity, the stability coefficient descends distinctly.

An Adaptive Remeshing Procedure for Modeling the Clinch Forming Process

This work presents the case of a press clinching commonly met in the industry and denoted as TOX. The mechanical strength of the assembly is highly dependent on the final geometry of the clinched joint and among the numerous parameters which govern the process (applied load, lubrication, sheet thickness, friction, mechanical behavior of materials), the tool geometry plays a major role in the evolution of the final shape of the clinched joint. One of the objectives of this work is to provide an accurate numerical evolution of the final geometry of the clinched joint by the use of an adaptive remeshing procedure including error indicators and field variable transfer built by a meshless technique denoted as Diffuse Approximation. The resolution of the updated Lagrangian formulation is based on a static explicit approach (ABAQUS). Our numerical results are validated in comparison with experimental data.