A Novel Mathematical Formulation for Density-based Topology Optimization Method Considering Multi-Axis Machining Constraint

This paper proposes a novel density-based method for structural design considering restrictions of multiaxis machining processes. A new mathematical formulation based on Heaviside function is presented to transform the design field into a geometry which can be manufactured by multi-axis machining process. The formulation is developed for 5-axis machining, which can be also applied to 2.5D milling restriction. The filter techniques are incorporated to effectively control the minimum size of void region. The proposed method is demonstrated by solving the compliance minimization problem for different machinable freeform designs. Several two and three-dimensional numerical examples are presented and discussed in detail.

A discrete simulation-based algorithm for the technological investigation of 2.5D milling operations

Many applications are available for the syntactic and semantic verification of NC milling tool paths in simulation environments. However, these solutions – similar to the conventional tool path generation methods – are generally based on geometric considerations, and for that reason they cannot address varying cutting conditions. This paper introduces a new application of a simulation algorithm that is capable of producing all the necessary geometric information about the machining process in question for the purpose of further technological analysis. For performing such an analysis, an image space-based NC simulation algorithm is recommended, since in the case of complex tool paths it is impossible to provide an analytical description of the process of material removal. The information obtained from the simulation can be used not only for simple analyses, but also for optimisation purposes with a view to increasing machining efficiency.

Surface Quality Prediction in Case of Steep Free Form Surface Milling

The machining of free form surfaces is a current and important issue in die and mould industry. Beside the complex geometry, an accurate and productive machining and good surface quality are needed. The finishing milling carried out by a ball-end or toroid milling cutter defines the surface quality, which is characterized by the surface roughness and the tool path trace. The surface quality is defined by the properties of the milling cutter, the type of surface and its position, as well as the cutting parameters. This article focuses on the z-level milling of steep surfaces by 2.5D milling strategy. The importance of the different elements of the tool path is presented, the effect of cutting parameters is investigated, and a formula to predict the surface roughness is suggested.