Generative feature-based design-by-constraints as a means of integration within the manufacturing industry

The article examines the development of computer aids within manufacturing industry and proposes an alternative approach to the way we design and the designer's role within manufacturing. A feature-based generative design-by-constraints approach is applied, which requires the designer to specify solutions in terms of manufacturing data, which is captured by means of an interactive simulation of machining processes, in which the constraints of equipment, materials and tools are displayed to the designer. The effect of this approach on the integration of all areas within a manufacturing environment is explored, as is the simultaneous design nature of this approach

An Improved Particle Finite Element Method for the Simulation of Machining Processes

Machining is one of the most common and versatile manufacturing processes in industry, e.g. automotive industry and aerospace industry. But classical numerical methods such as the Finite Element Method (FEM) have difficulties to simulate it, because the material undergoes large deformations, large strain, large strain rates and high temperatures in this process. One option to simulate such kind of problems is the Particle Finite Element Method (PFEM) which combines the advantages of continuum mechanics and discrete modeling techniques. In this study we develop the PFEM further and call it the Adaptive Particle Finite Element Method (A-PFEM). Compared to the PFEM the A-PFEM enables insertion of particles and improves significantly the mesh quality along the numerical simulation. The A-PFEM improves accuracy and precision, while it decreases computing time and resolves the phenomena that take place in machining. Because metal cutting involves plastic deformation we resort to the J? flow theory with isotropic hardening. At last some numerical examples are presented to compare the performance of the PFEM and A-PFEM

Dynamic behaviour of β-Ti-15333 in ultrasonically assisted turning: experimental and numerical analysis

The enhanced strength, fatigue life, and corrosion resistance properties of Tialloys have attracted many industries for their utilization in various components exposed to extreme operating conditions. The machining of these alloys using conventional machining techniques is one of the main challenges in its wide application in many components, and there is an obvious demand to analyse the materials' response to these alloys in machining processes by developing simulation-based models. The materials' behaviour used in simulation of machining processes is usually determined by means of Split-Hopkinson- Pressure-Bar (SHPB) setup. A 3D thermo-mechanically coupled Finite-Element (FE) model of SHPB is developed in the current work to analyse materials response of FI-Ti-15333 at the selected temperature, strain rate, and strain. The obtained materials' response to the tested alloys is used in 3D thermo-mechanically coupled FE model of ultrasonically assisted turning and conventional turning at various tested cutting conditions. The developed FE model is used for parametric analysis of fi-Ti-15333 machining, and the obtained FE results are in good agreement with experimental results

FEA modeling of orthogonal cutting of steel: a review

Orthogonal cutting is probably the most studied machining operation for metals. Its simulation with the Finite Element Analysis (FEA) method is of paramount academic interest. 2D models, and to a lesser extent 3D models, have been developed to predict cutting forces, chip formation, heat generation and temperature fields, residual stress distribution and tool wear. This paper first presents a brief review of scientific literature with focus on FEA modelling of the orthogonal cutting process for steels. Following, emphasis is put on the building blocks of the simulation model, such as the formulation of the mechanical problem, the material constitutive model, the friction models and damage laws

Multi-scale simulation of the nano-metric cutting process

Molecular dynamics (MD) simulation and the finite element (FE) method are two popular numerical techniques for the simulation of machining processes. The two methods have their own strengths and limitations. MD simulation can cover the phenomena occurring at nano-metric scale but is limited by the computational cost and capacity, whilst the FE method is suitable for modelling meso- to macro-scale machining and for simulating macro-parameters, such as the temperature in a cutting zone, the stress/strain distribution and cutting forces, etc. With the successful application of multi-scale simulations in many research fields, the application of simulation to the machining processes is emerging, particularly in relation to machined surface generation and integrity formation, i.e. the machined surface roughness, residual stress, micro-hardness, microstructure and fatigue. Based on the quasi-continuum (QC) method, the multi-scale simulation of nano-metric cutting has been proposed. Cutting simulations are performed on single-crystal aluminium to investigate the chip formation, generation and propagation of the material dislocation during the cutting process. In addition, the effect of the tool rake angle on the cutting force and internal stress under the workpiece surface is investigated: The cutting force and internal stress in the workpiece material decrease with the increase of the rake angle. Finally, to ease multi-scale modelling and its simulation steps and to increase their speed, a computationally efficient MATLAB-based programme has been developed, which facilitates the geometrical modelling of cutting, the simulation conditions, the implementation of simulation and the analysis of results within a unified integrated virtual-simulation environment

Numerical methods for the modelling of chip formation

The modeling of metal cutting has proved to be particularly complex due to the diversity of physical phenomena involved, including thermo-mechanical coupling, contact/friction and material failure. During the last few decades, there has been significant progress in the development of numerical methods for modeling machining operations. Furthermore, the most relevant techniques have been implemented in the the relevant commercial codes creating tools for the engineers working in the design of processes and cutting devices. This paper presents a review on the numerical modeling methods and techniques used for the simulation of machining processes. The main purpose is to identify the strengths and weaknesses of each method and strategy developed up-to-now. Moreover the review covers the classical Finite Element Method covering mesh-less methods, particle-based methods and different possibilities of Eulerian and Lagrangian approaches.Postprint (author's final draft

Numerical Methods for the Modelling of Chip Formation

The modeling of metal cutting has proved to be particularly complex due to the diversity of physical phenomena involved, including thermo-mechanical coupling, contact/friction and material failure. During the last few decades, there has been significant progress in the development of numerical methods for modeling machining operations. Furthermore, the most relevant techniques have been implemented in the relevant commercial codes creating tools for the engineers working in the design of processes and cutting devices. This paper presents a review on the numerical modeling methods and techniques used for the simulation of machining processes. The main purpose is to identify the strengths and weaknesses of each method and strategy developed up-to-now. Moreover the review covers the classical Finite Element Method covering mesh-less methods, particle-based methods and different possibilities of Eulerian and Lagrangian approaches

A sensibility analysis to geometric and cutting conditions using the particle finite element method (PFEM)

The (PFEM) is employed to simulate orthogonal metal cutting of 42CD4 steel. The objectives of this work are mainly three: The first one is to validate PFEM strategies as an efficient tool for numerical simulation of metal cutting processes by a detailed comparison (forces, stresses, strains, temperature, etc.) with results provided by commercial finite element software (Abaqus, AdvantEdge, Deform) and experimental results. The second is to carry out a sensibility analysis to geometric and cutting conditions using PFEM by means of a Design of Experiments (DoE) methodology. And the third one is to identify the advantages and drawbacks of PFEM over FEM and meshless strategies. Also, this work identifies some advantages of PFEM that directly apply to the numerical simulation of machining processes: (i) allows the separation of chip and workpiece without using a physical or geometrical criterion (ii) presents negligible numerical diffusion of state variables due to continuous triangulation, (iii) is an efficient numerical scheme in comparison with FEM

Simulation of a finishing operation : milling of a turbine blade and influence of damping

Milling is used to create very complex geometries and thin parts, such as turbine blades. Irreversible geometric defects may appear during finishing operations when a high surface quality is expected. Relative vibrations between the tool and the workpiece must be as small as possible, while tool/workpiece interactions can be highly non-linear. A general virtual machining approach is presented and illustrated. It takes into account the relative motion and vibrations of the tool and the workpiece. Both deformations of the tool and the workpiece are taken into account. This allows predictive simulations in the time domain. As an example the effect of damping on the behavior during machining of one of the 56 blades of a turbine disk is analysed in order to illustrate the approach potential

Simulation of a finishing operation : milling of a turbine blade and influence of damping

Milling is used to create very complex geometries and thin parts, such as turbine blades. Irreversible geometric defects may appear during finishing operations when a high surface quality is expected. Relative vibrations between the tool and the workpiece must be as small as possible, while tool/workpiece interactions can be highly non-linear. A general virtual machining approach is presented and illustrated. It takes into account the relative motion and vibrations of the tool and the workpiece. Both deformations of the tool and the workpiece are taken into account. This allows predictive simulations in the time domain. As an example the effect of damping on the behavior during machining of one of the 56 blades of a turbine disk is analysed in order to illustrate the approach potential