Finite element simulation of semi-finishing turning of Electron Beam Melted Ti6Al4V under dry and cryogenic cooling

open6noIn the last few years, important step forwards have been made on Finite Element Simulation of machining operations. Wrought Ti6Al4V alloy has been deeply investigated both numerically and experimentally due to its wide application in the industry. Recently, Additive Manufacturing technologies as the Electron Beam Melting and the Direct Melting Laser Sintering are more and more employed in the production of biomedical and aeronautical components made of Ti6Al4V alloy. Fine acicular microstructures are generated by the application of additive manufacturing technologies, affecting the mechanical properties and the machinability. By the consequence, this peculiarity has to be considered in modelling the material behaviour. In this work, a numerical analysis of cylindrical external turning on Electron Beam Melted (EBM) Ti6Al4V alloy is presented. A Johnson-Cook constitutive equation was implemented as a flow stress model and adapted with respect to the wrought Ti6Al4V alloy. The model was calibrated and validated through the cutting forces and temperatures measurements acquired under dry and cryogenic lubricating conditions.openBordin, A; Imbrogno, S.; Rotella, G.; Bruschi, S.; Ghiotti, A.; Umbrello, D.Bordin, Alberto; Imbrogno, S.; Rotella, G.; Bruschi, Stefania; Ghiotti, Andrea; Umbrello, D

Dynamic Model for Simulating Motion of the Right Ventricle

This report documents all the research, ideation, and mockups used to determine right ventricle motion and develop a system capable of reproducing that motion on a tissue sample. The model is intended for evaluating anchoring systems being developed by Edwards Lifesciences for use with tricuspid valve therapies. Several design solutions were considered for the primary functions of recreating motion of the right ventricle and attaching tissue to the device. From these ideas a primary means of producing motion and attaching tissue was selected. These ideas were then developed over the course of a school year to become the final system hardware delivered to the project sponsor. This document covers the design process including multiple iterations both in CAD and of structural prototypes. The document concludes by discussing the final hardware and the next steps proposed to improve upon the final design

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

THE CNC VIRTUAL AS TEACHING AND TRAINING AID OF CNC PROGRAMMING

CNC machine tools is the most important practical means of teaching and training of CNC Programming in Vocational High School. Its relatively-high price causes the incapabibilty of the school for getting it, so the teaching of CNC programming in Vocational High School mostly doesn’t use CNC machine. The effect is many students can’t reach the standard competence of applied CNC programming. The unavailability of CNC machine tools in teaching of CNC programming in Vocational High School is treated by using CNC Simulator. The CNC Simulator consist Virtual CNC, and CNC Machine Simulator. It’is a media to simulate of NC Part Program execution..The simulation of NC Part Program execution are displayed tool path a machining process at monitor. NC Part Program has been simulated can be sent to unit control of CNC Machine Simulator. Implementation of CNC Simulator in teaching and training of CNC programming begins from building CNC Virtual. The CNC Virtual is a software which provides a visual effect of environment of CNC machine in the monitor. The building uses Research and Development (R&D) method. Implementation of CNC Simulator in teaching of CNC programming shows; (1) the students are very interested and excited to use the virtual CNC which provides a visual effect of environment of CNC machine in the monitor, actively trying the simulation of numpad virtual in the monitor, inputting data on the panel virtual, and making simulation or execution of the CNC program at CNC Machine Simulator, (2) the students practice to make and execute the CNC programming individually in the classroom or outdoor class. (3) CNC Virtual can be used as teaching and training media classically (in classroom), individually learning, even e-learning

Shoe last machining using virtual digitising

Shoe lasts are the moulds used in the footwear industries in order to mount the shoe. Most of the machines used in the sector to make lasts are simply mechanical copiers. CAD/CAM systems have just arrived to the shoe last market but its accuracy and efficiency is not better than traditional machines, for this reason new systems have difficulty to implant. Presented in the paper there is a tool path generation algorithm that takes the advantages of traditional copier systems that do not fulfil the CNC standards. The tool path is computed from a “virtually digitised” model of the last surface. The algorithm is then analysed in terms of computing cost and accuracy and refined by applying a series of optimisations. Some computer architectures are proposed in order to reduce the computation time. The proposed algorithm has been successfully implemented in a commercial CAD/CAM system specialised in shoe last making. Finally, some illustrative examples are shown

Development of synchronverter control for induction motor connection

More and more attention has been paid to the energy crisis due to the increasing energy demand from industrial and commercial applications. The utilization of renewable energy considered as one of the most promising electrical energy sources, which has grown rapidly in the last three decades. In this day and age, many power converter techniques have been developed to integrate renewable energy with the electrical grid. In this work, there is a new technical control is known as synchronverter control which is using the synchronous generator mathematical equations as a reference. This synchronverter control is connected with DC-AC three phase inverter to work as controller of output power to feed the load. In this control strategy, the output current of the controllable inverter is controlled by a feedback load current according to the current reference. The synchronverter technology has been applied to control the inverter for the induction motor connection. An experimental setup based on DSP (Digital Signal Processing) and dc drive board have been designed to implement the open and closed loop experiments. All experiments have been implemented on a test rig based on Matlab 20013a/simulink software and Code Composer Studio V6.0 to demonstrate the excellent performance of the proposed control strategies with stability of the system, sinusoidal currents and good dynamics. Finally, an improve control strategy based on the synchronverter control technology has been tested for three phase inverter for renewable energy applications to make the whole system behave as a synchronous generator

Model Based Prediction Approach for Internal Machine Tool Heat Sources on the Level of Subsystems

AbstractModern machine tools are highly sophisticated mechatronic systems. Each subsystem's energy efficiency is important regarding thermal effects of the machine: Losses in the subsystems are mainly heat sources, causing temperature gradients and thermal elongation. Knowledge about the internal heat sources is therefore mandatory for high precision machining, as well as for the design of compensation strategies. This paper presents a modeling approach to estimate the heat release of machine tool subsystems and predict boundary conditions for thermal models. The simulation results are verified by measurements on an internal cooling system of a lathe.Video abstrac

Procedure for the implementation of a virtual CNC lathe

The paper presents a work executed in the virtual prototyping area. It is described as a procedure for the implementation of a CNC (Computerized Numeric Command) lathe prototype using software for virtual environment development. This procedures focus mainly on the interlocking system (functionality) and geometric model (physical design) of the lathe. Consequently, this work aims at checking the potential and limitations of this graphic interface tool, considering the complexity of the data required for product prototyping in manufacturing or assembly.Eje: Programación de imágenesRed de Universidades con Carreras en Informática (RedUNCI