M. Wabner

ABSTRACT A new visualization method for an illustrative visualization of physical parameters in immersive workspaces is presented. Through the newly developed visualization pipeline, FEM results such as stress, temperature and resulting deformation, as well as the underlying constraints can be visualized in virtual and augmented reality applications. Special features are the use of 3D glyphs for mapping stress direction and gradient as well as data preparation and the resulting data format, which was especially developed for use with VR systems. This article demonstrates the current state of VR developments, which were done at the Virtual Reality Center Production Engineering of the Institute for Machine Tools and Production Processes, for improving the analysis of complex FE datasets, and gives an outlook to future research activities.

ABSTRACT This paper reports on a novel electro-hydraulic actuator that attenuates and isolates ground motion to keep dynamic excitations transmitted to machine tools below permissible levels. The first part describes the working principle of the actuator. The actuator is a classic example of a valve-controlled piston. Flow to the actuator is regulated to move the actuator and the machine that the actuator supports to compensate for ground motion experienced by the machine. Dynamics of this electro-hydraulic actuator are described in the second part of the paper. The third part describes experimental characterization of a physical prototype to identify unknown system parameters. Experimentally updated model is coupled to a virtual model of a flexible machine tool in the fourth part. Simulation driven investigations for the controlled transmissibility show the actuator to be effective in a frequency range of 1–100 Hz with case specific attenuations ranging from 5 to 25 dB. The actuator is designed with a high passive stiffness to support inertial loads of the machine. The device can be operated on demand when high precision is required, making it an energy efficient solution.

ABSTRACT This paper presents the dynamic modelling of a novel electro-hydraulic actuator that decouples, attenuates and isolates ground motion to keep dynamic excitations transmitted to machine tools below permissible levels. Closed-loop dynamics are formulated by considering the hydraulic system dynamics as well as the dynamics of the actuator and machine tool. Controlled closed-loop transmissibility shows the actuator to have excellent attenuation of ground vibrations for excitation frequencies of up to 30 Hz. Numerical investigations representative of typical floor vibration levels experienced by machine tools demonstrate that the device isolates ground motion by up to 80%.

ABSTRACT High performance peripheral milling is one of the most common rough machining operations in modern production environments. Productivity of these operations, characterized by material removal rates (MRR) and machining times, is a function of several parameters: spindle speed, feed, axial and radial depths of cuts, tool path type, milling mode, and feed direction. Each of these variables affects the MRRs differently; the limiting case often resulting from the dynamic interactions between the cutting tool and the work piece - characterized by chatter vibrations. This paper proposes an integrated approach incorporating all of the significant factors affecting performance to formulate a mixed mode milling strategy for the case of profile-parallel peripheral milling of a rectangular part. Numerical investigations demonstrate an improvement in machining time of up to 28% over conventional approaches. Proposed methods can be used for selection of optimal cutting conditions, tool path type, and for dynamically modifying the tool path to maximize MRRs and minimize the machining times.

ABSTRACT This article describes a new visualization method for an illustrative visualization of physical values in immersive workspaces. Through the newly developed visualization pipeline, FEM results such as stress, temperature and resulting deformation, as well as the underlying constraints can be visualized in virtual and augmented reality (AR) applications. Special features are the use of 3D glyphs for mapping stress direction and gradient as well as data preparation and the resulting data format, which was especially developed for use with virtual reality (VR) systems. This article demonstrates the current state of VR developments, which were done at the Institute for Machine Tools and Production Processes, for improving the analysis of complex FE datasets, and gives an outlook to future research activities.

Activities for energy efficiency increase of machine tools and production systems can roughly be divided into direct efficiency increase on components level and efficiency increase by optimised interaction of the components on the respective higher system level. The paper is focused on system level. In the first part, influences on energy consumption in production are structured hierarchically. General aspects of

The increasing demand for machine tools and production systems to be more energy-efficient poses new challenges for machine developers. The paper discusses the general influence of lightweight design approaches on energy efficiency in machine tools and restrictions on the maximum mass reduction for structural components. As a central aspect different quantitative consequences of energy consumption aspects regarding lightweight design are

... Martina Katharina Wenger-Alack, Swiss Federal institute of technology (ETH), Switzerland ... Brigitte C. Morello, Mohamed Hedi Karay, Noureddine Zerhouni, FEMTO St institute, Université de franche comté, “New perspectives of maintenance systems: Towards s-maintenance" ...