The need for even greater efficiency in handling resources is coming to be seen as a public duty in politics, commerce and research. At the same time this raises the question of what options are open to companies in t...
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The need for even greater efficiency in handling resources is coming to be seen as a public duty in politics, commerce and research. At the same time this raises the question of what options are open to companies in the manufacturing industries - and, in particular, the OEMs and suppliers to the automotive industry - for reducing costs as well as deployment of resources and emissions. In addition to illustrating and analysing the relevance of this topic as far as formingtechnology is concerned, the following article discusses a selection of approaches that are being adopted in the fraunhofer Institute for machinetools and formingtechnology with a view to reducing the consumption of resources, particularly in the bodywork parts production sector.
Tests were undertaken using micro-EDM drilling with Tungsten Carbide Electrodes and ZrO2 ceramic. A starting layer, in literature often referred to as 'assisting electrode' was used to set up a closed electric...
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In the development of modern machinetools for the automotive industry, higher productivity, higher metal removal rates and lower machining tolerances are increasingly calling for allowance to be made for misalignment...
In the development of modern machinetools for the automotive industry, higher productivity, higher metal removal rates and lower machining tolerances are increasingly calling for allowance to be made for misalignments due to thermal factors. Improving the accuracy of thermal simulation was the subject of a project conducted at the fraunhofer Institute for machinetools and formingtechnology (iwu).
Finite element analysis (FEA) is a wide-spread method for studying the mechanical properties of structures. Finite element models (FE models) are being increasingly used in medical technology and biomechanics for calc...
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ISBN:
(纸本)9781615677368
Finite element analysis (FEA) is a wide-spread method for studying the mechanical properties of structures. Finite element models (FE models) are being increasingly used in medical technology and biomechanics for calculating dynamic problems with bones and artificial limbs. X-ray computer tomography data is used to create models that supply very precise information on morphology and tissue density. This article describes how experimental measurements of the dynamic behavior of the human hip bone can be obtained to verify different FE modeling approaches. Several mapping functions known from the literature will be used for material parameters in the FE models and the findings are compared. This paper specially focuses on the measuring method streamlined for fresh preparations using a 3-D laser vibrometer for the first time to capture oscillations threedimensionally.
The fraunhofer Institute for machinetools and formingtechnology has set itself the challenge of characterising the material behaviour of very recently developed sheet metal materials. To this end, an integrated conc...
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ISBN:
(纸本)9788957081525
The fraunhofer Institute for machinetools and formingtechnology has set itself the challenge of characterising the material behaviour of very recently developed sheet metal materials. To this end, an integrated concept for the determination of material characteristics has been established. This consists in further developing well-known methods based on innovative characterisation concepts for describing phenomena such as springback, anistropy and the Bauschinger Effect. Using this approach, information relating to the interaction of sheet material, lubrication and forming tool can be derived.
During the hot pressing of glass (e.g. precision glass moulding, hot embossing) form deviations between the tool geometry and the manufactured glass formed part arise. Reasons for it are different thermal expansion be...
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ISBN:
(纸本)9780955308253
During the hot pressing of glass (e.g. precision glass moulding, hot embossing) form deviations between the tool geometry and the manufactured glass formed part arise. Reasons for it are different thermal expansion behaviour of the materials and technological parameters. The form deviation resulting from these measured variables gains more and more significance with a rising scale of miniaturization. For the hot embossing of flat glass substrates with several cavities (e.g. micro lens arrays, microfluidic components) at the fraunhoferiwu a method was developed, in order to determine the total form deviation with the help of uncomplex shaped dies experimentally. The obtained accuracy is sufficient in order to correct ordinary optical geometries, like spherical cavities, or the pitch of V-grooves and channel structures respectively. For different tool materials and inorganic glasses according to this method correction factors were determined to compensate the process inherent form deviation. In this way complex iteration steps in the manufacturing of the tool moulds can be minimized.
The need for high-aspect ratio micro structures in hard to machine materials is constantly growing. Electro-Physical machining processes such as EDM offer distinct advantages to conventional machining technologies suc...
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ISBN:
(纸本)9780955308253
The need for high-aspect ratio micro structures in hard to machine materials is constantly growing. Electro-Physical machining processes such as EDM offer distinct advantages to conventional machining technologies such as independence of material hardness, but are difficult to control for high-precision and micro applications [1]. It is therefore of great importance to provide means of fast and stable machining in Micro-EDM, e.g. optimize process and discharge efficiency. In this study, a novel approach to characterize erosion efficiency in Micro-EDM is made by recording erosion current and voltage with high resolution and long recording time. The paper presents the objectives of pulse shape classification for micro-EDM and lines out how a rating of erosion efficiency can be realized by studying the number and sequence of current and voltage of the erosion pulses. Thus, process analysis can be improved and optimized parameters can be adopted to the process state, eventually leading to an on-line process control.
As the compression behaviour has been identified as one of the key properties of cellular materials, a draft for a standard for the compression test for cellular metals was developed and discussed within the German/Au...
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ISBN:
(纸本)9781932078282
As the compression behaviour has been identified as one of the key properties of cellular materials, a draft for a standard for the compression test for cellular metals was developed and discussed within the German/Austrian working group on cellular materials. The test and evaluation procedure outlined in the present paper pays special attention to problems linked with the inhomogeneity of most cellular materials, the structure-dependent stiffness and variations in the shape and length of the plateau regime in the stress-strain curve. The paper provides experimental support for the decision on the test and evaluation procedure and examples for the application of the draft on several kinds of cellular metals.
This paper reviews current developments in mechatronic systems for metal cutting and formingmachinetools. The integration of mechatronic modules to the machine tool and their interaction with manufacturing processes...
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This paper reviews current developments in mechatronic systems for metal cutting and formingmachinetools. The integration of mechatronic modules to the machine tool and their interaction with manufacturing processes are presented. Sample mechatronic components for precision positioning and compensation of static, dynamic and thermal errors are presented as examples. The effect of modular integration of mechatronic system on the reconfigurability and reliability of the machinetools is discussed along with intervention strategies during machine tool operation. The performance and functionality aspects are discussed through active and passive intervention methods. A special emphasis was placed on active and passive damping of vibrations through piezo, magnetic and electro-hydraulic actuators. The modular integration of mechatronic components to the machine tool structure, electronic unit and CNC software system is presented. The paper concludes with the current research challenges required to expand the application of mechatronics in machinetools and manufacturing systems.
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