Leveraging technological knowledge to drive one's own technological and business decisions requires extensive but carefully planned networking. Furthermore, to efficiently assess huge amounts of available informat...
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Leveraging technological knowledge to drive one's own technological and business decisions requires extensive but carefully planned networking. Furthermore, to efficiently assess huge amounts of available information for such decisions, automated methods for data analysis are gaining importance. To research effective software support systems in technology intelligence, we established a platform for technology information research, management, automation and collaboration. This platform is used to research method combinations and partnership models. In this paper, we present the system architecture and cooperation structure, and a case study of the platform's use. We elaborate design and methodology decisions, give a general overview of the technologies employed, and name future research activities.
Shape Memory Alloys are well known and established in medical engineering. In recent years their importance considering industrial applications also increased. Especially the high specific work load of the material an...
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ISBN:
(纸本)9783800735372
Shape Memory Alloys are well known and established in medical engineering. In recent years their importance considering industrial applications also increased. Especially the high specific work load of the material and the simple working principle of SMA actuator systems possess them to be a suitable alternative to conventional drives. The benefits of the technology directly address the main demands on actuator technologies like miniaturisation, lightweight design and costs. Further SMAs can be an alternative to substitute rare earth metals. In the paper we present the status quo of SMA technology. The shape memory effect as a basis for understanding the working principles of such actuators is described. Beyond that mechanical design rules are explained. That covers the three possible actuating principles constant- and spring loaded and antagonistically arranged SMA actuators. Besides simple switching applications, there are rather complex controlled SMA actuators using external sensors or inherent resistance feedback. Control principles for both approaches are presented. To show potentials but also the limitations of SMA actuators, applications from different markets with different demands are described. They specify the certain challenges which have to be overcome before a comprehensive market acceptance of SMAs in industrial applications can be expected. The estimated developments in the future will be discussed further.
The air conditioning unit (AC unit) is one of the major sound sources for exterior and interior noise of a railway vehicle. The design of such devices is a compromise between main functions like efficiency, fluid mech...
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In the majority of cases, aluminium matrix composites (AMCs) consist of a relatively ductile matrix and hard ceramic particles embedded therein. In addition to an increased tool wear, machining of these materials invo...
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ISBN:
(纸本)9780956679024
In the majority of cases, aluminium matrix composites (AMCs) consist of a relatively ductile matrix and hard ceramic particles embedded therein. In addition to an increased tool wear, machining of these materials involves surface imperfections like voids and scaling. An approach to reduce the generation of suchlike imperfections is a modification of the cutting edge geometry. Turning tests have shown that smooth surfaces can be generated by using natural diamond tipped tools with a very small clearance angle of approximately 0.5 and a minor feed of 0.05 mm.
This contribution presents current results on ultra-precision grinding and polishing of silicon carbide for mirrors, which has been investigated within the research project MirrorFab. The effects of different grinding...
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ISBN:
(纸本)9780956679024
This contribution presents current results on ultra-precision grinding and polishing of silicon carbide for mirrors, which has been investigated within the research project MirrorFab. The effects of different grinding wheels and process parameters on the shape accuracy, surface roughness and the grinding forces are discussed. It turned out, that surface qualities in the range of 10 nm Rms can be achieved with appropriate parameters. In polishing, the focus is set to the investigation of the effects of various polishing pads and slurries on the material removal rate and surface roughness. Two combinations (polishing pad and slurry) are recommended, one features a high material removal rate for fast removal of grinding marks and the other one a low surface roughness for final smoothing. The presented results enable a systematic adaption of the grinding and polishing processes to the varying requirements in manufacturing silicon carbide mirrors.
In the described investigations, nano-impact tests were conducted on PVD film surfaces previously subjected to micro-blasting at different pressures for constant duration. Micro-blasting improves the film mechanical p...
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ISBN:
(纸本)9789608810433
In the described investigations, nano-impact tests were conducted on PVD film surfaces previously subjected to micro-blasting at different pressures for constant duration. Micro-blasting improves the film mechanical properties due to the induced residual compressive stresses into the coating structure. The film mechanical properties as well as the ratio of the film yield to rupture stress (SY/SM) grow up to a certain micro-blasting pressure. The augmentation of SY/SM ratio increases simultaneously the film brittleness. For analyzing the effect of the SY/SM ratio on the film brittleness, a multi-layer 3D-FEM model simulating the nano-impact test was developed, employing the LS-DYNA software package. The FEM calculated results converge sufficiently with the attained experimental ones. Based on these results, the film's failure initiation and evolution can be predicted depending on the SY/SM ratio of the individual film layers.
Simulation is established within the development process in order to validate technical systems at an early stage. Nonetheless, the required level of detail and the late availability of simulation models limit an econ...
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Simulation is established within the development process in order to validate technical systems at an early stage. Nonetheless, the required level of detail and the late availability of simulation models limit an economic application. This paper describes a novel approach for an interactive and mechatronic design of technical alternatives at early stages of development and in this regard the evaluation with physically based simulation models.
Currently grinding is commonly used as the finishing operation to manufacture seal mating surfaces and bearing surfaces, especially in the automotive industry. It would lead to more resource-efficient production if th...
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Currently grinding is commonly used as the finishing operation to manufacture seal mating surfaces and bearing surfaces, especially in the automotive industry. It would lead to more resource-efficient production if the cost- and energy-intensive grinding process could be replaced by machining with geometrically defined cutting edges, such as hard turning [1] , [2] . However, turning operations usually cause a twist structure on the surface, which can convey lubricants like a pump. Several methods exist to overcome this problem, for example, tangential turning, rotation turning and turn broaching, etc. Due to the high costs of tools and special machines required by these methods, the industrial application is still limited. This paper describes a more efficient approach by applying a modified feed kinematic. When using this approach, hard turning produces twist-free surfaces. The results of the latest twist test methods have confirmed that the surfaces are free of twist, hence free of conveying effect of lubricant and that they are suitable for application in manufacturing of seal mating surfaces and bearing surfaces. Furthermore, this method requires only minimal investment in any turning machine.
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