Purpose - The increasing interest in engineering structures made from multiple materials has led to corresponding interest in technologies, which can fabricate multi-material parts. The purpose of this paper is to fur...
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Purpose - The increasing interest in engineering structures made from multiple materials has led to corresponding interest in technologies, which can fabricate multi-material parts. The purpose of this paper is to further explore of the multi-material fabrication capabilities of ultrasonic consolidation (UC). Design/methodology/approach - Various combinations of materials including titanium, silver, tantalum, aluminum, molybdenum, stainless steel, nickel, copper, and MetPreg (R) were ultrasonically consolidated. Some of the materials were found to be effective as an intermediate layer between difficult to join materials. Elemental boron particles were added in situ between selected materials to modify the bonding characteristics. Microstructures of deposits were studied to evaluate bond quality. Findings - Results show evidence of good bonding between many combinations of materials, thus illustrating increasing potential for multi-material fabrication using UC. Originality/value - multi-material fabrication capabilities using UC and other additive manufacturing processes is a critical step towards the realization of engineering designs which make use of functionalmaterial combinations and optimization.
Piezoelectric poly(vinylidene fluoride –trifluoroethylene) copolymer is embedded as a functionalmaterial in a table-tennis racquet. Together with the developed electronics, this piezoelectric sensor is able to monit...
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Piezoelectric poly(vinylidene fluoride –trifluoroethylene) copolymer is embedded as a functionalmaterial in a table-tennis racquet. Together with the developed electronics, this piezoelectric sensor is able to monitor the position where the ball contacts the *** order to build up the device, conventional circuit boards with adapted electrode structures are used as substrates for the piezoelectric table-tennis racquet. This leads to challenges because such substrates are usually not flat in the micrometer range as well as the heights of copper electrodes cause irregularities in the final surface topology. Here, the adaptation of the circuit boards, the processing and polarization of the piezoelectric polymer layer, the designed electronics for signal detection and the properties of the table tennis racquet are discussed.
The demand in industry for lighter materials has facilitated the approval of composites for construction in many industries. This acceptance continues to grow and to find new applications. Now with even higher demands...
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The demand in industry for lighter materials has facilitated the approval of composites for construction in many industries. This acceptance continues to grow and to find new applications. Now with even higher demands in performance, industry is turning to more advanced materialsystems. These systems are using materials such as carbon composites. Unfortunately, carbon composites are not compatible with most metals and composite materials because of their low coefficient of thermal expansion. Carbon foam, though, is very compatible with carbon composites and offers solutions for integration for these advanced materialsystems. The market for finished carbon composites continues to grow and is projected by many to be close to $10.0 billion by 2010. The growth is a reflection of the increasing demand for this advanced material. The ability to utilize this novel material in new structures will be critically important and is especially complicated when there is a required transition to a metal or other non-carbon material. This paper will show how carbon foam can be integrated with carbon composites and other materials to provide an advanced material solution for the designers of the future.
Photonic switching systems in wavelength-division-multiplexed (WDM) networks are discussed. By employing collinear acoustooptic (AO) devices as wavelength selective functional devices. the system structure can be simp...
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Photonic switching systems in wavelength-division-multiplexed (WDM) networks are discussed. By employing collinear acoustooptic (AO) devices as wavelength selective functional devices. the system structure can be simplified with flexibility in wavelength assignment. As the AO devices. collinear AO wavelength separators and switches consisting of an optical directional coupler are investigated in integrated structures. Integrated optic devices such as WDM demultiplexers/multiplexers, wave length-selective matrix-switches. and routers for delay time selection in buffer memories are described. Wavelength selective characteristics are theoretically estimated for a material combination of TiO2/Ta2O5/proton-exchanged layers on LiNbO3 Substrates. The switching capacity in the switching system consisting of AO devices is evaluated. Issues for employing AID switching devices in WDM networks are also discussed.
Two key words for mechanical engineering in the future are Micro and Intelligence. It is weIl known that the leadership in the intelligence technology is a marter of vital importance for the future status of industria...
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ISBN:
(数字)9789401703710
ISBN:
(纸本)9781402010613;9789048161928
Two key words for mechanical engineering in the future are Micro and Intelligence. It is weIl known that the leadership in the intelligence technology is a marter of vital importance for the future status of industrial society, and thus national research projects for intelligent materials, structures and machines have started not only in advanced countries, but also in developing countries. materials and structures which have self-sensing, diagnosis and actuating systems, are called intelligent or smart, and are of growing research interest in the world. In this situation, the IUT AM symposium on Dynamics 0/ Advanced materials and Smart structures was a timely one. Smart materials and structures are those equipped with sensors and actuators to achieve their designed performance in achanging environment. They have complex structural properties and mechanical responses. Many engineering problems, such as interface and edge phenomena, mechanical and electro-magnetic interaction/coupling and sensing, actuating and control techniques, arise in the development ofintelligent structures. Due to the multi-disciplinary nature ofthese problems, all ofthe classical sciences and technologies, such as applied mathematics, material science, solid and fluid mechanics, control techniques and others must be assembled and used to solve them. iutam weIl understands the importance ofthis emerging technology. An iutamsymposium on Smart structures and Structronic systems (Chaired by U.
Today, multi-functionalmaterials such as piezoelectric/ferroelectric ceramics, magneto-strictive and shape memory alloys are gaining increasing applications as sensors, actuators or smart composite materials systems ...
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ISBN:
(数字)9789048198870
ISBN:
(纸本)9789048198863;9789400734333
Today, multi-functionalmaterials such as piezoelectric/ferroelectric ceramics, magneto-strictive and shape memory alloys are gaining increasing applications as sensors, actuators or smart composite materials systems for emerging high tech areas. The stable performance and reliability of these smart components under complex service loads is of paramount practical importance. However, most multi-functionalmaterials suffer from various mechanical and/or electro-magnetical degra-dation mechanisms as fatigue, damage and fracture. Therefore, this exciting topic has become a challenge to intensive international research, provoking the interdisciplinary approach between solid mechanics, materials science and physics. This book summarizes the outcome of the above mentioned iutam-symposium, assembling contributions by leading scientists in this area.
Particularly, the following topics have been addressed: (1) Development of computational methods for coupled electromechanical field analysis, especially extended, adaptive and multi-level finite elements. (2) Constitutive modeling of non-linear smart material behavior with coupled electric, magnetic, thermal and mechanical fields, primarily based on micro-mechanical models. (3) Investigations of fracture and fatigue in piezoelectric and ferroelectric ceramics by means of process zone modeling, phase field simulation and configurational mechanics. (4) Reliability and durability of sensors and actuators under in service loading by alternating mechanical, electrical and thermal fields. (5) Experimental methods to measure fracture strength and to investigate fatigue crack growth in ferroelectric materials under electromechanical loading. (6) New ferroelectric materials, compounds and composites with enhanced strain capabilities.
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