Adaptronic Systems for Aerospace Applications (Adaptronische Systeme für Anwendungen in der Luftfahrt)

Boller, Christian

doi:10.1524/auto.2006.54.6.276

Cited by 3 publications

(2 citation statements)

References 28 publications

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“…Even though carbon nanostructure/TEM composites only allow for one-time expansion/actuation, the innovative combination of filler materials in an elastomer matrix and resulting binary set of material properties presents a plethora of research and industrial applications. Possible applications encompass fields such as structural health monitoring of aircraft [38] and ships [39], deformable elements for flight control surfaces [40], deformable mirror and antennae surfaces on spacecraft [41], strain sensing for roads and bridges [42], machinery vibration control systems [43], and biomedical applications including micropumps [44] and targeted drug delivery [45]. Elastic to plastic-like transformation allows for incorporation of sensing and actuation into a single coherent functional material thereby minimizing complexity and maximizing reliability.…”

Section: Discussionmentioning

confidence: 99%

Stimuli-responsive transformation in carbon nanotube/expanding microsphere–polymer composites

Loomis¹,

Xu²,

Panchapakesan³

2013

Nanotechnology

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Our work introduces a class of stimuli-responsive expanding polymer composites with ability to unidirectionally transform physical dimensions, elastic modulus, density, and electrical resistance. Carbon nanotubes and core-shell acrylic microspheres were dispersed in polydimethylsiloxane, resulting in composites that exhibit a binary set of material properties. Upon thermal or infrared stimuli, liquid cores encapsulated within the microspheres vaporize, expanding the surrounding shells and stretching the matrix. Microsphere expansion results in visible dimensional changes, regions of reduced polymeric chain mobility, nanotube tensioning, and overall elastic to plastic-like transformation of the composite. Here we show composite transformations including macroscopic volume expansion (>500%), density reduction (>80%), and elastic modulus increase (>675%). Additionally, conductive nanotubes allow for remote expansion monitoring and exhibit distinct loading-dependent electrical responses. With ability to pattern regions of tailorable expansion, strength, and electrical resistance into a single polymer skin, these composites present opportunities as structural and electrical building blocks in smart systems.

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Section: Discussionmentioning

confidence: 99%

Stimuli-responsive transformation in carbon nanotube/expanding microsphere–polymer composites

Loomis¹,

Xu²,

Panchapakesan³

2013

Nanotechnology

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“…An important class of interconnected systems consist of identical or near identical subsystems interacting with each other in a regular pattern. Some examples of such systems are smart materials used in vibro-acoustic control [1], flow pattern control [2], flexible primary mirrors of telescopes [3] and smart materials for aerospace applications [4] etc.…”

Section: Introductionmentioning

confidence: 99%

Simply structured controllers for parameter varying distributed systems

Chughtai¹,

Werner²

2010

Smart Mater. Struct.

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This paper presents a systematic approach to the synthesis of simply structured controllers for large scale parameter varying distributed systems. The design and optimization procedure consists of two loops. In an inner loop, an efficient LMI-based optimization algorithm is used to evaluate the closed-loop performance. The outer loop uses evolutionary operators to iteratively search for the parameters of a controller network that achieves the best performance.For the purpose of performance evaluation, new sufficient LMI conditions are presented to find the induced L 2 norm of such systems. The conservatism of the analysis is reduced by the use of parameter dependent Lyapunov functions and by taking bounds on the parameter variation rates into account. Since the control algorithms are implemented on digital computers, the results are presented for discrete time and discrete space systems. The problem posed in this form is infinite dimensional, a gridding algorithm is also proposed to convert it into a finite dimensional problem.The approach is illustrated with two applications: active vibration control of a cantilever, and position control of a seismic cable. These examples illustrate that the performance analysis condition presented here is less conservative than previously presented LMI conditions. It is also demonstrated that the approach can be used to systematically design simply structured low-order controllers, while satisfying all performance requirements.

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A process chain for integrating piezoelectric transducers into aluminum die castings to generate smart lightweight structures

et al. 2017

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The application of piezoelectric transducers to structural body parts of machines or vehicles enables the combination of passive mechanical components with sensor and actuator functions in one single structure. This approach has high potential for smart lightweight constructions. To obtain the highest yield, the piezoelectric transducers need to be integrated into the flux of forces (load path) of load bearing structures. Application in a downstream process reduces yield and process efficiency during manufacturing and operation, due to the necessity of a subsequent process step of sensor/actuator application. The die casting process offers the possibility for integration of piezoelectric transducers into metal structures. Particularly favorable are aluminum castings due to their high quality and feasibility for high unit production at low cost. Such molded aluminum parts with integrated piezoelectric transducers enable functions like active vibration damping, structural health monitoring or energy harvesting resulting in significant possibilities of weight reduction, which is an increasingly important driving force of automotive and aerospace industry due to increasingly stringent environmental protection laws. In the scope of those developments, this paper focuses on the entire process chain enabling the generation of lightweight metal structures with sensor and actuator function, starting from the manufacturing of piezoelectric modules over electrical and mechanical bonding to the integration of such modules into aluminum (Al) matrices by die casting. To achieve this challenging goal, piezoceramic sensors/actuator modules, so-called LTCC/PZT modules (LPM) were developed, since ceramic based piezoelectric modules are more likely to withstand the thermal stress of about 700 °C introduced by the casting process. The modules are made of low temperature cofired ceramic (LTCC) tapes with an embedded lead zirconate titanate (PZT) plate and are manufactured in multilayer technique. For joining conducting copper (Cu) wires with the electrode structure of the LPM, a novel laser drop on demand wire bonding method (LDB) is applied, which is based on the melting of a spherical CuSn12 braze preform with a liquidus temperature Tliquid of 989.9 °C providing sufficient thermal stability for a subsequent casting process

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Adaptronic Systems for Aerospace Applications (Adaptronische Systeme für Anwendungen in der Luftfahrt)

Cited by 3 publications

References 28 publications

Stimuli-responsive transformation in carbon nanotube/expanding microsphere–polymer composites

Stimuli-responsive transformation in carbon nanotube/expanding microsphere–polymer composites

Simply structured controllers for parameter varying distributed systems

A process chain for integrating piezoelectric transducers into aluminum die castings to generate smart lightweight structures

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