65 research outputs found

    Manufacturing Prosperity: A Bold Strategy for National Wealth and Security

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    Offshore production in advanced manufacturing has reached a critical point in which the strategy of “invent here, manufacture there” has become “invent there, manufacture there.” The United States must take bold steps to arrest this development and take advantage of transformational technologies to rebuild domestic manufacturing prowess for national wealth and security. These bold steps require a central national focal point with a comprehensive strategy, and significant and sustained public and private investments: 1. Invest in translational research and manufacturing innovation 2. Encourage domestic pilot production and scale-up 3. Empower small and medium-sized manufacturers to deploy advanced technologies 4. Grow domestic engineering and technical talentNational Science Foundation, Grant No. 1552534https://deepblue.lib.umich.edu/bitstream/2027.42/145156/1/ManufacturingProsperityReport_digital_reduced.pdfDescription of ManufacturingProsperityReport_digital_reduced.pdf : Repor

    A knowledge-based system for nondestructive testing of polymeric composite components

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    This paper presents a formalization of the knowledge domain of nondestructive quality control of polymeric composite components. The formalization scheme presented in this paper has been implemented in a prototype knowledge-based expert system (KBES), called NICC for nondestructive inspection of composite components, to help in the quality assurance of these parts. Geometric and bonding characteristics of individual and assembled components are taken into account, as opposed to the better understood evaluation of well-behaved test specimens. The use of nondestructive techniques in the inspection of plastic and polymeric composites is fairly recent and hence, the knowledge required to develop a KBES is still very scattered and not yet fully covered in the literature. This study demonstrates both the feasibility of compiling and representing this knowledge domain and the possibility of translating it into an efficient automated tool capable of giving reliable expert-like advice at low cost. The reasoning process is divided into three stages. In the first stage, a polymetric composite component is completely defined according to features that are relevant for nondestructive inspection. In the second stage, all the discontinuities that may be present in the component are determined. Finally, in the third stage, appropriate nondestructive testing procedures are identified to detect each of the possible discontinuities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45924/1/164_2005_Article_BF01607873.pd

    An Adaptive Structures Electro-mechanical Device for Dynamic Flow Control Applications

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76818/1/AIAA-2004-1815-582.pd

    Active flow control using high frequency compliant structures

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77267/1/AIAA-2001-4144-449.pd

    Design of Compliant Mechanisms: Applications to MEMS

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    Compliant mechanisms are single-piece flexible structures that deliver the desired motion by undergoing elastic deformation as opposed to jointed rigid body motions of conventional mechanisms. Compliance in design leads to jointless, no-assembly (Fig. 1), monolithic mechanical devices and is particularly suited for applications with small range of motions. The compliant windshield wiper shown in Fig. 1 illustrates this paradigm of no-assembly. Conventional flexural mechanisms employ flexural joints that connect relatively rigid links as depicted in Fig. 2. Reduced fatigue life, high stress concentration and difficulty in fabrication are some of the drawbacks of flexural joints. Our focus is on designing compliant mechanisms with distributed compliance which employs flexural links (see Fig. 3) and have no joints (neither pin nor flexural joints) for improved reliability, performance, and ease of manufacture. Distributed compliant mechanisms derive their flexibility due to topology and shape of the material continuum rather than concentrated flexion at few regions. This paper focuses on the unique methodology employed to design jointless mechanisms with distributed compliance. The paper also illustrates a compliant stroke amplification mechanism that was recently designed, fabricated and tested for MEMS application.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44061/1/10470_2004_Article_353448.pd

    Evaluation of the Hinge Moment and Normal Force Aerodynamic Loads from a Seamless Adaptive Compliant Trailing Edge Flap in Flight

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    A seamless adaptive compliant trailing edge (ACTE) flap was demonstrated in flight on a Gulfstream III aircraft at the NASA Armstrong Flight Research Center. The trailing edge flap was deflected between minus 2 deg up and plus 30 deg down in flight. The safety-of-flight parameters for the ACTE flap experiment require that flap-to-wing interface loads be sensed and monitored in real time to ensure that the structural load limits of the wing are not exceeded. The attachment fittings connecting the flap to the aircraft wing rear spar were instrumented with strain gages and calibrated using known loads for measuring hinge moment and normal force loads in flight. The safety-of-flight parameters for the ACTE flap experiment require that flap-to-wing interface loads be sensed and monitored in real time to ensure that the structural load limits of the wing are not exceeded. The attachment fittings connecting the flap to the aircraft wing rear spar were instrumented with strain gages and calibrated using known loads for measuring hinge moment and normal force loads in flight. The interface hardware instrumentation layout and load calibration are discussed. Twenty-one applied calibration test load cases were developed for each individual fitting. The 2-sigma residual errors for the hinge moment was calculated to be 2.4 percent, and for normal force was calculated to be 7.3 percent. The hinge moment and normal force generated by the ACTE flap with a hinge point located at 26-percent wing chord were measured during steady state and symmetric pitch maneuvers. The loads predicted from analysis were compared to the loads observed in flight. The hinge moment loads showed good agreement with the flight loads while the normal force loads calculated from analysis were over-predicted by approximately 20 percent. Normal force and hinge moment loads calculated from the pressure sensors located on the ACTE showed good agreement with the loads calculated from the installed strain gages

    Approach for Structurally Clearing an Adaptive Compliant Trailing Edge Flap for Flight

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    The Adaptive Compliant Trailing Edge (ACTE) flap was flown on the National Aeronautics and Space Administration (NASA) Gulfstream GIII testbed at the NASA Armstrong Flight Research Center. This smoothly curving flap replaced the existing Fowler flaps creating a seamless control surface. This compliant structure, developed by FlexSys Inc. in partnership with the Air Force Research Laboratory, supported NASA objectives for airframe structural noise reduction, aerodynamic efficiency, and wing weight reduction through gust load alleviation. A thorough structures airworthiness approach was developed to move this project safely to flight. A combination of industry and NASA standard practice require various structural analyses, ground testing, and health monitoring techniques for showing an airworthy structure. This paper provides an overview of compliant structures design, the structural ground testing leading up to flight, and the flight envelope expansion and monitoring strategy. Flight data will be presented, and lessons learned along the way will be highlighted

    Active Flow Control Using High-Frequency Compliant Structures

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76783/1/AIAA-111-490.pd
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