Interior noise and sonic fatigue are important issues in the development and design of advanced subsonic and supersonic aircraft. Conventional aircraft typically employ passive treatments, such as constrained layer damping and acoustic absorption materials, to reduce the structural response and resulting acoustic levels in the aircraft interior. These techniques require signi cant addition of m...

Two levels of fidelity are used for minimum weight design of a composite bladestiffened panel subject to crack propagation constraints. The low fidelity approach makes use of an equivalent strain constraint calculated by a closed form solution for the stress intensity factor. The high fidelity approach uses the stress intensity factor directly as the constraint and computes it from the stress d...

In this study, physical, mechanical, and flammability properties of coconut fiber reinforced polypropylene (PP) composite panels were evaluated. Four levels of the coir fiber content (40, 50, 60, and 70 % based on the composition by weight) were mixed with the PP powder and a coupling agent, 3 wt % maleic anhydride grafted PP (MAPP) powder. The water resistance and the internal bond strength of...

This paper presents an alternative concept for the production of a lightweight vehicle chassis, using preformed flat panels assembled into a primary structure by the simple processes of CNC routing, folding and adhesive bonding. Minimal tooling and a fully CAD integrated, software driven process provide considerable advantages in prototype development and series production: modifications can be...

We propose in this article a Composite Logistic Regression (CLR) approach for ordinal panel data regression. The new method transforms the original ordinal regression problem into a number of binary ones. Thereafter, the method of conditional logistic regression (Chamberlain, 1984; Wooldridge, 2001; Hsiao, 2003) can be directly applied. As a result, the new method allows the unobserved subject ...

For modern aircraft, wind turbines, and other aerospace structures composites are replacing metal components. These aerospace structures will be designed and expected to perform well for many years ahead. Therefore, structural health monitoring (SHM) systems are being designed to monitor these structures to improve maintenance, repairing or replacing composites components when the need arises. ...

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Primary care practices are turning toward team-based strategies such as panel management, in which nonclinicians address routine preventive and chronic disease care tasks for a group of patients. No known validated instruments have been published for measuring panel management implementation. The authors developed the 12-item Panel Management Questionnaire (PMQ) measuring 4 domains. Data were a...