The major objective of this book was to identify issues related to the introduction of new materials and the effects that advanced materials will have on the durability and technical risk of future civil aircraft throughout their service life. The committee investigated the new materials and structural concepts that are likely to be incorporated into next generation commercial aircraft and the factors influencing application decisions. Based on these predictions, the committee attempted to identify the design, characterization, monitoring, and maintenance issues that are critical for the introduction of advanced materials and structural concepts into future aircraft.
Advanced polymer matrix composites (PMC) have many advantages such as light weight and high specific strength that make them useful for many aerospace applications. Enormous uncertainty exists, however, in predicting long-term changes in properties of PMCs under extreme environmental conditions, which has limited their use. To help address this issue, the Department of Defense requested a study from the NRC to identify the barriers and limitations to the use of PMCs in extreme environments. The study was to focus on issues surrounding methodologies for predicting long-term performance. This report provides a review of the challenges facing application of PMCs in extreme environments, the current understanding of PMC properties and behavior, an analysis of the importance of data in developing effective models, and recommendations for improving long-term predictive methodologies.
This book is the first of two volumes providing comprehensive coverage of the fundamental knowledge and technology of composite materials. It covers a variety of design, fabrication and characterization methods as applied to composite materials, particularly focusing on the fiber-reinforcement mechanism and related examples. It is ideal for graduate students, researchers, and professionals in the fields of Materials Science and Engineering, and Mechanical Engineering.
In January-February 2005, the National Academies Committee on Counterterrorism Challenges for Russia and the United States and the Russian Academy of Sciences Standing Committee on Counterterrorism held a workshop on urban terrorism in Washington, D.C. Prior to the workshop, three working groups convened to focus on the topics of energy systems vulnerabilities, transportation systems vulnerabilities, and cyberterrorism issues. The working groups met with local experts and first responders, prepared reports, and presented their findings at the workshop. Other workshop papers focused on various organizations' integrated response to acts of urban terrorism, recent acts of terrorism, radiological terrorism, biological terrorism, cyberterrorism, and the roots of terrorism.
Structural Health Monitoring (SHM) in Aerospace Structures provides readers with the spectacular progress that has taken place over the last twenty years with respect to the area of Structural Health Monitoring (SHM). The widespread adoption of SHM could both significantly improve safety and reduce maintenance and repair expenses that are estimated to be about a quarter of an aircraft fleet's operating costs. The SHM field encompasses transdisciplinary areas, including smart materials, sensors and actuators, damage diagnosis and prognosis, signal and image processing algorithms, wireless intelligent sensing, data fusion, and energy harvesting. This book focuses on how SHM techniques are applied to aircraft structures with particular emphasis on composite materials, and is divided into four main parts. Part One provides an overview of SHM technologies for damage detection, diagnosis, and prognosis in aerospace structures. Part Two moves on to analyze smart materials for SHM in aerospace structures, such as piezoelectric materials, optical fibers, and flexoelectricity. In addition, this also includes two vibration-based energy harvesting techniques for powering wireless sensors based on piezoelectric electromechanical coupling and diamagnetic levitation. Part Three explores innovative SHM technologies for damage diagnosis in aerospace structures. Chapters within this section include sparse array imaging techniques and phase array techniques for damage detection. The final section of the volume details innovative SHM technologies for damage prognosis in aerospace structures. This book serves as a key reference for researchers working within this industry, academic, and government research agencies developing new systems for the SHM of aerospace structures and materials scientists. - Provides key information on the potential of SHM in reducing maintenance and repair costs - Analyzes current SHM technologies and sensing systems, highlighting the innovation in each area - Encompasses chapters on smart materials such as electroactive polymers and optical fibers
