STRUCTURAL HEALTH MONITORING AND LIFE PROGNOSIS OF AIRCRAFT COMPOSITE STRUCTURES

需求：越来越多的人有能力乘坐飞机旅行，无论是在加拿大境内还是境外，无论是出于休闲还是商务目的，航空运输都变得越来越容易。更重要的是，2012年加拿大航空运输系统的客运量超过1.2亿人次，比2011年增长3.6%。在2013年加拿大机场会议与展览会上，加拿大机场委员会公布了十多年来的第一份经济影响研究报告。2012年，加拿大航空运输业创造了349亿美元的经济足迹，提供了40.5万个就业岗位，个人收入超过170亿美元，联邦税收超过70亿美元。除此之外，还有更广泛的经济效益，例如支持偏远地区加拿大人的生计，促进北部和自然资源部门的经济发展，以及提高企业运营和效率。在未来十年，航空业预测客运量和货运量将以年均5%的速度增长，货运量的增长速度将略高于全球GDP增长速度。在航空运输方面，这意味着大约每16年航空运输量就会翻一番。因此，很明显，环境要求，如噪音影响、排放和安全，将在未来的运输飞机发展中发挥主导作用，成为运输新指标的驱动力。直接的绿色设计标准体现在：减少80%的氮氧化物排放，将每名乘客每公里感受到的飞机噪音和二氧化碳排放量减半，通过创新配置、减轻重量、改进制造工艺和产品、节能推进系统以及稳健可靠的基于状态的维护技术，将事故率降低80%。该提案概述了一项研究计划，旨在通过数学和计算模型以及实验方法的进步来提高复杂多学科工程系统的性能。主要目标是将新兴的数学模型和使能技术与新的设计和操作概念联系起来，以实现“更精简、更环保、更安全”的交通运输，重点是航空航天系统。研究了先进纤维增强聚合物飞机复合材料结构的健康管理问题。它基于三种SHM方法的评估和整合，包括超声波兰姆波、光纤传感器和基于振动的技术。提出了一种统一的结构健康监测方法。更具体地说，研究将集中在使用拟议的SHM方法（基于嵌入式光纤的Lamb波和振动）识别和检测复合材料结构损伤的信号处理技术和算法的发展，FBG传感器性能与基于Lamb波和振动的技术的比较，目的是开发统一的SHM方法。以及使用监测技术的发展，以预测复合材料结构的剩余使用寿命，使用粘合和/或嵌入式光纤传感器，其中复合材料结构包括带有开孔和粘合接头的板和带有铆钉的板。最后，为了使嵌入式系统具有自主性，还将探索使用压电换能器的能量收集技术。在基于状态的维护理念框架下的结构健康监测技术将允许减少机体维护操作的时间和成本。更具体地说，拟议的研究计划将降低飞机的运营成本，提高飞机的安全性。

THE NEED:Air transport is increasingly becoming more accessible to a greater number of people who can afford traveling by air, both inside and outside Canada, for leisure and business purposes. More to the point, Canada's air transportation system was used by more than 120 million passengers in 2012, an increase of 3.6% over 2011. At its Airports Canada 2013 Conference & Exhibition, the Canadian Airports Council unveiled its first economic impact study in more than a decade. Canada's air transportation industry had a $34.9-billion economic footprint in 2012, supported 405,000 jobs and personal income of more than $17 billion and federal taxation of more than $7 billion. This is in addition to broader economic benefits, such as supporting the livelihoods of Canadians in remote regions, economic development in the north and in the natural resources sector, and enhancing business operations and efficiency. Over the next decade, the sector forecasts that both passenger and freight traffic is expected to increase at an average of 5% p.a., with freight being expected to increase slightly more - both significantly above global GDP growth. In air transport terms, this implies a doubling of traffic about every 16 years. Thus, it is evident that environmental requirements, such as noise impact, emissions and safety, will play a dominant role in future transport aircraft development, becoming a driving force for new metrics in transportation. The direct greening design criteria are represented by 80% cut in NOx emissions, halving perceived aircraft noise and CO2 emissions per passenger-Km, and reducing accident rate by 80% through novel configurations, weight savings, improved manufacturing processes and products, energy efficient propulsion systems, and robust and reliable condition based maintenance techniques. PROPOSED PROGRAMThe proposal outlines a research program to improve the performance of complex multidisciplinary engineering systems through advances in mathematical and computational models, and experimental methods. The primary objective is to connect emerging mathematical models and enabling technologies with new designs and concepts of operations to achieve “Leaner, Greener and Safer” Transportation, with emphasis on aerospace systems. The research focuses on the Structural Health Management of advanced fiber reinforced polymer aircraft composite structures. It is based on the assessment and integration of three SHM methodologies including ultrasonic Lamb waves, fiber optic sensors and vibration-based techniques. A unified structural health monitoring approach is proposed. More specifically, the research will focus on the development of signal processing techniques and algorithms for identifying and detecting damages in composite structures using proposed SHM methodologies (Lamb waves and vibration based with embedded optical fiber), the comparison of FBG sensors performance with Lamb wave and vibration based techniques with the purpose of developing a unified SHM approach, and the development of usage monitoring techniques to predict the remaining useful life of composite structures using bonded and/or embedded fiber optic sensors where the composite structures include plates with open holes and bonded joints and plates with rivets. Finally, in order to make the embedded systems autonomous, energy harvesting techniques using piezoelectric transducers will also be explored.BENEFITSStructural Health Monitoring technology in the framework of a Condition based Maintenance philosophy will allow time and cost reduction of airframe maintenance operations. More specifically, the proposed research program will achieve reduced aircraft operating costs and improved aircraft safety and security.