摘要
目前飞机等结构的安全主要通过疲劳及损伤容限设计来保证,但设计阶段采用的载荷谱与结构服役期间所承受的实际载荷谱存在差异,设计阶段无法准确预测结构的实际使用寿命。为保障结构服役期间的安全,设计基于三维断裂理论的结构损伤在线监测系统。系统通过传感器实时监测结构关键点处的载荷谱,并基于三维断裂力学理论,计算结构在载荷谱作用下损伤的扩展。系统采用现场总线和以太网两种通信方式,当数据传输量小、实时性要求较高时,可采用现场总线通信,当数据传输量大、实时性要求不高时,可采用以太网通信。针对大型结构需要多点监测的需求,提出基于现场总线和以太网构建分布式监测系统的两种方案。通过对标准试件在常幅载荷作用下疲劳裂纹的扩展进行监测,演示系统的工作原理和技术可行性。
At present,the safety of structures,such as aeroplane et al,is mainly achieved through fatigue design and damage tolerance design.But the service life is hard to predict precisely in the design stage because of the difference between the loading spectrum in design and the loading spectrum in service.For the safety of the structures in service,the three-dimensional fracture theory based on-line damage monitoring system is developed.The loading spectrum,real-time monitored by sensors,is analyzed with three-dimensional fracture theory and the damage propagation is computed.Field bus and Ethernet are used in the system.The field bus is suitable for less data transmission and high real-time requirement,while Ethernet is suitable for more data transmission and relatively low real-time requirement.According to the requirement of multipoint monitoring for large scale structures,two distributed monitoring systems respectively based on field bus and Ethernet are proposed.The working principle and technology feasibility are verified by monitoring the fatigue crack propagation of standard specimens under constant amplitude loading.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2011年第10期31-37,共7页
Journal of Mechanical Engineering
基金
国家自然科学基金(10732040)
航空科学基金(2007ZA502011)资助项目
关键词
在线监测系统
三维断裂理论
疲劳裂纹扩展
以太网
现场总线
On-line monitoring system Three dimensional fracture theory Fatigue crack propagation Ethernet Field bus
