Compensation of Temperature Effects on Guided Wave Based Structural Health Monitoring Systems

Temperature effect correction based on waveguide structure health monitoring system Introduction In recent years, structural soundness evaluation based on the structure of ultrasonic piezoelectric sensor capable of radiating and recording Lamb wave is rapidly developing. Aerospace manufacturers can access complete ready-made monitoring solutions, including embedded sensor networks, acquisition units, and required software. A pre-established sensor network can be placed in the composite structure to open a portal to permanent health monitoring and residual life assessment.

Because dynamic properties (frequency, mode shape, attenuation) are closely related to structural parameters such as stiffness and mass, dynamic based methods are widely used for structural health monitoring and damage identification. Currently, most studies focus on the impact of damage on dynamic performance without considering the temperature effects. However, if the influence is not properly taken into account and not removed, the result of identifying the damage is unreliable. Farat et al. We will introduce monitoring results of Alamosa Canyon Bridge. They discovered that the initial natural frequency of this structure varies by about 5% within 24 hours. Askegaard and Mossing discovered that the frequency of a pedestrian bridge with three spans is 10% of the year. Wahab and de Roeck observed 4% to 5% of natural frequency fluctuation of prestressed concrete bridge in spring and winter by dynamic test.

Distortion during use is called "intelligent structure health monitoring system". The term intelligent material and structure is widely used to describe the unique combination of materials and structural engineering using optical fiber sensors and drive control technology. A smart structure consists of materials that allow you to continually monitor its own mechanical and physical properties, evaluate damage, and warn of imminent structural integrity defects. This design concept improves safety and economic problems with regard to weight saving and over-design of long-term structure. Figure 1 shows a schematic diagram of the structural possibilities resulting from the convergence of the four fields. In this figure, a structure is shown that operates, senses, and works with a neutral network system to form a new type of adaptive structure.

Structural Health UK has more than 10,000 bridges worth more than 1 million pounds, with millions of bridges going through these bridges through cars and trains every day. NPL is working to improve the health monitoring of structures by developing a wireless sensor integrated system that continuously monitors structures such as bridges. We are also developing new technologies to detect structural changes using digital imaging. By integrating these systems, maintenance and operation costs are reduced, earlier fault warnings are displayed, safety is improved, and the structure may be reworked and it may be too late