Organizations that deploy structural health monitoring (SHM) systems can take advantage of two main benefits: they can reduce maintenance costs by only conducting maintenance when it is needed, and can increase the lifetime of structures by detecting damage early for a proactive response. The SHM market is rapidly growing due to the advantages posed by these systems, however, there are some current limitations with existing systems that hinder widespread adoption.
Key Challenges for Structural Health Monitoring Systems
First, purchasing a structural health monitoring system is not a commodity purchase. Design work for each structure is necessary whether the SHM system is going to be implemented on an existing structure or a new construction. Due to the engineering costs and lack of resource availability associated with incorporating a SHM system into a structure, many organizations opt to forego deploying one. Unfortunately, businesses that make this decision lose out on the long term savings provided by a SHM system which far outweighs the upfront cost.
Many structural health monitoring systems rely on point sensors, or sensors that obtain data about only one point, to monitor assets. The limitations to point sensors are not about accuracy or reliability, rather it is about insight. Events that occur between critical points will be missed so structural response information will be lost. Using point sensors in SHM systems is limiting since these systems must use interpolation to simulation additional measurement locations. This practice leads to biased damage indices since true local information is lost.
Another challenge that faces many existing structural health monitoring systems is data normalization. This is the process of separating changes in sensor output caused by damage and changes caused by varying environmental conditions. Since most SHM systems do not continuously monitor, it is difficult to normalize the data—especially when point sensors are used to collect the information.
How Fiber Optic Sensing Can Help
Distributed strain data provided by a fiber optic sensing platform can help overcome some of the challenges discussed above. Sensuron developed a SHM system in conjunction with NDE software experts Ensyso that can be fully automated and can detect local damage through the use of global vibration information. The system is able to detect the existence, determine the location, and quantify the severity of the damage with high accuracy irrespective of the size of the inflicted damage. In doing so, the system helps overcome some of the challenges listed above. Since the dense sensor layout collects local damage information, the system relies less on interpolation and will capture information about critical areas, rather than just critical points. Additionally, the system can continuously collect data so that it is easier to attribute changes to environmental conditions versus actual damage.
Although incorporating fiber optic sensing into a structural health monitoring system will not make the purchase more of a commodity purchase, it will help increase the long term benefits and ease of use. Over time, as adoption of SHM systems increases fiber optic sensing will play a larger and larger role in the industry.
Download the case study below for more information about Sensuron’s SHM system.