Open Guided Waves

Modern society relies on structural health monitoring to assess the condition of mechanical systems and civil infrastructure,ensuring they operate efficiently and safely. While most of studies focus on evaluating structures under controlled or stable lab conditions, a significant number of structures function in uncontrolled and dynamic environments over extended periods.Long-term monitoring in such complex conditions presents additional challenges compared to lab-based assessments. Despite this, few studies address structural health monitoring under these conditions, largely due to the lack of a public benchmark dataset. Such a dataset is crucial for identifying signal features, understanding patterns in guided waves from dynamic environments, and evaluating structural health monitoring methods. To address this gap, this paper presents a public dataset from a long-term outdoor structural monitoring experiment conducted at the University of Utah, Salt Lake City. The monitoring, spanning over 4.5 years, collected approximately 560 million guided waves under both regular environmental variations (e.g.daily temperature changes ranging from −12.2◦C to 52.5◦C, and humidity ranged from 0.5% to 100%) and irregular variations (e.g., rain and snow). The measured guided waves in the public dataset are also affected by sensor drift and installation shifts consistently over time. Additionally, thirteen types of damage were introduced to the monitored structure to support damage detection and severity evaluation under these conditions. The dataset includes measurement times, temperature,humidity, air pressure, brightness, and weather information to aid in damage detection. This paper uses correlation coefficients between adjacent guided waves and optimal correlation coefficients with baseline guided waves to highlight four key challenges in long-term outdoor monitoring: the impact of regular and irregular environmental variations, sensor drift, and installation shifts on guided waves, and the detection of minor damage that causes only slight changes in guided waves. These insights aim to assist researchers in developing more practical methods for structural health monitoring in uncontrolled and dynamic environments.