###### Abstract  
This paper presents the implementation of a synchronous Structural Health Monitoring (SHM) framework utilizing wireless, low-cost, and off-the-shelf components. Vibration-based condition monitoring plays a crucial role in assessing the reliability of structural systems by detecting damage through changes in vibration parameters. The adoption of low-cost Micro-Electro-Mechanical Systems (MEMS) sensors in Wireless Sensor Networks (WSNs) has gained traction, emphasizing the need for precise time synchronization to schedule wake-up times of multiple sensor nodes for data collection. To address this challenge, our proposed method introduces a TCP/IP socket programming-based mimic broadcasting mechanism and a scalable sensing network controlled by a central gateway, leveraging the Raspberry Pi Python platform. The system operates using Internet of Things (IoT) concepts and adopts a star topology, where a packet is transmitted from the gateway to initiate measurements simultaneously on multiple sensor nodes. The sensor node comprises a MEMS accelerometer, a real time clock DS3231 module and Raspberry Pi Zero 2W (RFi0-2W), while the gateway employs a Raspberry Pi 4 (RFi4). To ensure accurate time synchronization, all Pi0-2W nodes were configured as Network Time Protocol (NTP) clients, synchronizing with an RPi4 server using chrpy, the reliable implementation of the NTP. Through experimental evaluations, the system demonstrates its effectiveness and reliability in achieving initial time synchronization. This study addresses the challenge of achieving precise time alignment between sensor nodes through the utilization of the Dynamic Time Wrapping (DTW) method for Frequency Domain Decomposition (FDD) applications. The contribution of this research significantly enhances the field by improving the accuracy and reliability of time-aligned measurements, with a specific focus on utilizing low-cost sensors. By developing a practical and cost-effective SHM framework, this work advances the accessibility and scalability of structural health monitoring solutions, facilitating more widespread adoption and implementation in various engineering applications  
structural health monitoring; vibration-based condition monitoring; wireless sensor networks; time synchronization; low-cost accelerometers; dynamic time wrapping; frequency domain decomposition; raspberry pi +
Footnote †: journal: Applied  
0202414349414349414349414349414349414349414349414349414349414349414349414349414349414349414434 safety and economic stability. SHM entails the continuous surveillance of structures to detect and evaluate potential damage or degradation, enabling proactive maintenance and minimizing the risk of structural failures. An essential facet of damage detection in structural systems involves the observation of changes in structural modal parameters, particularly natural frequencies. These modal parameters serve as invaluable indicators of potential damage within the structure. Among the array of methodologies employed in SHM, vibration-based techniques have emerged as particularly favored, owing to their high sensitivity in discerning subtle structural alterations and their non-intrusive nature, rendering them ideally suited for long-term monitoring endeavors. Vibration-based methods in SHM utilize the inherent dynamic characteristics of structures to identify and quantify damage [1]. These methods rely on the measurement and analysis of vibration signals induced by external forces or internal excitations. In addition, vibration measurement plays a crucial role in non-invasive fault detection and prediction of rotating machine components [2]. Sensors play a pivotal role in acquiring accurate structural responses. Conventional force balanced accelerometers have been conventionally employed for capturing structural behavior [3].