PSI - Issue 78

Florence More et al. / Procedia Structural Integrity 78 (2026) 944–951

948

tensioned elements.

Table 1. Development and advancements in Structural Health Monitoring of Timber Structures

Author

Country

Objectives

Sensors

• 15 uni-axial accelerometers, PCB model 393B12, with a sensitivity of 0.5 V/g for vibration. • 120 Sensirion SHT35 sensors were installed in groups across 18 different points. • Permanent monitoring system with three piezoelectric accelerometers and a weather station with an anemometer and temperature and humidity sensors. Eleven sensors on internal and external walls across the building’s interior to determine moisture

Amaddeo et al. (2025) Aloisio et al. (2025) Placide et al. (2022) Placide et al. (2020) Han et al. (2020) Jiang et al. (2019) Leyder et al. (2015) Dietsch et al. (2015) Hayashi et al. (2010)

Permanent monitoring of the 6-storey Hus 37 building.

Sweden

Long-term continuous dynamic monitoring of an eight-story building that is entirely CLT.

Norway

Laboratory (Germany) Laboratory (Germany) Laboratory (China)

Evaluation of the durability of glulam under cyclic moisture stresses. MC monitoring of glulam structures by surface electrodes embedded between the lamellae. Damage location factor and the damage size factor of timber specimens are investigated Two-story Chinese ancient timber building monitored through FBG sensors. Influence of the environmental effects on the structural behavior. Long-term measurements of timber MC, temperature and relative humidity in a total of 21 buildings with seven different types of use were carried out Monitoring of the seasonal variation and temporal change in vibration characteristics of traditional timber structures in the Higashi Honganji temple.

• Electrical MC sensors

• Electrical MC sensors

• Electromechanical impedance method

• Deflection (56 FBG sensors), 4 inclinometers, 3 temperature and humidity sensors and 3 smoke alarms • Load cells, MC (electric resistance method) and deformation measurements (tachymeter measurements).

China

Germany

Germany

• Electrical resistance measurement

Japan

• Accelerometers

Their results indicated a strong correlations between moisture content and post-tensioning force loss, while temperature effects were shown to influence structural behaviour indirectly through their impact on indoor humidity. Despite these variations, structural deflections and dynamic responses remained within acceptable limits, highlighting the resilience of well-designed engineered timber systems under real-world conditions. A broader European perspective on timber monitoring methods was offered by Kurz et al. 2015 who evaluated the applicability of advanced NDT techniques such as ultrasonic testing, thermography, microwave imaging and acoustic emission. Their analysis, conducted under COST Action FP1101, emphasized the importance of integrating NDT with SHM strategies to detect internal defects and fatigue behaviour without invasive methods. The study also stressed the impact of moisture on mechanical properties and structural longevity, advocating for the development of moisture-sensitive diagnostic tools. Moisture was further identified as a fundamental factor in timber degradation by Dietsch et al. 2015 who monitored 21 glulam roof structures across Germany. Their study distinguished between heated and unheated buildings, showing that the former maintained stable moisture levels (8 – 10%) and experienced minimal cracking, whereas the latter, especially agricultural or uninsulated facilities, exhibited moisture content variations up to 17%, often leading to lamella cracking. These findings introduced the Equilibrium Moisture Content (EMC) concept as a critical parameter in design and maintenance, reinforcing the value of climate-responsive building systems. In the context of heritage preservation, Jiang et al. 2019 proposed a low-intrusive SHM solution using fibre Bragg grating (FBG) sensors in the 257-year-old Seven Literary World building in China. The system monitored beam deflection, column inclination and environmental variables, validated through numerical modelling and long-term field data. Their approach demonstrated that high-resolution SHM can be successfully applied to historic timber structures without compromising architectural integrity, thereby enabling predictive maintenance and improved risk assessment. Another significant advancement in timber diagnostics was introduced by Han et al. 2020 through the application of the Electro Mechanical Impedance (EMI) method. Their laboratory-based study conducted on pine