Component-level integration of embedded 3D-printed piezoresistive sensors for real-time strain monitoring of a load-bearing pylon structure

Structural Health Monitoring (SHM) is essential for ensuring the longevity and safety of critical infrastructure. While additive manufacturing (AM) has enabled the development of low-cost, embedded piezoresistive sensors, most existing research remains confined to laboratory-scale coupons, presenting a clear gap in component-level structural integration. Rather than proposing a new sensor material or geometry, this study focuses on the component-level integration of a pre-validated 3D-printed piezoresistive sensor geometry (adopted from Musa et al.) into a geometrically complex, load-bearing pylon component via multi-material Fused Deposition Modeling (FDM). Conductive PLA sensors were encapsulated within a structural PLA body during a single manufacturing operation. Sensor locations were selected based on Finite Element Analysis (FEA) strain topology predictions. A redundant sensing architecture was established, and electromechanical performance was validated under tensile loading using 3D Digital Image Correlation (DIC) for full-field surface strain verification. Strong linear electromechanical behavior ( to ) was recorded up to a localized strain of 2.1%. Baseline electrical resistances ( ) ranged from to , while Gauge Factors (GF) varied from to . The redundant sensor network successfully detected asymmetrical strain distributions caused by off-axis loading misalignment in real-time. Transient multi-step loading profiles confirmed rapid electromechanical tracking with minimal viscoelastic lag during short-term hold periods. A practical laboratory-scale framework was established for embedding piezoresistive sensors within complex polymer structures, laying a foundation for future self-sensing structural applications.