Footbridge solutions with natural fibers
Ali Shahmirzaloo defended his PhD thesis at the Department of Built Environment on April 9.
Natural Fiber Reinforced Composites (NFRCs) are emerging as sustainable alternatives to conventional materials in various engineering applications. NFRCs are typically manufactured by layering multiple fiber sheets, which can be applied as woven or non-woven fabric, within a polymer matrix. The multilayered structure is critical towards achieving the desired mechanical properties and enhancing the material鈥檚 performance under structural loads. This configuration enables NFRCs to combine the inherent strength of natural fibers with the flexibility and durability of polymer matrices, making them suitable for lightweight and high-strength applications. For his PhD thesis, Ali Shahmirzaloo investigated the application and challenges of NFRCs in civil engineering, focusing on their use in footbridge construction.
The PhD thesis of Ali Shahmirzaloo begins by exploring the potential of NFRCs, addressing their environmental benefits, material properties, and barriers to widespread adoption, such as high production costs and the lack of comprehensive standards.
Material characterization
Shahmirzaloo鈥檚 thesis then delves into the characterization of NFRC materials through experimental studies, specifically examining a flax fiber-reinforced polyester composite used in a largescale footbridge model.
For the NFRC bridge in this project, a new design methodology was proposed to address the absence of building codes. This methodology was validated through static testing of the large-scale beam.
The validation process involved comparing finite element analysis (FEA) results with strain and displacement values obtained through in-situ measurements.
Building process and management
Subsequently, the thesis demonstrates the entire building process鈥攆rom material testing to static performance evaluation before installation, and the implementation of a bridge management framework to ensure long-term safety.
Long-term performance evaluation
The final part of Shahmirzaloo鈥檚 research evaluates the long-term performance of NFRC materials by estimating the endurance limit using a thermographic method offering a rapid alternative to traditional fatigue strength assessment techniques.
The study highlights the prospects of bio-composite applications and explores emerging trends in novel bio-composites for future structural applications.
Title of PhD thesis: Supervisors: Faas Moonen, Patrick Teuffel and Davide Leonetti.