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Robustness, system modelling, risk analysis.

Bio

Dr. Alex Sixie Cao will join the School of Civil and Environmental Engineering, Nanyang Technological University (NTU) as a tenure-track Assistant Professor in the summer of 2026, where he will lead the Risk and Infrastructure Systems Lab. His work integrates structural mechanics, probabilistic modelling, and risk-informed decision-making to design infrastructure systems that remain safe, adaptive, and resource-efficient under changing climatic and societal conditions.

Alex is currently a Postdoctoral Researcher at Empa and ETH Zurich (2024 - 2026) with Dr. Pedro Palma and Prof. Andrea Frangi, working on robustness, probabilistic system modelling, impact resistance, and the reliability of timber connections under complex loading. He earned his PhD in Civil Engineering from ETH Zurich in 2024, developing analytical and numerical tools for progressive collapse and robustness of timber buildings, supported by full-scale impact testing and analytical modelling. His earlier studies at NTNU (2015 - 2020) and Tsinghua University (2018 - 2019) built a foundation in structural dynamics, continuum mechanics, and wind engineering. He is active in the Joint Committee on Structural Safety (JCSS) and international standardization efforts on robustness, progressive collapse, and timber engineering.

Research Interests

  • Robustness and progressive collapse. System-level damage propagation, load redistribution, impact and dynamic amplification; modelling and experiments for robustness; reliability of timber connections and components under complex loading.
  • Societal risk acceptance and safety targets. How climate change, carbon pricing, and societal preferences shape the societal risk acceptance and target reliability; risk-based optimization using ALARP, LQI, and MLSC frameworks.
  • System modelling. Non-stationary probabilistic system models for structure and infrastructure systems.

Selected Publications

Full list of publications on Google Scholar or ResearchGate.

Cao, A. S.; Beck, A. T. (2025), On the quantification of robustness and its thresholds, Structural Safety (under review)

Cao, A. S.; Thöns, S.; Palma, P.; Frangi, A. (2025), Dynamic amplification factors in instantaneously loaded structures, Engineering Structures, 345, 121464 , DOI

Iannacone, L.; Cao, A. S. (2025), Influence of attacker’s prior knowledge on the performance of redundant systems, ICOSSAR 2025, Los Angeles, USA , DOI

Cao, A. S.; Esser, L.; Frangi, A. (2024), Modelling progressive collapse of timber buildings, Structures, 62, 106279 , DOI

Cao, A. S.; Houen, M.; Frangi, A. (2024), Impact loading of glued laminated timber beams without finger-joints, Computers & Structures, 296, 107278 , DOI

Cao, A. S.; Grönquist, P.; Frangi, A. (2023), Catenary action in strip-reinforced wood and timber beams, Construction and Building Materials, 385, 131422 , DOI