State-Dependent Fragility via Experimentally Validated Energy-Based Approaches

This paper presents the preliminary results of the ENFRAG research project, which is part of the ERIES project (engineering research infrastructures for European synergies). ENFRAG aims at advancing state-dependent earthquake fragility assessment methodologies. The project involves sequential quasi-static cyclic displacement-controlled in-plane (IP) and shaking-table dynamic out-of-plane (OOP) tests on four nominally identical infill walls. Different load protocols are employed to induce the same peak-based engineering demand parameters (EDPs) while modulating the energy-based demands. A multi-fidelity approach is employed to integrate the experimental data with synthetic datasets including IP cloud-based analysis, IP quasi-static, push-pull analyses with different load protocols, OOP dynamic analyses, and IP-OOP combined analyses. The results are used to explore the potential of energy-based EDPs for interpreting damage states and damage accumulation. This allows experimentally validating methodologies to derive state-dependent fragility functions that account for multiple sources/mechanisms of damage accumulation. This contribution provides an update on the numerical and analytical components of ENFRAG, as well as linking them with the specific research objectives.