Poster Presentations:
PhD Student Oregon State University
Project Overview and Finite-Element modeling of a Full-Scale Six-Story Hybrid Mass Timber and Steel Building Subjected to Shake Table Motions
Co-Authors: Andre Barbosa (Oregon State University), Arijit Sinha (Oregon State University), Steve Pryor (Simpson Strong-Tie), Patricio Uarac (StructureCraft), John W. van de Lindt (Colorado State University), and Barbara Simpson (Stanford University)
Abstract: The Natural Hazards Engineering Research Infrastructure (NHERI) Converging Design project is a multi-objective, multi-phase collaboration between Oregon State University, Colorado State University, Stanford University, and Penn State University with the goal of developing a new design paradigm in structural engineering. As part of the Converging Design project a full-scale, six-story mass timber building was constructed and tested in three phases at the University of California, San Diego Large High-Performance Outdoor Shake Table. Phase One tested mass timber self-centering rocking walls with cross-laminated timber and mass-ply panels (MPP), distributed energy dissipation provided using U-shaped flexural plates, and post-tensioned threaded steel rods for re-centering. Phase Two replaced the distributed energy dissipation MPP walls with an MPP wall with buckling-restrained boundary elements for providing energy dissipation concentrated across the first story. Phase Three removed the MPP walls again and replaced it with a steel moment frame/concentrically braced frame with yield-link brace connections for energy dissipation and a frame system including yield-link moment connections designed to provide restoring forces.
Besides providing an overview of the project, this presentation will focus on the development of a post-test three-dimensional OpenSeesPy numerical model of Phase Three, which was updated using particle swarm optimization to minimize the error between the comprehensive set of experimental time series obtained during shake table testing and numerical time series of the OpenSees model. Uncertain model parameters were selected for updating to improve global and component-level response. The presented framework enables calibrated simulation of system behavior under unseen seismic loading and supports future applications in areas such as the development of digital twins and performance-based seismic design.
PhD Student Oregon State University
Experimental Dynamic Characterization of Scaled Light Wood Framing Structures Subjected to Storm Surge Loading
Co-Authors: Andre Barbosa (Oregon State Univerisity), Dan Cox (Oregon State Univeristy), Pedro Lomonaco (Oregon State University), and Aaron Anton (Oregon State University)
Abstract: Understanding the dynamic response of coastal residential buildings under storm surge loading is critical for improving the performance of structures exposed to extreme wave hazards. While post-event damage observations are widely reported, experimental evidence linking storm surge demands and its effects on changes in the dynamic properties of a structure and progressive damage remain limited. This study analyzes the damage progression of two 1:3 scaled light wood framing structures tested in the directional wave basin at the Hinsdale NHERI Wave Research Laboratory at Oregon State University. Baseline testing consisted of snap tests, in which a lateral load was applied to each structure and then rapidly released while displacements and accelerations at each level were recorded. In addition to snap tests, ambient vibration measurements and forced vibration tests using an eccentric mass electric motor were performed to further characterize the dynamic response of the structures. Hydrodynamic testing was conducted by subjecting the structures to storm surge loading with progressively increasing water levels. The dynamic properties of each structure were evaluated throughout the wave loading trials and between successive storm surge stages. Progressive damage was assessed by tracking changes in the identified natural frequencies of each specimen over the duration of testing. Results show that storm surge level relative to the first floor elevation strongly influences structural response and damage development. The structure with lower floor elevation experienced higher hydrodynamic demand at earlier stages, leading to earlier damage onset and pronounced elongation of natural periods, while the specimen with the larger first floor elevation exhibited delayed damage progression and smaller shifts in dynamic properties.