EAPSI: Numerical and Experimental Investigations of Supplemental Distributed Damping for Seismic Energy Dissipation

Ammons Malcolm L, Ann Arbor MI

Investigators

Abstract

Recent advances in structural systems in conjunction with the proliferation of the use of high performance materials have allowed for structures to become taller and increasingly slender. As such, these structures are highly susceptible to large vibrations induced by extreme loads, particularly those caused by earthquakes or wind events. This can lead to significant economic impact as a result of extensive repairs that are required prior to building re-occupancy. In order to increase the post-event functionality of midrise to super-tall steel structures and better control the structural response and location of damage, this research will assess the ability of strategically placed non-traditional civil engineering materials to reduce structural vibrations. Specifically, high energy dissipating materials such as carbon and polymer foams will be placed within the often underutilized voids of structural members and subjected to large-scale shake table loading to simulate seismic loads. Experimental testing will be supplemented by numerical models that will allow for the assessment of building displacements and accelerations considering different levels and location of the high energy dissipating materials. This research will be conducted at Kyoto University under the guidance of Associate Professor Masahiro Kurata. His expertise in large scale and numerical testing of steel systems, coupled with the facilities of Kyoto University, make Japan an ideal location to conduct this research. The overarching goal of this project is to mitigate the structural response of steel systems under extreme loads. Specifically, the main objectives are to assess the ability of non-traditional civil engineering materials to provide damping under seismic loading and determine what levels and location of this supplemental damping will provide the greatest reduction in structural response. In order to enhance the robustness and resilience of structures, the amount of permanent damage incurred after an extreme event must be minimized. To this end, an existing steel moment frame setup will be utilized with a shake table to simulate the effects of seismic ground motion. Response time histories (displacement, acceleration) and localized damage will be used to assess the performance of the steel frame with and without the supplemental damping system. A significant parametric study utilizing numerical models will augment the experimental testing, and results from both investigations will be used to develop recommendations for the use of non-traditional materials as a means to provide customizable distributed damping. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.