Principal Investigator Oral Buyukozturk
Co-investigators Hao Sun , Kunal Kupwade Patil , Robert W Haupt , Robert Shin , Huseyin Sadi Kuleli , Thomas Herring , M Toksöz , Ju Li , John Fisher , Fredo Durand , William Freeman , Christoph Reinhart , John Ochsendorf , Markus Buehler , Sidney Yip
Project Website http://web.mit.edu/liss/#/seismic
Current procedures for the design of earthquake (EQ) resistant structures generally consider lateral forces induced by the strong ground motion as equivalent static loads. Design codes such as FEMA356 (2000), Eurocode, Turkish Earthquake Code (2007), and ASCE/SEI 7-10 (2010) are mainly based upon strength and displacement capabilities a structure. However, another criterion known as “Energy” can be formulated and utilized in order to relate the forces acting on the system and the respective response. Since this approach encompasses both the duration and frequency content of the earthquake and the structural response into its formulation, it is accepted that the use of energy concepts appears to have significant potential towards improving the computation of seismic demands and the design of systems. Shown below, despite the fact that the Chile Llolleo 1985 and the San Salvadore 1986 earthquakes have very similar response spectra, they have vastly different energy spectra, which is important to consider for the design of structures.
The objective of this collaborative project is to better characterize energy-based design (EBD) concepts and seismic energy demand distributions with a comprehensive experimental study at STEELab in Istanbul Techincal University, Turkey, through a new framework for correlating analytical, finite element, and physical models, as a basis to provide design recommendations for new structures to better resist earthquake hazards. Laboratory tests will be conducted on both single degree of freedom (SDOF) systems and modular multiple degrees of freedom (MDOF) systems, on a shake table setup to validate the energy spectrums numerically developed by the researchers in the literature. Novel data acquisition techniques, such as a laser vibrometer and video camera methods using optical flow or digital image correlation, which provide velocity and displacement data, in addition to traditional accelerometers and strain sensors, will be used to calculate the energy components, given known material characteristics.