My research focuses on the enhancement of seismic resilience of buildings through implementation of innovative technologies, particularly for steel structures. Nonlinear structural modeling under dynamic excitation and implementation of performance-based design and assessment methods are indispensable for this purpose. My research activities can be categorized in two main areas: 1) development of state-of-the-art numerical modeling for earthquake engineering simulation based on large-scale experimentation 2) development/refinement of simplified and advanced methodologies for seismic design, assessment, and retrofit of buildings equipped with passive energy dissipation devices.


  • Structural dynamics
  • Advanced nonlinear modeling and analysis of structures
  • Seismic retrofit of existing steel buildings
  • Passive energy dissipation devices and base isolation systems
  • Performance-based earthquake engineering
  • Seismic design of steel tall buildings, moment-resisting frames, concentrically braced frames and buckling-restrained braced frames, cold-formed steel shear walls.
  • Simplified evaluation methodologies, linear and nonlinear, static and dynamic procedures
  • Displacement-based seismic design


Uniaxial material models for nonlinear viscous dampers and bilinear oil dampers have been implemented into the Open System for Earthquake Engineering Simulation (OpenSees) platform via C++ programming.

  • ViscousDamper: A new uniaxial material model, which simulates the dynamic response of nonlinear viscous dampers, including its axial stiffness and gap length of clevis. An example is provided to demonstrate the use of viscous damper material within a simple single story shear frame.
  • BilinearOilDamper: A new uniaxial material model, which simulates the dynamic response of oil dampers with a relief valve, including its axial stiffness and gap length of clevis.


Akcelyan, S., Lignos, D. G., Hikino, T. (2018). “Adaptive numerical method algorithms for nonlinear viscous and bilinear oil damper models subjected to dynamic loading.” Soil Dynamics and Earthquake Engineering, (accepted).

Akcelyan, S., Lignos, D. G.,  (2018). “Seismic retrofit of steel tall buildings with bilinear oil dampers.” Proceedings of the 16th European Conference on Earthquake Engineering, Greece.

Akcelyan, S., Lignos, D. G., Hikino, T., and Nakashima, M. (2016). “Evaluation of simplified and state-of-the-art analysis procedures for steel frame buildings equipped with supplemental damping devices based on E-Defense full-scale shake table tests.” Journal of Structural Engineering, 142(6), 04016024.

Akcelyan, S., (2018) “Seismic retrofit of existing steel tall buildings with supplemental damping devices.” Ph.D. Dissertation, McGill University, Canada.

Akcelyan, S., “Seismic analysis and evaluation of steel structures with viscous dampers.” Oral presentation during the OpenSees Days 2013 Workshop at Richmond field station at UC Berkeley. August 2013. <>.

%d bloggers like this:
search previous next tag category expand menu location phone mail time cart zoom edit close