Performance-based design is a major shift from traditional structural design concepts and represents the future of earthquake engineering. The procedure provides a method for determining acceptable levels of earthquake damage. Also, it is based on the recognition that yielding does not constitute failure and that preplanned yielding of certain members of a structure during an earthquake can actually help to save the rest of the structure. In this technology-packed seminar, Ashraf will present the theory and practical application of nonlinear analysis and performance-based design in terms and analogies that are very familiar to the practicing structural engineer. Attendees will leave the seminar empowered with a clear understanding of this new technology.

Registration: $125 per person
Thursday, May 15, 2014 - 8am - 4pm
Westin LAX - 5400 West Century Blvd., Los Angeles, CA 90045

Registration Includes:

Textbook: ”Modeling for Structural Analysis" by Professor Graham Powell (value: $150)
Continental breakfast, luncheon, and refreshment breaks
Gift drawings and prizes you won’t want to miss

Register Now

IMPORTANT NOTE: No PDH credits are offered for this seminar, however attendees may request a certificate of completion.

ATTENTION STUDENTS: For future leaders of our profession, a limited number of complimentary student registrations are available. Applications will be accepted until Monday, May 5, or until all student slots are filled. Please email your student ID and resume to

The seminar will address many fundamental questions, such as:

  • Why do we even need to talk about nonlinear analysis?
  • What is really meant by energy dissipation and why it is important?
  • What is a time-energy diagram and why is it so important in seismic design?
  • What is deformation capacity and why it is more important than strength capacity?
  • What we really mean by ductility and why strength without ductility is useless?
  • What is a material model, a fiber model and a hysteresis loop?

And, elaborate on many interesting observations, for example:

  • ... that structures can be designed to follow predefined paths of damage to preserve critical components.
  • ... that allowing yielding of parts of a structure during an earthquake can save the rest of the structure.
  • ... that yielding does not mean failure and some structures can have more strength after yielding.
  • ... that the most efficient and accurate nonlinear time history analysis technique is based on mode superposition.
  • ... that most dead load analyses assume that a structure is built weightless and gravity appears instantaneously.
  • ... that a nonlinear time history analysis is important even for a regular high rise structure.

Nonlinear Theory

  • Material and geometric nonlinearity
  • Steel and Concrete behavior in the nonlinear range
  • P-delta and large displacements
  • Yielding and energy dissipation
  • History dependence
  • Ductile and brittle behavior
  • Ductile limit and strength loss
  • Elastic and plastic energy
  • Cyclic stiffness and strength degradation, and fatigue
  • Hysteresis loops and time-energy diagrams
  • Redundancy and resilience
  • Strength based design and deformation based design
  • Problems of design by analysis
  • Capacity design and sacrificial elements
  • Collapse mechanisms
  • Sustained and cyclic loads

Nonlinear Modeling

  • Material models, moment, axial and shear hinges FEMA hinges
  • Rusty hinge model
  • Moment axial force interaction
  • Fiber hinge models for complex shapes
  • Multi layered nonlinear shell model
  • Multi linear elastic and plastic behavior
  • Viscous dampers
  • Base isolation energy dissipating models
  • Types of hysteresis loops - kinetic, isotropic, Takeda and pivot
  • Special considerations for tall building

Nonlinear Analysis Techniques & Performance Based Design

  • The FNA time history analysis method and the power of Ritz vectors
  • Step by step nonlinear time history analysis
  • Large-displacement and P-delta effects
  • Modal and Rayleigh damping
  • Nonlinear events and element state determination
  • Unloading events, redistribution and solution complications
  • Requirements of ASCE41Pushover analysis and limitations
  • Force controlled loading and displacement controlled loading
  • Badly behaved displacements (snap-back and snap-through)
  • Non-uniqueness of static solutions, uniqueness of dynamics
  • Acceleration Displacement Response Spectrum (ADRS)
  • Push over curve and target displacement Equivalent linearization and displacement modification methods
  • Performance measures and performance levels
  • Demand/capacity ratio and acceptance criteria
  • Soil-structure interaction

Nonlinear Applications in Structural Engineering

  • Buckling restrained braces
  • Eccentrically braced systems
  • Base isolation systems
  • Reduced beam sections
  • Panel zone plasticity
  • Foundation uplift and structural pounding
  • Long term creep and shrinkage
  • Effects of construction sequence loading
  • Nonlinear dampers and deflection control
  • Tension only bracing systems
  • Cable supported structures

About Ashraf Habibullah, S.E.

Ashraf Habibullah, Registered Civil and Structural Engineer, is President and CEO of Computers and Structures, Inc. He founded CSI in 1975. Today, CSI is recognized globally as the pioneering leader in the development of software tools for structural and earthquake engineering. The software is used by thousands of engineering firms in over 160 countries. CSI products are also recognized as the standard tools for research and education worldwide and CSI has donated software to thousands of universities for teaching purposes. Through these donations, CSI has helped to ensure that the technology necessary to produce seismically-sound structures reaches everyone. Ashraf has led the development of CSI's products for nearly four decades and has been very active as a consultant, researcher and educator, conducting international courses and seminars on analytical techniques and numerical methods used in software for Structural and Earthquake Engineering.