Article history: Received 7 February 2012 Available online 13 August 2012 We derive and justify a normal form reduction of the nonlinear Schrödinger equation for a general pitchfork bifurcation of the symmetric bound state that occurs in a double-well symmetric potential. We prove persistence of normal form dynamics for both supercritical and subcritical pitchfork bifurcations in the timedepend...

This paper presents simple analytical approaches for evaluating progressive collapse potential of lowand mid-rise buildings that could be used in routine design by design professionals. Although nonlinear time history analysis would be more realistic in representing progressive collapse phenomenon, high fidelity structural models to represent nonlinear structural behavior are required to produc...

The purpose of this article is to provide an overview adaptive regression modeling and demonstrate its use in conducting nonlinear analyses interrupted time series (ITS) data. Adaptive based on heuristic search over alternative models for data controlled by likelihood-cross validation (LCV) scores with larger indicating better models. Extended linear mixed are used correlated like ITS Power tra...

Probabilistic characteristics of seismic responses of the Partially Restrained connection rotation (PRCR) and panel zone deformation (PZD) installed in older steel moment frames were investigated in accordance with statistical inference in decision-making process. The 4, 6 and 8 story older steel moment frames with clip angle and T-stub connections were designed and analyzed using 2%/50yrs grou...

Probabilistic characteristics of seismic responses of the Partially Restrained connection rotation (PRCR) and panel zone deformation (PZD) installed in older steel moment frames were investigated in accordance with statistical inference in decision-making process. The 4, 6 and 8 story older steel moment frames with clip angle and T-stub connections were designed and analyzed using 2%/50yrs grou...

A damage-based approach for the performance-based seismic assessment of reinforced concrete frame structures is proposed. A new methodology for structural damage assessment is developed that utilizes response information at the material level in each section fiber. The concept of the damage evolution is analyzed at the section level and the computed damage is calibrated with observed experiment...

Hexagrid structural system is an innovated system with structural behavior which is similar to a tubular system. In this paper, a numerical study is conducted to estimate the seismic performance of horizontal hexagrid concerning the combined horizontal and vertical hexagrid, tubular and diagrid structural systems. First 30 and 50 story buildings are modeled using ETABS, then pushover and nonlin...