Time-domain seismic reliability of nonlinear structures

Abstract

A novel reliability analysis technique is presented to estimate the reliability of real structural systems. Its unique feature is that the dynamic loadings can be applied in time domain. It is a nonlinear stochastic finite element logarithm combined with the response surface method (RSM). It generates the response surface around the most probable failure point and incorporates information of the distribution of the random variables in the RSM formulation. It is verified using the Monte Carlo simulation technique, and is found to be very efficient and accurate. Most sources of nonlinearlity and uncertainty can be explicitly incorporated in the formulation. The flexibility of connections, represented by moment-relative rotation (M-θ) curves, is addressed. After the Northridge earthquake of 1994, several improved steel connections were proposed. Structural Sesimic Design Associates (SSDA) tested several full-scale proprietory slotted web beam-column connections. The authors suggested (M-θ) curves for this connection using actual test data. Behaviours of steel frames, assuming the connections are fully restrained, partially restrained, consisting of pre-and post-Northridge connections are evaluated and compared. Desirable features of the post-Northridge connections observed during testing are analytically confirmed. Laterally weak steel frame is then strengthened with concrete shear walls. Capabilities and the advanced nature of the method are demonstrated with the help of realistic examples.

Seismic Design of Bolted Connections in Steel Structures—A Critical Assessment of Practice and Research

“…In a different time horizon, the approach by Radmehr and Homami [136] may influence connections analysis, with explicit accounting of several significant sources of uncertainty. In fact, reliabilitybased approaches are expected to become increasingly prevalent in seismic analysis and design of structures and components [32][33][34].…”

“…Innovative methods based on seismic reliability, such as [33,34], are expected to assist in the development of new concepts and solutions.…”

A novel reliability technique for implementation of Performance-Based Seismic Design of structures

“…In this representation, fewer elements are required to represent the large deformed configuration and the tangent stiffness matrix can be expressed in an explicit form without integration at the every time step of the time domain analysis. The authors and their team members helped to develop and document the accuracy, efficiency, and capabilities of the software [18][19][20][21][22]. They developed a sophisticated computer program to implement the concept.…”