Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

Pattern Recognition and Machine Learning

This tutorial/survey paper: (1) provides a concise point of departure for researchers and practitioners alike wishing to assess the current state of the art in the control and monitoring of civil engineering structures; and (2) provides a link between structural control and other fields of control theory, pointing out both differences and similarities, and points out where future research and application efforts are likely to prove fruitful. The paper consists of the following sections: section 1 is an introduction; section 2 deals with passive energy dissipation; section 3 deals with active control; section 4 deals with hybrid and semiactive control systems; section 5 discusses sensors for structural control; section 6 deals with smart material systems; section 7 deals with health monitoring and damage detection; and section 8 deals with research needs. An extensive list of references is provided in the references section.

Structural control: past, present, and future

Minimum Design Loads for Buildings and Other Structures provides requirements for general structural design and includes means for determining dead, live, soil, flood, wind, snow, rain, atmospheric ice, and earthquake loads, as well as their combinations, which are suitable for inclusion in building codes and other documents. This Standard, a revision of ASCE/SEI 7-05, offers a complete update and reorganization of the wind load provisions, expanding them from one chapter into six. The Standard contains new ultimate event wind maps with corresponding reductions in load factors, so that the loads are not affected, and updates the seismic loads with new risk-targeted seismic maps. The snow, live, and atmospheric icing provisions are updated as well. In addition, the Standard includes a detailed Commentary with explanatory and supplementary information designed to assist building code committees and regulatory authorities. Standard ASCE/SEI 7 is an integral part of building codes in the United States. Many of the load provisions are substantially adopted by reference in the International Building Code and the NFPA 5000 Building Construction and Safety Code. Structural engineers, architects, and those engaged in preparing and administering local building codes will find this Standard an essential reference in their practice. Note: New orders are fulfilled from the second printing, which incorporates the errata to the first printing.

Minimum Design Loads for Buildings and Other Structures

Recent advances in nonlinear passive vibration isolators

Seismic demands on steel braced frame buildings with buckling-restrained braces

The seismic performance of a posttensioned energy dissipating (PTED) connection for steel frames is investigated analytically and experimentally. The PTED connection incorporates posttensioned high-strength bars to provide a self-centering response along with energy dissipating bars that are able to yield in axial tension and compression. The analytical study involves the development of an equivalent iterative sectional analysis procedure to predict the moment-rotation relationship of the PTED connection. Based on this analytical model, a simple design procedure for PTED connections is described. In the experimental study, a cyclic component test was performed on two energy dissipating bars and a cyclic test was conducted on a large-scale exterior beam-to-column PTED connection. The results of the tests show that the PTED test specimen was able to undergo large inelastic deformations without any damage in the beam or column and without residual drift. The proposed analytical model and design procedure wer...

Posttensioned Energy Dissipating Connections for Moment-Resisting Steel Frames

A simple numerical model to predict the load-displacement response and energy dissipation characteristics of wood shear walls under general quasi-static cyclic loading is presented. In this model the shear wall is comprised of three structural components: rigid framing members, linear elastic sheathing panels, and nonlinear sheathing-to-framing connectors. The hysteretic model for the sheathing-to-framing connector takes account of pinching behavior and strength and stiffness degradation under cyclic loading. A robust displacement control solution strategy is utilized to predict the wall response under general cyclic loading protocols. The shear wall model has been incorporated into the computer program CASHEW (Cyclic Analysis of SHEar Walls). The predictive capabilities of this program are compared with monotonic and cyclic tests of full-scale wood shear walls. It is shown that this model can accurately predict the load-displacement response and energy dissipation characteristic of wood shear walls under general cyclic loading. As an application of the CASHEW program, a procedure is presented for calibrating a single degree-of-freedom system to predict the complete nonlinear dynamic response of shear walls under seismic loading.

Cyclic Analysis of Wood Shear Walls

The seismic response of single-degree-of-freedom (SDOF) systems incorporating flag-shaped hysteretic structural behaviour, with self-centring capability, is investigated numerically. For a SDOF system with a given initial period and strength level, the flag-shaped hysteretic behaviour is fully defined by a post-yielding stiffness parameter and an energy-dissipation parameter. A comprehensive parametric study was conducted to determine the influence of these parameters on SDOF structural response, in terms of displacement ductility, absolute acceleration and absorbed energy. This parametric study was conducted using an ensemble of 20 historical earthquake records corresponding to ordinary ground motions having a probability of exceedence of 10% in 50 years, in California. The responses of the flag-shaped hysteretic SDOF systems are compared against the responses of similar bilinear elasto-plastic hysteretic SDOF systems. In this study the elasto-plastic hysteretic SDOF systems are assigned parameters representative of steel moment resisting frames (MRFs) with post-Northridge welded beam-to-column connections. In turn, the flag-shaped hysteretic SDOF systems are representative of steel MRFs with newly proposed post-tensioned energy-dissipating connections. Building structures with initial periods ranging from 0.1 to 2.0s and having various strength levels are considered. It is shown that a flag-shaped hysteretic SDOF system of equal or lesser strength can always be found to match or better the response of an elasto-plastic hysteretic SDOF system in terms of displacement ductility and without incurring any residual drift from the seismic event. Copyright © 2002 John Wiley & Sons, Ltd.

Seismic response of self‐centring hysteretic SDOF systems

The performance of concentrically braced steel frames and moment resisting steel frames during the January 17, 1994, Northridge, California, earthquake is examined. Most of the observations made du...

/pdf/performance-of-steel-structures-during-the-1994-northridge-2zrzxc1y00.pdf

Performance of steel structures during the 1994 Northridge earthquake

With the development and implementation of performance-based earthquake engineering, harmonization of performance levels between structural and nonstructural components becomes vital. Even if the structural components of a building achieve a continuous or immediate occupancy performance level after a seismic event, failure of architectural, mechanical or electrical components can lower the performance level of the entire building system. This reduction in performance caused by the vulnerability of nonstructural components has been observed during recent earthquakes worldwide. Moreover, nonstructural damage has limited the functionality of critical facilities, such as hospitals, following major seismic events. The investment in nonstructural components and building contents is far greater than that of structural components and framing. Therefore, it is not surprising that in many past earthquakes, losses from damage to nonstructural components have exceeded losses from structural damage. Furthermore, the failure of nonstructural components can become a safety hazard or can hamper the safe movement of occupants evacuating buildings, or of rescue workers entering buildings. In comparison to structural components and systems, there is relatively limited information on the seismic design of nonstructural components. Basic research work in this area has been sparse, and the available codes and guidelines are usually, for the most part, based on past experiences, engineering judgment and intuition, rather than on objective experimental and analytical results. Often, design engineers are forced to start almost from square one after each earthquake event: to observe what went wrong and to try to prevent repetitions. This is a consequence of the empirical nature of current seismic regulations and guidelines for nonstructural components. This review paper summarizes current knowledge on the seismic design and analysis of nonstructural building components, identifying major knowledge gaps that will need to be filled by future research. Furthermore, considering recent trends in earthquake engineering, the paper explores how performance-based seismic design might be conceived for nonstructural components, drawing on recent developments made in the field of seismic design and hinting at the specific considerations required for nonstructural components.

/pdf/performance-based-seismic-design-of-nonstructural-building-4wxwwdjd30.pdf

Andre Filiatrault

Papers

Posttensioned Energy Dissipating Connections for Moment-Resisting Steel Frames

Cyclic Analysis of Wood Shear Walls

Seismic response of self‐centring hysteretic SDOF systems

Performance of steel structures during the 1994 Northridge earthquake

Performance-based seismic design of nonstructural building components: The next frontier of earthquake engineering