Hysteretic models for cyclic behavior of deteriorating inelastic structures

The purpose of this report is to provide a theoretical basis for a range of rule-based piecewise linear hysteretic models (in Section 2), as well as differential equation-based smooth hysteric models (in Section 3). Also to provide a sound and formal reasoning for the basis of the above-mentionedmodels that are founded on the fundamentals of mechanics and the interrelationship between these various types of models (in Section 4). This research fits in with two more of MCEERïs missions: outreach to the professional user community; and to extend the fundamental knowledge base to enable a high level of computational simulation to be conducted

IDARC2D version 4.0 : A computer program for the inelastic damage analysis of buildings

This report summarizes the modeling of inelastic structures and enhancements to the program series IDARC developed for analysis, design and support experimental studies. This report presents a synthesis of all the material presented in previous reports NCEER-87-0008, NCEER-92-0022 (and in other related reports). This report presents also the new developments regarding modeling of inelastic elements and structures with supplemental dampimg devices, infill panels, etc. (AU)

Nonlinear control techniques for dynamical systems with uncertain parameters

The present report explores various approaches for controlling nonlinear uncertaim dynamical system. Several models representing different types of nonlinearities in such systems are considered. In particular, the Duffing oscillator and a system coupled to an electro-rheological device are considered. This latter system nonlinearity is characterized by a nonlinear force versus velocity relationship which is itself a function of an external voltage applied across the device. The control objectives considered in the present study consist of trajectory tracking (AU)

The advantages of using computer software for process hazard analysis (PHA)

Computer systems have greatly increased our overall efficiency and quality of work. The use of software to perform PHAs has been steadily increasing since the early 90's. PHAs, especially HAZOPs, place considerable demands on facilitators and team members. since PHAs are time consuming and fairly costly attention must be paid to the increase in efficiency afforded by computerization. In addition, documentation and auditability are significant concerns. The paper examines the user end goals, factors in developing the user interfase, filing and data storage, the use of risk matrices and knowledge based libraries, different PHA methodologies to be considered and some common misconceptions about PHA software. The process of envolving and developing new canadian software, DDM - HAZOP, is described (AU)

Consistency in computational methods for flood insurance studies

This paper presents the computational methods used in the unsteady flow models UNET, FEQ, and adICPR. The different results from analyzing infiltration losses for hydrologic models, friction loss methods in water-surface profiles computations, losses at the bridges and culverts, and the use of hydraulic grade line and energy grade line computations in storm sewer analysis are discussed. Consistent computational methods should be established so that the results will be the same no matter which computer program is used for a particular type of flow. FEMA is responsible for publishing flood insurance rate maps for the entire nation. The maps and profiles are based on the results obtained from computer models, and it is important that consistent methods are used in the computer programs to produce consistent results. A unified computer program agreed upon by the hydraulic community may be the best solution to the consistency problem, but is unrealistic. Another solution to the consistency problem is to set specific guidelines for flood insurance mapping and require that the computer programs comply with these guidelines

Seismic protective systems for computers and data processing equipment

Data processing installations, intelligent workstations, personal computers and related types of equipment are vital to the successfull operation of business, education, research, service and industrial operations in today's world. Any interruption in the operation of data processing or computer equipment can halt or significantly impact the operation of business activity. Especially important are such items as on-line banking, process controls, communications, hospitals and emergency facilities. This scenario, coupled with the occurrence of an earthquake, can lead to total chaos if the coputers fail due to the earthquake shock and vibration effects.(AU)

A knowledge - based design system for the design of freeway and highway bridges in Taiwan

Bridge design and construction are two of the most time consuming and expensive tasks of the Six-Year National Development Plan in Taiwan. Bridge construction engineering is the critical control job in freeway and highway construction. Reducing the design labor and time in the preliminary bridge design stage is important to ensure that the project is completed on time for freeway and highway construction and renovation. A related computer-aided design system called TBDS for freeway and highway bridges in Taiwan is introduced for this purpose. Both the domain experts' and knowledge engineers' experiences during the development of TBDS are described. Finally, the future directions of this research will be discussed.(AU)

Computer assisted decision making for emergency response in New Brunswick

The emergency response community in New Brunswick is turning to computers to assist in reaching timely and effective decisions. This paper describes the use of computers in New Brunswick to assist emergency managers in making decisions during emergency response operations, including: the use of computers on - site, computer communications from the emergency site to an emergency operations centre, use of computers in the emergency operations centre, computers communication between emergency operations centres, and some past applications during actual emergencies. The paper cpncludes with current shortcomings and a look to the future (AU)

Dealing with uncertainty in automated decision support systems for emergency response scenarios

In an emergency response scenario, on scene commanders will have to rapidly formulate a viable course (plan) of action while being confronted with an atmosphere of considerable uncertainty are incomplete information and an over - changing and unpredictable, situation. Any automated Decision support system will have to cope with this uncertainty in a way that is easily understood by the user and the flexible enough for the user to modify to cater for situation specific factors. The particular emphasis in an emergency scenario is rapid action and there will not be any time to carry out extensive environmental impact assessments of the various possible courses of action using many of the curently used techniques. This paper gives an overview of some of the principal techniques currently used to deal with uncertainty and their automation implications. It them proposes a metric, along with a knowledge acquisition strategy, which assesss the relative advantage or disadventage of adoption a particular course of action, evaluates this advantage or disadventage relative to its overall Relevance in a particular scenario and then carries out two overall assessments of this course of action in accordance with Least Risk and Best Advantage criteria. Several possible courses of action are compared and the best one is selected based on a comparison of their overall assessments (AU)

The emergency site management system : An extension of the incident command system

This article outlines a framework for the management of disasters at community level involving multi organizational and multi jurisdictional effort. The article acknowledges that a number of disaster management systems exit and are applied by fire departments across North America. However, it is also argued that many of these systems have limited application outside fire departments, and that what municipal response organizations require is a system which is flexible, adaptable, and consistent with the other realities of the disaster response environment. The Emergency Site Management (ESM) system is more closely aligned with the needs of municipalities than any other disaster management system. It permits municipal elected officials and their representatives to maintain their authority over disaster operations. The ESM system is also more inclusive and maximizes the coexistence of varying jurisdictional authorities. It permits the incorporation of a broad range of support from agencies external to the municipality. It emphasizes coordination rather than simply the command of disaster operations. Moreover, it facilitates the flow of information despite a breakdown of one or more organizational linkages. The ESM system is based on two key organizations : one located at the site, the other at the community's Emergency Operation Centre (EOC). Each consists of three operational circles, the primary of which includes representatives of the key response agencies. The site team is managed by a site manager while the EOC team is typically managed by the Town Clerk or other senior administrator (AU)

Un sistema de medida de la amplitud sísmica en tiempo real (RSAM)

Aunque existen varios sistemas para el registro y detección de terremotos en tiempo real, pocos tratan el problema de vigilar continuamente la amplitud de las señales sísmicas durante condiciones de crisis volcánica, cuando los eventos individuales son difíciles de reconocer. Nosotros desarrollamos un sistema de medida de amplitud sísmica en tiempo real (RSAM-Real-time seismic-amplitude measuremen system) que usa un convertidor económico analógico-digital de ocho bits que es controlado por una computadora portátil para proporcionar información sobre amplitud absoluta promediada cada minuto para ocho estaciones sísmicas cerca del Mount St. Helens. El nivel de voltaje absoluto para cada estación es digitalizado a una frecuencia de 60 muestras/segundo, promediado e inmediatamente transmitido a una computadora central para su análisis. El RSAM proporciona una historia continua de la actividad sísmica que es fácil para accesar. Sistemas de RSAM, que calculan el promedio de amplitudes por espacios de 10 minutos, han sido instalados en los observatorios vulcanológicos de Cascades, Alaska y Hawaii. El RSAM ha sido una herramienta útil para la predicción de actividad eruptiva en los volcanes Mount St. Helens y Redoubt, Alaska

Un sistema para la adquisición, archivo y análisis de datos de tiempo - serie de baja frecuencia en tiempo casi real

La interpretación oportuna de datos es esencial para la vigilancia volcánica. Yo desarrollé un sistema en el Observatorio Vulcanológico Cascades (CVO) para la adquisición y el despliegue en forma gráfica, en tiempo casi real, de datos de baja frecuencia (frecuencia de muestreo igual o menor a un minuto). Los datos de redes telemétricos de baja frecuencia de datos y del sistema de amplitud sísmica de tiempo real son transferidos a una computadora central cada 10 minutos y un minuto, respectivamente. Los datos recolectados manualmente son entrados manualmente a la compuadora central, mientras que los datos de redes telemétricas remotas son recolectados semanalmente mediante un sistema telefónico. En la computadora central, el programa BOB que desarrollé en el CVO, facilita la interpretación de los datos al presentarlos de manera gráfica. Aunque el CVO la computadora central es una VAX 11/750, también se puede correr el sistema en IBM PC XT/AT o compatible como computadora central, haciéndolo más portátil (AU)

Sistemas para la adquisición de datos sísmicos en el Observatorio Vulcanológico Cascades

Entre fines de 1987 hasta principios de 1990 el Observatorio Vulcanológico Cascades (CVO-Cascades Volcano Observatory) instaló y operó dos sistemas diferentes para la adquisición de datos sísmicos de una pequeña red sísmica. Los sistemas estaban configurados para detectar y registrar pequeños sismos que ocurrían debajo del Mount St. Helens de la red de 14 a 16 estaciones sísmicas. El primer sistema de adquisición de datos es un sistema PC/AT, que utiliza los programas distribuidos por la Asociación Internacional de Sismología y Física del Interior de la Tierra (IASPEI-International Association of Seismology and Physics of the Earth's Interior). El segundo sistema usa una estación de trabajo Sun, con un subsistema analógico a digital con una interfaz SCSI, y programas para la adquisición de datos escritos para computadoras que usan el sistema operativo UNIX. La operación de los dos sistemas en 1989 le dio la oportunidad al CVO para evaluar los dos sistemas económicos de adquisición de datos sísmicos digitales. Fue fácil instalar los dos sistemas que funcionaron según lo esperado (AU)

El programa LINCE una aplicación informática para la evaluación de riesgos y el control de emergencias

El desarrollo tecnológico de la sociedad ha añadido nuevos riesgos a los ya conocidos por el hombre y con resultados equiparables a los más graves desastres de origen natural. El programa informático LINCE es una demostración de cómo la informática puede ser de gran utilidad cuando se trata de hacer frente situaciones de emergencia en la que la rapidez de respuesta y la agilidad en la toma de decisiones puede resultar de capital importancia (AU)

Source process of some large earthquakes in Greece and its tectonic implication

In the present paper the source process of some large earthquakes occurred in Greece is discussed in terms of the distribution of the asperities or barriers on the fault plane. The source process has been revealed by the inversion of teleseismic long period body waves using two different techniques. Based on the obtained source time functions an attempt is made to explain the low stress drop values for the earthquakes occurred in Greece. It seems that the stress drops computed by using Brune's model are an average estimate and do not reflect to some seismotectonic characteristics of the focal region

IDARC version 3.0 : A program for the inelastic damage analysis of reinforced concrete structures

This report summarizes the significant modeling and program enhancements to the computer coe, IDARC (see Technical Report NCEER-87-0008) for inelastic damage analysis of reinforced concrete frame-wall structures. The base program is capable of analyzing structures in the inelastic range subjected to combined horizontal and vertical excitations, quasi-static cyclic loading, and incrementally applied static loads.(AU)