Download or read book Development and Assessment of Wood Light frame Unibody Structures for Enhanced Seismic Performance written by Cristian Enmanuel Acevedo and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Past earthquakes have shown wood light-frame structures in the United States provide adequate collapse safety, but they can get severely damaged in the process. This is in part the result of building codes allowing the structure to undergo large displacements to achieve ductile behavior, by using response modification factors (R) as high as 6.5. In the US alone, more than 90 percent of single-family and multi-family residences have been constructed out of wood over the last decade, with 50 percent of the population susceptible to damaging earthquakes. Therefore, it is crucial to develop new cost effective design methodologies that can significantly reduce the risk of damage and resulting displacement of residents. The objective of this research is to demonstrate that enhancing the strength and particularly the stiffness of the light-frame residential buildings by engaging the architectural components leads to dramatically better performance. This new methodology is known as ``Unibody'' construction method. By using cost effective off-the-shelf connectors such as construction adhesives, stronger lag screws and hold-downs, the lateral stiffness of a unibody interior walls can be up to 2.6 times larger than that of conventional interior wall with hold-downs. Similarly, the lateral stiffness of a unibody exterior wall can be 3.7 times larger than that of a conventional exterior wall with hold-downs. On the other hand, the lateral strength can be 1.5 to 3 times larger than the conventional walls. Large scale quasi-static tests of four full-scale unibody room specimens were conducted and demonstrated improved performance resulting in high strength and stiffness, corroborating previous work from other researchers. In addition, these tests assessed the collapse performance by loading the structures to approximately 10 percent drift with residual strengths that were on average approximately 30 percent of the maximum strength. To further validate the proof of concept, full-scale shake table tests on a full-scale two-story unibody house were conducted and confirmed the same improved behavior seen in quasi-static tests. The tests also revealed that with careful attention to tie down detailing and contribution of transverse walls, the unibody structure can drift as much as 25 percent drift while maintaining a residual strength approximately 20 percent of the maximum strength. All tests showed ease of constructibility by professional contractors. Numerical finite element models were successfully calibrated and validated to capture the response of cyclic and dynamic tests of the unibody specimens. Modeling recommendation are provided using nonlinear hysteretic models. Using the calibrated models, general equations and adjustment factors were developed to account for wall length, wall end-returns, and perforation factors (i.e., door and window openings). Current building codes and standards do not allow the use of adhesives or architectural components as part of the lateral resisting system. To help demonstrate the benefits and overcome restrictions to utilizing these materials, design procedures were developed and comparative analyses with conventional construction were performed. Archetype building models were desgined using the conventional and unibody design procedures. In addition, nonlinear numerical models were created in OpenSees to compare the performance of conventional and unibody construction and evaluate the proposed design procedure. An R of 1.5 was used for the unibody design and an R of 6.5 for the conventional design. The archetype building models were evaluated using nonlinear dynamic analyses. The maximum mean story drift from the design level earthquake (10 percent in 50 years intensity) was compared between the unibody and the conventional structure. The unibody archetype building models experienced drifts that were on average less than 0.15 percent, while the conventional design sustained drifts that were on average 0.5 percent. The latter is larger than the median drift value of 0.2 percent for initiation of damage in gypsum walls. The results showed the unibody archetypes were essentially damage free at the design level earthquake based on the design procedure. In addition, the performance of a hybrid unibody structure was evaluated. The hybrid unibody is conventional wood shear with sheathing attached to wood framing with construction adhesive in addition to mechanical fasteners. This enhancement is done to the shear walls only. The hybrid unibody structure, on average, saw drift levels of about 0.30 percent when subjected to the to the design level ground montions, with is about 1.8 times less than the drifts seen for the conventional structure. Finally, the additional cost to implement the unibody construction was also quantified. On average, the additional cost to implement a unibody structure is about 2 percent of the total construction cost of a conventional structure. This value is 2.5 times smaller than minimum deductible of 5 percent required for residential earthquake insurance in California. These initial estimates were developed for single structures and can be further reduced if mass scale production is considered. In addition, a loss assessment study to compare the conventional and unibody construction was also performed. It was found that the loss ratio (which is the repair cost over the replacement cost of the building) for a unibody structure was on average about 7 times smaller than that of a conventional structure. The hybrid unibody structure had on average, a loss ratio that was 1.8 times smaller than that of the conventional structure. The design recommendations and the cost studies were done to provide practicing engineers with the tools to successfully implement the unibody method in new construction.
Download or read book Numerical Performance Evaluation of the Wooden Frame Structures with Adhesive Applied Connection Under Wind and Seismic Loading written by Sharthak Bhandary and published by . This book was released on 2020 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the research is divided into two folds. The first objective is to study the state-of-the-art modeling method for the wooden frame construction, while the second objective is to evaluate the performance of a wooden frame structure with construction adhesives under hazardous loading conditions using the selected numerical modeling method. The numerical modeling tools were classified under academic and commercial categories based on the purpose of their development. Both academic and commercial tools were further classified based on model types of the structural systems (i.e., shear walls and three-dimensional (3D) buildings) and the applied loads (i.e., wind loading and seismic loading). Among different commercial tools studied, SAP2000 developed by the Computer and Structures, Inc., Berkeley, USA, was selected for modeling the wooden frame structures in the second part of this study. Specifically, the use of the non-linear link element available in SAP2000 to model wood structure connections was adopted in several studies, and its feasibility to capture non-linear wood structural responses when subject to wind and seismic loadings was demonstrated. Performance evaluation of the wooden frame, shear wall, and 3D building with the application of elastomeric adhesives under different loading conditions was carried out. The experimental force-displacement responses of the adhesive and nail connections were used to define the link element behavior in the models. The validation of all three models was first done by comparing the link responses obtained from the model with the experimental data. Also, the 3D building model was validated by the symmetrical structural responses, including reactions, stress distribution, and roof deformations. Compared to the respective model with nail connections, the frame model with adhesive connections shows higher restoring force against the applied displacement, greater shear force and bending moment; the shear wall model’s restoring force is increased by 1.5 times and its effective stiffness increased by 4 times; the building model with the adhesive roof connections resists approximately 3 times more uplift pressure before roof failure.
Download or read book Full Scale Testing Modelling of Light Frame Timber Buildings written by Phillip Paevere and published by LAP Lambert Academic Publishing. This book was released on 2009 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: The differing needs and expectations of building owners, users and society are driving a change towards a technology-intensive, performance-based approach to the design and evaluation of light- frame structures. A critical underlying assumption of the performance-based philosophy is that performance can be predicted with reasonable accuracy and consistency. Development of improved performance prediction technologies, for light- frame structures, requires a detailed understanding of the structural behaviour of light-frame buildings, as well as the environmental loadings to which they are subjected during their lifetime. Full-scale structural testing in the laboratory, combined with analytical modelling, are essential in obtaining this understanding. This work presents the results of detailed experimental and analytical investigations into the performance of light-frame structures under lateral loading.
Download or read book Wood Materials and Shearwalls of Older Light frame Residential Structures written by Cameron T. Carroll and published by . This book was released on 2006 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light-frame construction practices and materials have changed greatly over the past 100 years. Contemporary research has focused on modern construction; thus, we know a great deal about the behavior of modern lightframe buildings under lateral forces. However, there are many light-frame buildings that were built prior to the introduction of modern building codes and material standards, and these buildings are still in service. The material and performance databases for these older structures are limited, so risk assessment and condition assessment are challenged for seismic or wind events. The project objective is to establish a basis for probabilistic assessment of the seismic performance of older construction by examining the performance of shearwalls, connections, and wood materials from older light-frame buildings Nineteen structures built between 1900 and 1970, scheduled for demolition, were sampled for material and connection tests as well as full-size shearwall tests. The scope of tests for each source structure was based on the availability of full-size shearwalls and the type of sheathing material used in the structure. Two exterior sheathing types were found in the source structures, horizontal plank sheathing and plywood. Wood lath-and-plaster was the characteristic interior wall covering in buildings of this era. Specific gravity was determined, and embedment tests were performed on the wood framing and sheathing materials. Bending-yield tests were performed on the sheathing nails (typically 0.113 by 2.5- in.), and lateral single-nail connection tests were performed on extracted connections. Full-scale shearwall racking tests were done both monotonically and cyclically using the basic CUREE loading protocol. The average specific gravity of the wood materials was 0.46. The material extracted from the source structures had an embedment strength that was statistically similar to the National Design Specifications (NDS) table value for a specific gravity of 0.46 (4.0 ksi). The results of the nail bending-yield test showed no significant change over time. Nails had average bending-yield strength of 97.3 ksi, which is similar to the NDS stated value of 100 ksi. In general, the connection tests showed agreement with the European Yield Model (EYM) equations for connection strength. The full-size shearwall capacities were in agreement with known values for walls with each type of sheathing. Based on the limited testing done in this study, no adverse effects due to age and service life were observed. The materials and assemblies performed according to modern standards for new construction. Insect damage and fungi deterioration were present in many of the structures, and because these conditions were avoided as much as possible, no inferences are made regarding the effects of insect and fungi damage on lateral shear strength. These tests show that a structure built in the early 1900?s will meet modern design expectations as long as the material has been kept dry and free of damage due to insects. The principal threats to hazard performance observed during this study were the construction practices in the early twentieth century. Most of the source structures had no anchorage to the foundation, shearwalls were connected to roof diaphragms with limited toe nail connections, most structures were sheathed with horizontal planks, and many of the source structures had few walls that met the modern prescribed aspect ratio for structural shearwalls of 2:1 for full table design capacity. The results of this research can be integrated with the Federal Emergency Management Administration (FEMA) document on seismic rehabilitation for buildings.
Download or read book Fragility Methodology for Performance based Engineering of Wood frame Residential Construction written by Yue Li and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hurricanes and earthquakes have caused extensive property damage to wood-frame residential construction in the past two decades in the United States. In order to improve residential building performance and mitigate losses from hurricane and earthquake hazards, there is an urgent need for better understanding of building performance and improvements in design and evaluation tools. In this study, a fragility analysis methodology is developed for assessing the response of light-frame wood construction exposed to extreme hurricane winds and earthquakes. The fragility is a conditional limit state probability, presented as a function of the 3-second gust wind speed (hurricanes) or spectral acceleration at the fundamental period of the building (earthquakes), leading to a relation between damage state probability and the hazard stipulated in ASCE Standard 7. A fully coupled probabilistic framework is proposed to assess reliability of the residential construction through convolution of the structural fragility model with hazard models. Finally, a comparative risk assessment addresses the similarities and differences in competing hurricane and earthquake hazards. The tools above can be used to evaluate new and existing building products, model the uncertainties that are inherent to the prediction of building performance, and manage the risk that is consequent to these uncertainties economically.
Download or read book Principles of Structural Design written by Ram S. Gupta and published by CRC Press. This book was released on 2019-06-17 with total page 599 pages. Available in PDF, EPUB and Kindle. Book excerpt: Timber, steel, and concrete are common engineering materials used in structural design. Material choice depends upon the type of structure, availability of material, and the preference of the designer. The design practices the code requirements of each material are very different. In this updated edition, the elemental designs of individual components of each material are presented, together with theory of structures essential for the design. Numerous examples of complete structural designs have been included. A comprehensive database comprising materials properties, section properties, specifications, and design aids, has been included to make this essential reading.
Download or read book Residential Open Building written by Stephen H. Kendall and published by Routledge. This book was released on 2010-04-29 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: Residential Open Building, the result of a CIB Task Group 'Open Building Implementation', provides a state-of-the-art review of open building, fundamental principles, recent developments, and international coverage of current projects on both the public and private arena. Open Building is a highly flexible and economical method of building which has far reaching advantages for urban designers, architects, contractors, developers and end users.
Download or read book Basic Guide to System Safety written by Jeffrey W. Vincoli and published by John Wiley & Sons. This book was released on 2006-03-31 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a nuts-and-bolts understanding of current system safety practices Basic Guide to System Safety is an ideal primer for practicing occupational safety and health professionals and industrial safety engineers needing a quick introductionto system safety principles. Designed to familiarize the reader with the applicationof scientific and engineering principles for the timely identification of hazards, thisbook efficiently outlines the essentials of system safety and its impact on day-to-dayoccupational safety and health. Divided into two main parts - The System Safety Program and System Safety Analysis: Techniques and Methods - this easy-to-understand book covers: System safety concepts System safety program requirements Probability theory and statistical analysis Preliminary hazard analysis Failure mode and effect analysis Hazard and Operability Studies (HAZOP) and what-if analyses The Second Edition reflects current industry practices with a new chapter on the basic concepts, utility, and function of HAZOP and what-if analyses, two analytical techniques that have been routinely and successfully used in the petrochemical industry for decades. In addition, expanded coverage on the use of the job safety analysis (JSA) adds practical examples emphasizing its value and understanding.
Download or read book Greening the Industrial Facility written by Thomas Graedel and published by Springer Science & Business Media. This book was released on 2006-04-09 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook and reference fills a critical gap in literature on the comprehensive environmental impacts of industrial organizations. Nineteen chapters examine individual industrial sectors inherent "potential to pollute." The text goes on to analyze new technologies and practices for transforming environmentally degrading effects of industry, and shows how managers can navigate these changes and move their organizations towards long-term environmental sustainability.
Download or read book Understanding Smart Sensors written by Randy Frank and published by Artech House Publishers. This book was released on 1996 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Two of the most important trends in sensor development in recent years have been advances in micromachined sensing elements of all kinds, and the increase in intelligence applied at the sensor level. This book addresses both, and provides a good overview of current technology". -- I&CS
Download or read book Primer on Seismic Isolation written by Andrew W. Taylor and published by ASCE Publications. This book was released on 2004-01-01 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This primer describes the current state of seismic isolation technology and highlights issues and concerns which are unique to the design of isolated structures. Readers will rapidly gain practical knowledge related to base isolation design from this concise book. Included are the fundamentals of seismic isolation, design of isolated structures, analysis, and testing. Provided are overviews of of the topic that are accessible not only to structural engineers who have not been formally trained in base isolation design, but also to architects and students in a first-level engineering course. This book emphasizes practical issues, rather than theoretical issues, making it complementary to textbooks on earthquake engineering."--BOOK JACKET.Title Summary field provided by Blackwell North America, Inc. All Rights Reserved
Download or read book CliffsTestPrep ASVAB written by Fred N. Grayson and published by Cliffs Notes. This book was released on 2004-03-15 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: The CliffsTestPrep series offers full-length practice exams that simulate the real tests; proven test-taking strategies to increase your chances at doing well; and thorough review exercises to help fill in any knowledge gaps. See PDF example CliffsTestPrep ASVAB can help you qualify for the military. The Armed Services Vocational Aptitude Battery is an exam that presents a series of individual tests to measure various academic and vocational skills. Use this study guide to help you get started in the military career of your choice. Inside, you'll find Three full-length practice tests A diagnostic test to assess your strengths and weaknesses Practice questions, answers, and explanations in each chapter An action plan for effective preparation Subject area reviews covering all areas of the exam With practical tips on how to boost your scores on all nine sections of the ASVAB, this comprehensive guide will help you score your highest. In addition, you'll hone your knowledge of subjects such as General science, including life sciences, chemistry, physics, and earth science Basic math skills, including fractions, decimals, percents, and arithmetic operations Vocabulary, including a review of prefixes, roots, and suffixes Reading comprehension, including identification of main ideas, sequence of events, and conclusions Auto and shop information, including the basics on engines, transmissions, measuring tools, and design Advanced mathematics, including number theory, algebra, and geometry Mechanical comprehension, including fluid dynamics and mechanical motion Electronics, including electric power generation, Ohm's Law, and semiconductors Assembling objects, including puzzles and connections With guidance from the CliffsTestPrep series, you'll feel at home in any standardized-test environment!
Download or read book Advances in Performance Based Earthquake Engineering written by Michael N. Fardis and published by Springer Science & Business Media. This book was released on 2010-07-05 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Performance-based Earthquake Engineering has emerged before the turn of the century as the most important development in the field of Earthquake Engineering during the last three decades. It has since then started penetrating codes and standards on seismic assessment and retrofitting and making headway towards seismic design standards for new structures as well. The US have been a leader in Performance-based Earthquake Engineering, but also Europe is a major contributor. Two Workshops on Performance-based Earthquake Engineering, held in Bled (Slovenia) in 1997 and 2004 are considered as milestones. The ACES Workshop in Corfu (Greece) of July 2009 builds on them, attracting as contributors world-leaders in Performance-based Earthquake Engineering from North America, Europe and the Pacific rim (Japan, New Zealand, Taiwan, China). It covers the entire scope of Performance-based Earthquake Engineering: Ground motions for performance-based earthquake engineering; Methodologies for Performance-based seismic design and retrofitting; Implementation of Performance-based seismic design and retrofitting; and Advanced seismic testing for performance-based earthquake engineering. Audience: This volume will be of interest to scientists and advanced practitioners in structural earthquake engineering, geotechnical earthquake engineering, engineering seismology, and experimental dynamics.
Download or read book Post earthquake Investigation Field Guide written by Earthquake Engineering Research Institute and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Post-Earthquake Investigation Field Guide stresses advance planning. It outlines procedures that enable EERI to dispatch investigation teams quickly and effectively when the need arises. The guide also describes procedures for deciding what earthquakes will be investigated; responsibilities of project participants, formation and dispatch of investigation teams; and dissemination of the information collected. It also offers guidelines for specific data collection in the field.
Download or read book Seismic Design Methodologies for the Next Generation of Codes written by P. Fajfar and published by Routledge. This book was released on 2019-09-10 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings, arising from an international workshop, present research results and ideas on issues of importance to seismic risk reduction and the development of future seismic codes.
Download or read book Natural Catastrophe Risk Management and Modelling written by Kirsten Mitchell-Wallace and published by John Wiley & Sons. This book was released on 2017-04-24 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers both the practical and theoretical aspects of catastrophe modelling for insurance industry practitioners and public policymakers. Written by authors with both academic and industry experience it also functions as an excellent graduate-level text and overview of the field. Ours is a time of unprecedented levels of risk from both natural and anthropogenic sources. Fortunately, it is also an era of relatively inexpensive technologies for use in assessing those risks. The demand from both commercial and public interests—including (re)insurers, NGOs, global disaster management agencies, and local authorities—for sophisticated catastrophe risk assessment tools has never been greater, and contemporary catastrophe modelling satisfies that demand. Combining the latest research with detailed coverage of state-of-the-art catastrophe modelling techniques and technologies, this book delivers the knowledge needed to use, interpret, and build catastrophe models, and provides greater insight into catastrophe modelling’s enormous potential and possible limitations. The first book containing the detailed, practical knowledge needed to support practitioners as effective catastrophe risk modellers and managers Includes hazard, vulnerability and financial material to provide the only independent, comprehensive overview of the subject, accessible to students and practitioners alike Demonstrates the relevance of catastrophe models within a practical, decision-making framework and illustrates their many applications Includes contributions from many of the top names in the field, globally, from industry, academia, and government Natural Catastrophe Risk Management and Modelling: A Practitioner’s Guide is an important working resource for catastrophe modelling analysts and developers, actuaries, underwriters, and those working in compliance or regulatory functions related to catastrophe risk. It is also valuable for scientists and engineers seeking to gain greater insight into catastrophe risk management and its applications.
Download or read book Factor Four written by Ernst U.von Weizsacker and published by Routledge. This book was released on 2013-10-11 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the industrial revolution, progress has meant an increase in labour productivity. Factor Four describes a new form of progress, resource productivity, a form which meets the overriding imperative for the future (sustainability). It shows how at least four times as much wealth can be extracted from the resources we use. As the authors put it, the book is about doing more with less, but this is not the same as doing less, doing worse or doing without. In 1972, the Club of Rome published Limits to Growth, which sent shock waves around the world by arguing that we were rapidly running out of essential resources. This Report to the Club of Rome offers a solution. It lies in using resources more efficiently, in ways which can already be achieved, not at a cost, but at a profit. The book contains a wealth of examples of revolutionizing productivity, in the use of energy; from hypercars to low-energy beef; materials, from sub-surface drip irrigation to electronic books, transport, video conferencing to CyberTran, and demonstrating how much more could be generated from much less today. It explains how markets can be organized and taxes re-based to eliminate perverse incentives and reward efficiency, so wealth can grow while consumption does not. The benefits are enormous: profits will increase, pollution and waste will decrease and the quality of life will improve. Moreover, the benefits will be shared: progress will no longer depend on making ever fewer people more productive. Instead, more people and fewer resources can be employed. While for many developing countries the efficiency revolution may offer the only realistic chance of prosperity within a reasonable time span. The practical promise held out in this book is huge, but the authors show how it is up to each of us, as well as to businesses and governments, to make it happen.
