Author: Bruce Lindsay DeamPublisher:
ISBN:
Category : Earthquake resistant design
Languages : en
Pages : 218
Book Description
The Seismic Design and Behaviour of Multi-storey Plywood Sheathed Timber Framed Shearwalls
Author: Bruce Lindsay DeamPublisher:
ISBN:
Category : Earthquake resistant design
Languages : en
Pages : 218
Book Description
The Seismic Design and Behaviour of Multi-storey Plywood Sheathed Timber Framed Shearwalls
Author: Bruce Lindsay DeamPublisher:
ISBN:
Category : Earthquake resistant design
Languages : en
Pages : 218
Book Description
Displacement-based seismic design for multi-storey cross laminated timber buildings
Author: Hummel, JohannesPublisher: kassel university press GmbH
ISBN: 3737602883
Category :
Languages : en
Pages : 224
Book Description
Key Terms: cross laminated timber, displacement-based seismic design, time history analysis, multi-storey timber structures, hysteretic behaviour
Study of Deflection of Single and Multi-Storey Light Frame Wood Shear Walls
Author: Mohammad Mehdi BagheriPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The behavior of wood shear walls has been the focus of researchers and engineers for many years due to their availability in the North American construction landscape. A review of the established literature showed that most of the research have focused on the shear wall behavior as a whole with no investigation specifically targeting the individual components of its deflection. Also, little to no attention has been given to the investigation of the cumulative effects especially when the out-of-plane diaphragm stiffness is considered. The current study aims at investigating the effects of construction details variation on the behavior of the shear walls and evaluating whether the current deflection equation, as per wood design standard (CSA 2014) can adequately predict the overall wall stiffness. A total of 27 full-scale single-storey walls, with different construction details and aspect ratios, were tested under either static or monotonic (as both are the same) loading. The parameters that were varied in the testing were the stud size and spacing, nail diameter and spacing, sheathing panel type and thickness and hold-down anchoring system/type. For the two-storey walls, two different loading cases were considered, namely where the load was applied at the top or bottom storey only. The results showed that the strength and stiffness correlated almost directly to the inverse of the wall aspect ratio. There was no clear trend when considering the effect of the walls' aspect ratios on ductility. Unexpectedly, walls with aspect ratios not permitted according to the wood design standard (4:1 and 6:1) followed similar strength and stiffness trends and had sufficient ductility ratios as those with smaller aspect ratios. This observation explains in part some of the discrepancies found between engineering calculations and behavior of actual building with light frame wood shear walls. Significant discrepancies were found when comparing the various deflection constituent with those estimated using the design expression. Adding more end studs and changing the size of the studs had no significant effect on the overall wall capacity and little effect on its stiffness. Reducing the stud spacing had, as expected, no effect on the wall capacity; however, the results showed that the bending stiffness was affected by the overall number of studs in the wall and not solely by the end studs. Shear walls sheathed with plywood panels exhibits slightly higher peak load and initial stiffness than those with OSB, which was mainly attributed to the greater panel thickness, and possibly density, of the plywood. Both sheathing types provided similar levels of ductility, as expected. Thicker sheathing increased the capacity and stiffness of the wall with no significant change observed in ductility ratio. The wall strength was significantly affected by the nail diameter and nail spacing, but no difference was observed when the nail edge/end distance was increased. The results also showed that discrete hold-down system behaved in a non-linear manner with a significantly greater initial stiffness than that assumed in design. The study also showed that having continuous hold-down connections has a positive effect on the capacity, stiffness and ductility of the wall when compared with discrete hold-downs. Having no hold-down adversely affects the wall capacity and stiffness, but did not affect the ductility of the wall. For the two-storey walls, the deflection estimated based on the cumulative effect assumption showed slight differences when compared with that observed in the experimental study. It was observed that the majority of the cumulative effect stems from the rigid body rotation due to deformation in the hold-down devices. A Computer shear wall model (through SAP2000) was developed using linear "frame" and "membrane" elements for the framing and sheathing members, respectively, whereas the sheathing to framing nails and hold-down were modeled using nonlinear springs. It was found that the model was capable of predicting the peak load, ultimate deflection and yield loads with reasonable accuracy, but overestimated the initial stiffness and ductility of the walls. In general, when the force-displacement curves were compared it was evident that the model was capable of predicting the wall behaviour with reasonable accuracy. When investigating the cumulative effects using the model, the results clearly showed that the assumption of cumulative effects due to rigid body rotation is valid for stacked shearwalls with no consideration for the floor diaphragm. The effect of the diaphragm on the behavior of the shear walls, in particular its out-of-plane rigidity was simulated by modeling the floors as beam. The out of plane stiffness of the shear walls was investigated for idealized (infinitely stiff or flexible) as well as "realistic". The results showed reductions in the shearwall deflection in the magnitude of approximately 80% considering the out of plane rigidity of the diaphragm. It was also concluded that considering conservative estimates of out of plane stiffness might lead to a very significant reduction in deflection and that assuming the floor diaphragm to be infinitely rigid out of plan seems reasonable. For diaphragms supported on multiple panels further reduction in the deflection was observed. More work, particularly at the experimental level, is needed to verify the finding obtained in the numerical investigation related to the effect of out of plane diaphragm stiffness.
Seismic Performance of Multi-storey Structures Designed with Cold-formed Steel Wood Sheathed Shear Walls
Author: Denise MorelloTimber Engineering
Author: Sven ThelanderssonPublisher: John Wiley & Sons
ISBN: 9780470844694
Category : Technology & Engineering
Languages : en
Pages : 460
Book Description
Timber construction is one of the most prevalent methods of constructing buildings in North America and an increasingly significant method of construction in Europe and the rest of the world. Timber Engineering deals not only with the structural aspects of timber construction, structural components, joints and systems based on solid timber and engineered wood products, but also material behaviour and properties on a wood element level. Produced by internationally renowned experts in the field, this book represents the state of the art in research on the understanding of the material behaviour of solid wood and engineered wood products. There is no comparable compendium currently available on the topic - the subjects represented include the most recent phenomena of timber engineering and the newest development of practice-related research. Grouped into three different sections, 'Basic properties of wood-based structural elements', 'Design aspects on timber structures' and 'Joints and structural assemblies', this book focuses on key issues in the understanding of: timber as a modern engineered construction material with controlled and documented properties the background for design of structural systems based on timber and engineered wood products the background for structural design of joints in structural timber systems Furthermore, this invaluable book contains advanced teaching material for all technical schools and universities involved in timber engineering. It also provides an essential resource for timber engineering students and researchers, as well as practicing structural and civil engineers.
Development of Seismic Design Provisions for Steel Sheathed Shear Walls
Author: Nisreen BalhSeismic Design of Buildings to Eurocode 8
Author: Ahmed ElghazouliPublisher: CRC Press
ISBN: 1498751601
Category : Technology & Engineering
Languages : en
Pages : 383
Book Description
This book focuses on the seismic design of building structures and their foundations to Eurocode 8. It covers the principles of seismic design in a clear but brief manner and then links these concepts to the provisions of Eurocode 8. It addresses the fundamental concepts related to seismic hazard, ground motion models, basic dynamics, seismic analysis, siting considerations, structural layout, and design philosophies, then leads to the specifics of Eurocode 8. Code procedures are applied with the aid of walk-through design examples which, where possible, deal with a common case study in most chapters. As well as an update throughout, this second edition incorporates three new and topical chapters dedicated to specific seismic design aspects of timber buildings and masonry structures, as well as base-isolation and supplemental damping. There is renewed interest in the use of sustainable timber buildings, and masonry structures still represent a popular choice in many areas. Moreover, seismic isolation and supplemental damping can offer low-damage solutions which are being increasingly considered in practice. The book stems primarily from practical short courses on seismic design which have been run over a number of years and through the development Eurocode 8. The contributors to this book are either specialist academics with significant consulting experience in seismic design, or leading practitioners who are actively engaged in large projects in seismic areas. This experience has provided significant insight into important areas in which guidance is required.
Quantifying the Seismic Response of Light-frame Shear Walls with Adhesive Sheathing Concerns
Author: Mona Karim ZadehPublisher:
ISBN:
Category : Earthquake engineering
Languages : en
Pages :
Book Description
The seismic behavior of shear walls is inevitably associated with the connectors' characteristics. While historic shear wall studies have focused on the influence of the nail connections between the sheathing and the framing, little has been done to investigate the potential advantages of using adhesives to attach the wood structural panel sheathing to the framing in wood light-frame construction. The advantages of high strength and stiffness have been recognized for improved performance in high wind events, but a total ban on the use of adhesives to attach sheathing in light-frame shear walls was imposed by the building code for regions with high seismic risk due to the same two characteristics of walls utilizing adhesives. Therefore, the seismic design parameters and the reliability of wood shear walls using adhesive connections is not explicitly known. A better understanding of the seismic behavior of timber shear walls using adhesive connections are necessary in order to modify existing design codes to allow adhesives to be used in light-frame shear walls in high-seismic risk regions. Historic R-values lack the sufficient rational basis that accounts for the effect of ground shaking on that particular system. This research used the FEMA P-695 procedure to develop seismic performance parameters for timber shear walls utilizing adhesives to attach the sheathing. The hysteresis properties of single adhesive connector that was six inches long, called DF0744-16, were obtained from available cyclic test data from a study conducted by Misner (2014). Archetype models utilizing high aspect ratio adhesive shear walls were developed based on the hysteresis parameters of adhesive shear walls. The uncertainties related to the seismic performance of archetype configurations, subjected to ground shaking, was investigated though the collapse probability process and the nonlinear response characteristics was quantified. This study of wood light-frame walls with adhesive connectors determined that a response modification factor of 2 was sufficient for most one- and two-story residential configurations.
Author: Denise Morello