Wood-frame Structures Research Articles

Seismic performance of light wood shear wall infilled timber frame structures with openings

To study the seismic performance of wood frame structures filled with light wood shear walls, three full-size single-layer single span wooden frame structures with infill walls were designed and manufactured. The beams and columns were connected by mortise-tenon joints, and quasi-static tests were conducted on the specimens under reversed cyclic load. The failure modes and load-displacement hysteresis performance of structures with door opening infill wall, window opening infill wall, and solid infill wall were investigated. The seismic performance was analyzed using indicators such as strength, ductility, and equivalent viscous damping ratio. The failure modes of light wood frame filling walls were the tearing of sheathing panel and the failure of nail connections. The filled wall with the opening initially exhibited inclined cracks at the corner of the opening, and then they extended to the periphery. Compared with the solid filled wall, the positive and negative bearing capacity of the structure with door opening decreased, and that of the structure with window opening decreased also. Because the specimens with opening in the filled wall were more conducive to the deformation of the structure when the bearing capacity was not significantly reduced, the ductility of the specimen with door opening was the highest.

Rapid full-field deformation measurements of tall buildings using UAV videos and deep learning

Full-field deformation of tall buildings is informative and imperative for structural health condition assessments. This study explores the feasibility of using videos recorded by an unmanned aerial vehicle (UAV) to measure the vibration profiles of tall buildings with the aid of deep neural networks. First, a Transformer network with a self-attention mechanism is used, and its outcome is employed for the homography transformation to minimize the drifting problems induced by the UAV. Second, a boundary-aware salient object detection network is adopted to extract the boundary of the buildings in the stabilized videos for further full-field deformation measurements. The accuracy of the proposed method is experimentally validated using a wood frame structure under harmonic excitations. Under a measuring distance of approximately 4.2 m, the proposed method achieves averages of root-mean-square-errors (RMSEs) for the displacement and rotation measurements of 2.13 mm and 1.74 × 10−3 rad, respectively, as compared to that determined by an infrared light tracking system. The study further analyzes the field-test data recorded from the vibration of a 247-m tower. Under a measuring distance of about 55 m, the proposed method is comparable to the vibration measurement at a specific story and estimates the full-field deformation within the region of interest. Overall, the proposed method with rapid UAV deployment is feasible and accurate for monitoring the full-field deformation using the UAV-recorded videos.

Центр створення та розвитку стартапів Національного університету «Чернігівська політехніка»: архітектурна реновація будівлі колишнього кінотеатру «Перемога» в Чернігові

Based on modern humanistic principles of architectural and urban design and system analysis of three-dimensional solutions of the former «Peremoha» cinema in Chernihiv, the results of the study of architectural and conceptual images are presented and a project for the architectural renovation of the new building of the Center for the Creation and Development of Startups of Chernihiv Polytechnic National University is proposed. The project envisages the spatial transformation of space using a system of load-bearing wooden frame structures and innovative glass construction technologies. The designed superstructures, together with the system of terraces and balconies, will visually create a transparent space for the interior of the new building, accessible to sunlight and convenient for educational, scientific and artistic activities of students, teachers and active residents of the city.

Framework for the design of seismically isolated National Building Code of Canada Part 9 structures

In Canada, most single-family wood-frame residential structures in seismically hazardous regions are constructed according to Part 9 of Division B of the National Building Code (or similar provincial standards) using nonengineering methods. These structures are expected to perform well during an earthquake regarding life safety but may sustain severe economic losses. Seismic isolation is an emerging technology that provides excellent life safety and economic performance. While this technology has proven effective at protecting structures from earthquakes, no nonengineering methodologies exist that are compatible with Part 9 methods. This limitation produces significant testing, design, and cost barriers that restrict the application of base isolation on vulnerable Part 9 structures. To eliminate or reduce these cost barriers, a program framework was developed to perform the engineering seismic design and analysis for a base-isolated Part 9 single-family residential structure. The proposed methodology further encourages the application of seismic isolation to Part 9 structures.

Probabilistic wind uplift resistance framework for the relative evaluation of wood-frame load paths

Past failure risk analyses of wind-impacted wood-frame structural load paths have tended to consider simplified resistance models that account for a few key load path connections, in which connection capacity distributions are generally based on benchmark experimental results. However, recent post-storm reconnaissance studies have demonstrated that connections in the load path of light wood-frame structures are themselves composed of multiple elements with many configurations and possible failure modes. This study presents a flexible approach for modeling wind uplift resistance in wood-frame load paths that includes a more exhaustive set of potential failure points yet is computationally efficient and readily adaptable to various load paths composed of different assemblages of structural members and connections. In this framework, ultimate capacities of connections and wood members are either based on design equations provided in the National Design Specification for Wood Construction or another applicable standard or computed from a comparable mechanics-based model. Analytical capacity estimates for roof sheathing, roof-to-wall connections, and wall-to-slab-foundation connections accord well with the range of published experimental results for these connections. Capacities of connections that act in parallel are summed to transform the load path into an analogous load chain of series components. System-level wind uplift resistance, defined by the weakest component in series, is evaluated by Monte Carlo simulation. By providing a more complete description of resistance than previous simplified models have done while avoiding the expense of a detailed finite-element or other solid mechanics model, the method proposed here holds promise as a rapid, consistent, and accurate way to quantify wind resistance in any arbitrary wood-frame load path, with applications including insurance risk analysis, hybrid data science frameworks utilizing post-storm reconnaissance data, and estimation of hazard intensity from structural damage observations.

Simulation calculation and analysis of building energy consumption of multi-story glued laminated timber structures

As the only renewable building material, wood has a strong carbon sequestration effect. Thus, timber structures have the natural advantages of saving energy and reducing emissions. Currently, the research objects of building energy consumption are rarely timber structures. To further control the operational energy consumption of timber structures, this paper takes six-story glued laminated timber beam-column frame and light wood-frame shear wall structures as the research objects. Building energy consumption research is conducted through testing the heat transfer coefficient of the envelope structure, air circulation ratio, and Building Information Modeling (BIM) technology on-site. The results show that the energy consumption of the building is consistent with the current energy consumption of small- and medium-sized office buildings, and the heat gain and loss of the building are mainly due to solar radiation and heat conduction of the envelope, respectively. The airtightness of the building has the greatest influence on the energy consumption of the building, and the type of building structure and window-to-wall ratio have little influence on the energy consumption of the building.

Personalized Vulnerability Assessment of Customized Low-Rise Wood-Frame Residential Structures under Hurricane Wind Loads: A Flexible Scenario-Based Simulation Approach

Hurricanes are one of the costliest and deadliest weather and climate disasters that impact the United States, largely affecting the residential sector. Residential structures are essential for the health and safety of the community during a hurricane event. However, homeowners typically have to rely on general information and instructions to understand their level of risks. The knowledge of structural vulnerability to hurricanes at the individual residential building level is often limited, which hinders personalized disaster preparation and mitigation decision-making. To this end, a vulnerability assessment method is proposed for individual homeowners to create customized finite-element models that quantify wind damage of low-rise wood-frame residential structures under various scenarios using ANSYS 2020 R1 parametric design language. A case study was conducted to test the proposed methodology and investigate prevailing failure modes under different structural characteristics and wind scenarios. Specifically, the impacts of roof framing features and previous exposure to environmental conditions on the potential damage of residential buildings under hurricane wind loads were studied. Analysis results, including the percentage of failed sheathing, nailed connections and framing members, are used to inform personalized mitigation recommendations. The proposed customized vulnerability assessment may increase homeowners’ situational awareness of disasters and promote rational retrofitting decisions.

Comparative analysis of mechanical properties for wood frame and reinforced concrete frame based on deformation energy decomposition method

As a typical orthotropic material, the mechanical properties of wood in the parallel and perpendicular-to-grain directions are very different. Based on mathematical orthogonality, mechanical force balance condition, and energy comparability, the deformation energy decomposition method of planar wood element is proposed, and then the quantitative and visual analysis of the basic deformation performance of wood structure is realized. The basic deformation performance of wood structure and isotropic structure is analyzed using the deformation energy decomposition method, and the seismic performance of wood frame structure and concrete frame structure is compared. The results show that the lateral resistance and beam ductility of wood frame are greater than those of concrete frame under seismic load. However, the reduction of deformation energy proportion of wood frame beam leads to greater deformation energy of the frame column, so it is suggested to take targeted strengthening measures to the bottom of the wood frame column and the joint area.

Reassessing the Proportional System of Joseon Era Wooden Architecture: The Bracket Arm Length and Width as a Standard Modular Method

Previous research has agreed that standard modular methods in Song Yingzao Fashi and Qing Gongcheng Zuofa were not applied to Korean wooden architecture. This study notes the size of bracket arms as a standard modular method by investigating the proportion systems of Sungnyemun, Paldalmun, and Heunginjimun Gates, the official government buildings of the Joseon Dynasty. The purlin direction bracket arms in the intercolumnar bracket sets apply a proportional system in the ratio of a regular integer relationship to the front and side facades and building height. Challenging current assumptions, the application of the bracket arm width as a modular rule is divided into more subdivided values than the measurement units. A particularly important finding is that, unlike the height of the bracket arms, the width and length of the brackets are standard members that determine the height of the side facades. This is very similar to the official government building styles in the Song and Qing Dynasties, premodern China. Therefore, this study is meaningful in reassessing wooden frame structures of the Joseon era, deriving parametric measuring rules universally applied in East Asia to provide basic data useful for heritage conservation.

Machine Learning-Based Seismic Damage Assessment of Residential Buildings Considering Multiple Earthquake and Structure Uncertainties

Wood-frame structures are used in almost 90% of residential buildings in the United States. It is thus imperative to rapidly and accurately assess the damage of wood-frame structures in the wake of an earthquake event. This study aims to develop a machine-learning-based seismic classifier for a portfolio of 6,113 wood-frame structures near the New Madrid Seismic Zone (NMSZ) in which synthesized ground motions are adopted to characterize potential earthquakes. This seismic classifier, based on a multilayer perceptron (MLP), is compared with existing fragility curves developed for the same wood-frame buildings near the NMSZ. This comparative study indicates that the MLP seismic classifier and fragility curves perform equally well when predicting minor damage. However, the MLP classifier is more accurate than the fragility curves in prediction of moderate and severe damage. Compared with the existing fragility curves with earthquake intensity measures as inputs, machine-learning-based seismic classifiers can incorporate multiple parameters of earthquakes and structures as input features, thus providing a promising tool for accurate seismic damage assessment in a portfolio scale. Once trained, the MLP classifier can predict damage classes of the 6,113 structures within 0.07 s on a general-purpose computer.

EXPERIMENTAL AND THEORETICAL STUDIES OF DYNAMIC CHARACTERISTICS OF WOODEN FRAME BUILDINGS

The research carried out in this paper is reduced to studying the design features of wooden frame structures and analyzing the nature and degree of influence of individual structural elements on the work of the frame as a whole based on a comparison of experimental and theoretical data. The results of the studies with the evaluation of natural oscillations are the basis for the correct modeling of structural systems when performing static and dynamic calculations.

Development of a high-performance building material using wood-based corrugated panels manufactured via cold-forming technique

A wood-based sandwich panel with a corrugated core was developed as a building material. A matched-die mold manufactured from commercial plywood was used to fabricate the corrugated panels through a cold-forming process. A cold-setting resin was applied on southern yellow pine (Pinus spp.) veneers with an average thickness of 4 mm, and four plies of them were formed into a corrugated geometry using a wooden mold. When the resin was cured, the corrugated panel of veneers retained the corrugated shape after load removal. Facesheets of the sandwich structures were fabricated using three plies of the same veneers. To evaluate the effect of this corrugated geometry on the structural performance, the same veneers — regarding number, thickness, and orientation — used for the sandwich panel were adopted to fabricate laminated flat panels. Both sandwich and laminated flat panels were submitted to a four-point bending test. The results confirmed the sandwich effect, i.e. a 1741% increase in the bending stiffness of sandwich panels compared to that of laminated flat panels. Sandwich panels developed in this study were compared to Structural Insulated Panels (SIPs), wood-framed structures known as stud walls, and sandwich panels produced using a hot-pressing technique. The cold-formed sandwich panels had higher structural performance than commercial building materials.

大斗肘木・頭貫・三本の丸柱で構成された伝統的木造架構の復元力特性と各構造要素で評価されたモーメント抵抗性能に関する実験的研究

To clarify the influence of the head tie-beams on the restoring force of the traditional wooden frame structure, static loading tests were conducted on the model specimens with four different kinds of head tie-beam specifications subjected to the two different stages of dead loads. It was clarified that the existence of the head tie-beam greatly contributed to the performance of the specimens regardless of the specifications of the head tie-beams. Ancient specification head tie-beam showed an eccentric moment-resisting performance depending on the opening angle between column and beam. Other head tie-beams, however, had no opening angle dependency.

The Potential of Small Wooden-Frame Building in Aging Japan

Wooden-frame structures, with the capacity for continuous renewal, are key resources for urban regeneration and so comprise one of the most sustainable construction methods. This was true in the past for Japan, but following World War II, wooden-frame structures were demolished and replaced at a rapid pace. However, today, with Japan’s aging and dwindling population, the growing number of abandoned houses has become a socio-economic issue. In response to this crisis, local initiatives have been established to address this problem. Some novel design and management practices have arisen to restore the value of excess wooden-framed buildings. The purpose of this paper is to discuss the current design and renovation practices of vacant wooden-frame buildings in Japan, as well as to evaluate these practices in light of a sustainable future, by approaching this issue from the perspective of architects and designers and investigating their roles in these processes. The paper starts with the evolution of this building type from the past to the present. Data from in-depth interviews with specialists in wooden-frame construction as well as architects who are involved in the renovation of postwar timber dwellings are gathered and discussed. The emphasis here is on the expertise these specialists and architects have in successful cases of design and space management, as well as the incorporation of those buildings into the local community. Our case studies are located in different urban contexts; a regional city, a peripheral area of Tokyo, and central Tokyo. The findings highlight the crucial role of architects who mediate between benefits and drawbacks of current rehabilitation efforts, which are nevertheless still outnumbered by abandoned houses. Nonetheless, these experiences are crucial and valuable for the long-term viability of this building type in Japan.

Drift‐ and energy‐based seismic performance assessment of retrofitted wood frame shear wall buildings: Shake table tests

AbstractIn 2004, the Province of British Columbia (BC) announced a multi‐year $1.5 billion seismic retrofit program for the province's 750 at‐risk public schools. The purpose of this program was to quantify the seismic risk of the province's public‐school buildings and to expedite the seismic upgrading of the most at‐risk schools. In order to provide a safe and cost‐effective implementation of this program, the Engineers and Geoscientists BC, in collaboration with the University of British Columbia, has developed a performance‐based probabilistic method and guidelines for the seismic risk assessment and retrofit of low‐rise buildings. As part of this initiative, a number of laboratory experiments have been conducted to provide data that would support the recommendations provided in the guidelines. The laboratory experiments included several full‐scale shake table tests of wood frame systems. The specimens were subjected to sequences of earthquake motions to simulate their performance under main shock‐aftershocks. This paper presents details of seven of the experiment and wood‐frame buildings considered. A detailed discussion of the results of the analyses of the shake table tests data, and performance assessment using drift‐ and energy‐based damage indices is presented. This study highlights the importance of considering the effects of subduction earthquake and mainshock‐aftershock sequences for design and retrofit of wood frame structures.

Influence of the shives orientation on selected hygro-thermal properties of hemp-magnesium composite

Magnesium binder is an alternative to lime binder in the technology of hemp-based composites. The advantage of using this binder is an increase in mechanical strength compared to those based on lime. These composites are mainly used as an insulating wall material, as a filling of a wooden frame structure. During compaction of the mixture, hemp shives tend to lay with fibers perpendicular to the compaction direction. The direction of the fibers in the shives, as well as the direction of the capillary pores affect the properties of the composite. The performance characteristics of a building partition insulated with a composite will vary depending on the direction of the shives in relation to the direction of the external factor. The outer wall is exposed to heat flow and water transport, e.g. by capillary action. The article presents the results of tests of the thermal conductivity and capillary rise of a composite densified in the direction perpendicular and parallel to the heat flux and moisture flow. Composites samples with a bulk density of about 370 kg/m3 were tested. Compaction of the mixture in the direction parallel to the heat flow decreased the thermal conductivity. Due to the reduced value of the thermal conductivity of the composite compacted parallel to the heat flux, such a technique can be used in prefabrication, e.g. in the production of wall blocks. This direction of compaction - perpendicular to the wall surface, and thus to the direction of capillary rise, also reduced the amount of uptaken up water and changed the course of water rising over time.

WOOD STRUCTURE SYSTEM in TRADITIONAL BANJAR HOUSES in INDONESIA

Wood, which is a sustainable material, is widely used for various purposes, including for buildings. The main part of the wooden building lies in the main frame. Wood frame technology is developing quite rapidly, which is generally centered on technology from the Western world. The wood frame technology for traditional houses in Indonesia is unique, which is generally adapted to local conditions, including traditional Banjar houses. Research on traditional Banjar houses has not yet reached an adequate in-depth study of the wooden frame, even though it is unique and responsive to swampland conditions and the local environment. The wooden frame structure and construction system of traditional Banjar houses, apart from adding to the global vocabulary of wooden frames, can also be used as an alternative to wooden frames for conventional buildings. Therefore, this research is important to be carried out. This research was conducted by first taking an inventory of the structural and construction systems of several samples of traditional Banjarese houses, to be analyzed in order to obtain the formulation of the structural and construction system. The existing data and formulations will be combined with the structure and foundation construction that has been obtained in previous studies. A qualitative analysis was also carried out on the obtained formulas to provide an understanding of the forces acting on them and the reactions of the elements and their connections. The method is carried out through secondary data and direct data collection in the field, where the data obtained are compiled and analyzed with a matrix to get the level of regularity of the structure and construction system. The structural and construction systems that have been formulated will be analyzed qualitatively by their actions and reactions in the context of the forces acting on them. It was found that the wooden structure system in a traditional Banjar house consists of 17 structural elements, of which 5 have a major role in the structural system and have unique characteristics compared to other conventional and traditional systems. These structural elements form a solid wooden structural system which is proven by the survival of traditional Banjar houses to this day.

Development of Resistance Sintering Furnace for Heat Treatment of 22MnB5

This paper presents the development of resistance heating furnace based on the direct electrical conduction method that can perform with lower energy. Based on the concept of resistance welding, resistance heating furnace was developed for heat treatment of 22MnB5 Boron steel with the aim to change the microstructure from pearlite to austenite phases before quenched into martensite phase. The main component for this machine consisted of transformer, copper electrodes, copper cable coil and wood frame structure. The design of the machine resembled resistance welding with upper and lower electrodes were assembled together mounted by the wood frame. The heating energy collected from the electrical current that flow through cooper cable that rolled through toroidal transformer. The result shows that the machine capable to heat the 22MnB5 Boron steelwith maximum temperature of 721.2°C. However, the machine demonstrates overheat after 7 minutes due to the insulation burn of cooper cable. Further improvement of cooling system and copper insulation need to be addressed to prolong the heating operation.

Integrating Virtual Reality and interactive game for learning structures in architecture: the case of ancient Chinese dougong cognition

PurposeAncient Chinese architecture is famous for its wooden frame structure and unique position in world architecture history. As numerous types of components and complex combinations exist, the overall structural system and how they are interlocked have always been crucial but challenging parts of the study. Students find it hard to understand and remember the concepts using traditional 2D paper media, making such knowledge unattractive to pass on to the new generation. To overcome the challenges, this research aims to examine the effect of combining Virtual Reality (VR) with digital interaction games in learning structural characteristics (dougong) of ancient Chinese architecture.Design/methodology/approachThis research develops an interactive cognitive system in the VR environment based on constructivist theory to improve the learning approach of ancient Chinese architecture. Applying an experimental procedure, the feedback of an experimental group using the VR cognition system and a control group using traditional learning 2D media are collected to examine the differences in learning effectiveness and user experience.FindingsThis study develops an interactive cognitive system to aid in learning the structural system of ancient Chinese architecture. The results indicate that integrating VR and interactive learning games can increase students' positive attitudes and learning effectiveness towards ancient Chinese architecture.Originality/valueThis study integrates VR technology and interactive games to improve the learning approach. It examines the effect of applying the concept of human–computer interaction in learning ancient Chinese buildings. The concept of designing the interactive cognitive system is expected to guide students gradually to be the main body of learning and stimulate their learning enthusiasm and motivation.

Diversity and Variation in China's Yao Ancient Wood Frame Structures Through Genetic Algorithms

This study, focusing on the China's Yao minority community, investigates the feasibility to create a generative computational method to replicate the diversity of the existing Yao traditional wood buildings, addressing the critical issues currently facing computational design methods, in the attempt to adapt genetic-generative algorithms to the study of local ancient architecture. The project develops a computational tool to generate a network of three-dimensional prototypes, or building structures, derived from traditional wood frame village houses. It studies possible housing structures that illustrate some of the key working methods available in digital systems such as ‘generating' and ‘compositing' taking as a starting point computational strategies oriented towards geometry and where a set of local variables play a decisive role: available local technologies, use of raw materials, and the dimensioning of timber components based on data collected from Yao architecture.