Academic literature on the topic 'Timber structures'

The objectives of this article are to seek the opportunity to enhance the local Indonesia timber material physical performances (encompassing the low-class quality of III and IV timbers with the Modulus of Elasticity (MOE) = 5,000 - 9,000 MPa) utilizing laminated composite technology to become higher-class timber quality (class II) with the Modulus of Elasticity (MOE)> 15,000 MPa so that it can be used as an alternative material for constructing the bridge mainframe structures (girder beams) especially for the Indragiri Hilir regency, Riau Province, Indonesia. This regency needs several hundred small-medium bridges for connecting 20 districts, 39 wards, and 197 villages using local materials such as local timbers. This laminating technology is not a new technology but the utilization of this technology for constructing the main bridges structures is challenging and limited to the implementation in the civil construction industrial sector. This study composed 2 types of the low-class quality (lcq) of timber materials (such as Shorea sp and Shorea peltata Sym) and 2 types of medium class-quality (mcq) ones (Dipterocarpus and Calophyllum) for constructing the main bridge structures. Based on the laboratory test results utilizing 80% of lcq materials and 20% mcq ones, these composite timber materials may increase the timbers MOE by 145% to 166% from the existing MOE value of the mcq solid timbers. Based on the simulations these laminated composites wooden bridge girders 2 x (70x20) m2, these timber materials have passed all the tests and the application of this technology may improve the lcq timber values and it could be used for an alternative material of the bridge girder's main structures.

Timber Structures Fire Resistance The topic of this contribution is an outline of the timber structures design and assessment issues related to effects of fire according to standard and alternative (fully probabilistic) methods.

Key point to development of environmentally friendly timber structures, appropriate to urban ways of living, is the development of high-rise timber buildings. Comfort properties are nowadays one of the main limitations to tall timber buildings, and an enhanced knowledge on damping phenomena is therefore required, as well as improved prediction models for damping. The aim of this work has consequently been to estimate various damping quantities in timber structures. In particular, models have been derived for predicting material damping in timber members, beams or panels, or in more complex timber structures, such as floors. Material damping is defined as damping due to intrinsic material properties, and used to be referred to as internal friction. In addition, structural damping, defined as damping due to connections and friction in-between members, has been estimated for timber floors. The thesis consists of six main parts. The first part is entitled “Contexts”, and is composed of four chapters. A general overview of the wood material and its structural use in buildings is presented in Chapter 1. Chapter 2 gives a thorough literature review on comfort properties of (timber) floors. Chapter 1 and Chapter 2 serve as justifications for the motivation of this work, expressed in Chapter 3, and the aim of the work, expressed in Chapter 4. The next part “Backgrounds” briefly describes the basic theories used along the thesis, for the analytical studies (Chapter 5), the experimental studies (Chapter 6), and the numerical studies (Chapter 7). The part “State of the art” is a general literature review on damping (Chapter 8). A particular accent is set on the derivation of various damping prediction models. The “Research” part summarizes the original research work. Chapter 9 briefly presents the background and main findings for each study, and Chapter 10 concludes and proposes suggestions for further research. The studies are detailed in four journal papers, which are integrally reported in the “Publications” part. Paper I focuses on the evaluation of material damping in timber beam specimens with dimensions typical of common timber floor structures. Using the impact test method, 11 solid wood beams and 11 glulam beams made out of Norway Spruce (Picea Abies) were subjected to flexural vibrations. The tests involved different spans and orientations. A total of 420 material damping evaluations were performed, and the results are presented as mean values for each configuration along with important statistical indicators to quantify their reliability. The consistency of the experimental method was validated with respect to repeatability and reproducibility. General trends found an increasing damping ratio for higher modes, shorter spans, and edgewise orientations. It is concluded from the results that material damping is governed by shear deformation, which can be expressed more conveniently with respect to the specific mode shape and its derivatives. Paper II deals with the prediction of material damping in Timoshenko beams. Complex elastic moduli and complex stiffness are defined to derive an analytical model that predicts the hysteretic system damping for the whole member. The prediction model comprises two parts, the first related to bending, and the second related to shear. Selected experimental damping evaluations from Paper I are used to validate the model and obtain fitted values of loss factors for two types of wood. The good agreement of the derived model with experimental data reveals an efficient approach in the prediction of material damping. In Paper III, a semi-analytical prediction model of material damping in timber panels is described. The approach is derived from the strain energy method and input is based on loss factors, which are intrinsic properties of the considered materials, together with material properties and mode shape integrals, whose calculation can easily be implemented in most finite element codes. Experimental damping evaluations of three types of timber panels are performed. These are particleboards, oriented strand board panels and structural laminated veneer panels. Fair goodness-of-fit between the experimental results and the prediction models reveals an efficient approach for the prediction of material damping in timber panels with any boundary conditions, knowing only the loss factors and the mode shapes. In Paper IV, dynamic properties of two timber floors are experimentally evaluated by impact method. Each floor uses one specified type of connectors, either screws or nails. A numerical model is developed using constrained degrees-of-freedom for the modeling of connectors. Numerical analyses have been performed, and show good agreement with experimental results. A procedure is written using the commercial finite element software Abaqus to predict material damping from a strain energy approach. Estimation of structural damping is performed as the difference between the experimentally evaluated total damping and the predicted material damping. The contribution from floor members to material damping is extensively investigated, and the needs for better prediction of damping are discussed. Specific details of some aspects of the work are included in the “Appendix” part.

Dissertação para obtenção do Grau de Mestre em Engenharia Civil – Estruturas e Geotecnia
This dissertation covers the study of historic timber roof structures in Transylvania area - Romania, the structures type, its elements and connection variety between them. Procedures to study a structure of this category are approached. It is also referred semi and non-destructive tests that can be done to better understand the present wood characteristics, and potential reparation or strengthening solutions for the structure in case it is necessary. Ultimately a case study is analyzed and some intervention solutions are proposed for a gothic structure type in the nave of Huedin Reformed church.

Increasingly complex architectural geometries present new challenges for structural engineers. Collaborative, digital workflows which integrate 3D parametric architectural models with Finite Element Modelling software grant structural engineers a higher degree of geometric versatility and influence during the preliminary design phase. Through integrated parametric design models – also labelled “co-rationalized” – structural engineers may not only easily respond to rapid model variations and unusual assemblies, but also inform the building design from inception. This thesis presents an example of a project executed in a co-rationalized manner through architectural and structural collaboration, using both digitally-integrated and analog models, for the design and construction of solid timber shells structures using Cross-Laminated Timber (CLT) panels. By exploring a co-rationalized design process, timber engineering details are identified and integrated into the architectural model, and the role of structural engineer takes an active rather than reactionary role in the preliminary design stages. The result of this process using integrated parametric models was the design, fabrication, and assembly of a folded plate wall prototype and three CLT panels with double curvature. This research demonstrates how collaboration and integrated modeling enables the realization of the architectural versatility that mass-timber has to offer, and the efficacy which co-rationalized design and integrated models can bring to orthodox and unusual structures alike. As a consequence, this research serves as a precedent for structural detailing-based generative architecture and collaborative work in the future.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

Connections and fasteners play an essential role in the determination of strength and stability, ductility and robustness, i.e., the overall behaviour of timber structures. In particular, connections subjected to static loads are to be investigated in terms of strength and stiffness, whereas the ones designed to withstand cyclic (e.g., seismic) loads need also the definition of their complete hysteretic response. This Ph.D. dissertation focuses on the behaviour of modern connections being developed and employed in timber engineering. An initial overview on mechanical connections employed in timber structures and their evolution is reported in the introductive section of this thesis. Advantages as well as critical issues of traditional connections are the motivations for the evolution and the improvements brought by innovative connections. Two different applications of innovative timber connections are analysed and hereby discussed, each one facing different issues. The first one claims to give an insight into modern screws employed in Timber-concrete composite (TCC) structures, where the major objective is to achieve maximum strength and above all stiffness. The second is directly focused on the cyclic performance of modern connections employed in Cross Laminated Timber (CLT) structures where dissipative capacity and structural damping are of utmost importance. Consequently, the present manuscript is subdivided into two main parts. The first part deals with TCC joints realized with modern screws. The key-point to guarantee adequate mechanical performance to these composite structures is the use of connectors that demonstrate sufficient shear strength and stiffness at the interface between timber beam and concrete slab independently of the presence of an intermediate layer. Modern cylindrical connectors, such as self-tapping screws, are rising interest because they combine remarkable performance, when their withdrawal capacity is exploited, and quickness of execution especially in case of onsite installation. In this paper, a theoretical approach to calculate shear strength and stiffness of TCC joints made with inclined screws is discussed and compared to current design procedures. Furthermore, a report on short-term push-out tests of TCC joints realized with inclined self-tapping screws carried out varying fastener arrangement, diameter and concrete type is given. Consequently, a comparison between the results obtained with the theoretical method and experimental tests is reported and critically discussed in terms of both strength and stiffness. The last section of the first part present the design of an innovative connector that combines the use of self-tapping screws and a glass-fibre reinforced polymer (GFRP) element as components to realize structural TCC joints. FRP is being used in civil engineering since decades, but most of these applications utilize pre-impregnated thermosetting composites, the most common of which is carbon fibre-reinforced polymer (CFRP). On the contrary, injection moulded thermoplastic materials are relatively new and lack of history of their use in civil infrastructures. The aim is to develop a connection that solves typical installation issues of inclined screws and avoids stress concentration issues that may occur in the concrete layer. Numerical simulations, carried out to design this particular joint and exploiting a hybrid approach, are described in detail. Then, results from the experimental tests conducted to investigate the behaviour of the device subjected to shear loading conditions are compared with the analytical predictions valid for inclined screws previously described. The second part of this work focuses on the developing of an innovative earthquake-resistant connections employed for CLT structures. The seismic performance of CLT buildings is mainly related to the capability of joints to perform plastic work, since timber elements have limited capability to deform inelastically. Nowadays, the use of hold-down and angle bracket connections, which were originally developed for platform-frame constructions, has been extended also to CLT buildings. Nevertheless, the dissipative capacity of light-frame buildings is mainly diffused in nailing between frames and panels while, in CLT walls, the dissipative contribution is exclusively assured by ductile joints connecting the panels. The need of more reliable connections that provides well predictable and stable hysteretic behaviour, reduced pinching phenomenon (caused by the wood embedment) and strength degradation, justifies the continuous development of “innovative” connections. In this work, a newly developed connection element that overcomes the aforementioned issues and works for both tensile or shear loads is designed and assessed, and various significant aspects are discussed. Initially, the design procedure of the connection element and preliminary experimental tests that validates the numerical predictions are illustrated. Then, improved versions of the device are illustrated and their experimental results reported with particular attention in describing their hysteretic response and coupled shear-tension strength domain. In this work, an important role is also given to the application of the capacity design criteria applied at the joint level in order to guarantee the best exploitation of the connection’s dissipative capacity. Therefore, theoretical concepts, which describe the overstrength of traditional and innovative connections, confirmed by experimental tests of the brackets anchored to a CLT panel, are also given. In the last chapter is presented a numerical model that, following a macro-element approach, reproduces the actual cyclic response of the investigated device when subjected to combined shear-tension loads. Finally, the results of Non-Linear Dynamic Analyses of a case study CLT building realized which such model are reported and the seismic capacity of the case study building is evaluated. With these two examples, this thesis aims to give an original contribution in the evaluation of performance of innovative connection systems for timber structures, combining the use of theoretical, numerical and experimental models, and highlighting the emerging differences with respect to the use of traditional fasteners and connections.
Le connessioni e gli elementi di fissaggio svolgono un ruolo essenziale nella determinazione della resistenza, stabilità e solidità, ovvero nella risposta globale delle strutture del legno. In particolare, le connessioni soggette a carichi statici devono essere studiate in termini di resistenza e rigidezza, mentre quelle progettate per resistere a carichi ciclici (ad es. sismici), necessitano anche della completa definizione della loro risposta isteretica. Questa tesi si concentra sul comportamento dei collegamenti moderni sviluppati e impiegati nell'ingegneria del legno. Una prima panoramica sulle connessioni meccaniche impiegate nelle strutture del legno e la loro evoluzione è riportata nella sezione introduttiva di questa tesi. Vantaggi e criticità delle connessioni tradizionali sono le motivazioni dell’evoluzione e dei miglioramenti prodotti dalle connessioni innovative. Vengono analizzate e discusse due diverse applicazioni di connessioni per strutture in legno, ognuna delle quali espone aspetti e problematiche diverse. Il primo afferma di dare una panoramica delle moderne viti utilizzate nelle strutture composte legno-calcestruzzo (TCC), dove l'obiettivo principale è ottenere massima resistenza e ancor più rigidezza. Il secondo, è incentrato direttamente nell’analisi delle prestazioni cicliche delle connessioni moderne utilizzate nelle strutture in CrossLam (CLT) in cui la capacità dissipativa e lo smorzamento strutturale sono della massima importanza. Di conseguenza, il presente manoscritto è suddiviso in due parti principali. La prima parte riguarda le giunzioni legno-calcestruzzo realizzate con viti moderne. Il punto chiave per garantire prestazioni meccaniche adeguate a queste strutture composite è l'utilizzo di connettori caratterizzati da un'adeguata resistenza e rigidezza tra trave di legno e soletta di calcestruzzo, indipendentemente dalla presenza di uno strato intermedio. I connettori cilindrici moderni, come le viti autofilettanti, possiedono un crescente interesse perché combinano elevate prestazioni, se è sfruttata la loro elevata capacità ad estrazione, e rapidità di esecuzione. In questo lavoro viene proposto un approccio teorico semplificato per calcolare la resistenza al taglio e la rigidezza dei giunti TCC realizzati con viti inclinate e poi confrontato con le attuali procedure di progettazione. Inoltre, viene fornito un rapporto sulle prove di push-out a breve termine di giunti TCC realizzati con viti autofilettanti inclinate, effettuate con vari tipi di fissaggio, diametro e tipo di calcestruzzo. Di conseguenza, viene anche riportato un confronto tra i risultati ottenuti con il metodo teorico e le prove sperimentali e viene discusso criticamente in termini di forza e rigidezza. L'ultima sezione della prima parte comprende la progettazione di un connettore innovativo che combina l'utilizzo di viti autofilettanti e polimero termoplastico rinforzato con fibra di vetro (GFRP) per realizzare giunti TCC strutturali. Gli FRP vengono utilizzati nell’ingegneria civile da decenni, ma la maggior parte di queste applicazioni utilizza compositi termoindurenti pre-impregnati, il più comune dei quali è il polimero rinforzato in fibra di carbonio (CFRP). Al contrario, i materiali termoplastici sono relativamente nuovi e mancano di storia nell'utilizzo nell'infrastruttura civile. Le simulazioni numeriche, effettuate per progettare questo giunto, sono descritte in dettaglio. Quindi, i risultati delle prove sperimentali condotte per esaminare il comportamento del dispositivo sottoposto a condizioni di carico di taglio sono confrontati con le previsioni analitiche descritte. La seconda parte di questo lavoro si concentra sullo sviluppo di collegamenti innovativi impiegati per le strutture in CLT. La prestazione sismica degli edifici CLT è principalmente legata alla capacità dei collegamenti di plasticizzarsi, poiché gli elementi del legno hanno una capacità limitata di deformazione inelastica. Oggi, l'utilizzo di connessioni quali hold-down e angolari, originariamente sviluppati per costruzioni tipo platform-frame, è stato esteso anche agli edifici CLT. Tuttavia, la capacità di dissipazione degli edifici a telaio è diffusa soprattutto nella connessione telaio-pannello, mentre nelle strutture in CLT il contributo dissipativo è assicurato esclusivamente da connessioni duttili che collegano i pannelli. La necessità di una connessione più affidabile che fornisca un comportamento isteretico prevedibile ed affidabile, un fenomeno ridotto di “pinching” (causato dal rifollamento del legno) e una degrado di resistenza giustifica lo sviluppo continuo di connessioni "innovative". In questo lavoro è stato progettato e valutato un elemento di connessione che sormonti i problemi sopradescritti e che lavora sia per i carichi di trazione che per taglio, e ne vengono discussi gli aspetti più significativi. Inizialmente viene illustrata la procedura di progettazione dell'elemento di connessione e dei test sperimentali preliminari che convalidano le previsioni numeriche. Successivamente vengono descritte le fasi di progettazione e test di ulteriori versioni migliorate delle staffe dissipative e sono riportati i loro risultati sperimentali facendo particolare attenzione nel descrivere la loro risposta isteretica e il dominio di resistenza tensione-taglio. Un ruolo importante in questo lavoro è dato all'applicazione dei criteri di gerarchia delle resistenze (progettazione in capacità) a livello di connessione al fine di garantire il miglior sfruttamento della capacità dissipativa della connessione. Di conseguenza, vengono forniti concetti teorici che descrivono l’applicazione di tali concetti a connessioni tradizionali e innovative, e confermate da prove sperimentali delle staffe oggetto di studio ancorate a un pannello CLT. Infine, i risultati di simulazioni numeriche dettagliate e prove cicliche quasi-statiche sono state utilizzate per sviluppare un modello di macro-elemento implementato in un codice numerico che ha permesso di determinare le prestazioni sismiche di un edificio caso studio in CLT realizzato con tali connessioni. Con questi due esempi la presente tesi mira a definire un originale procedura di valutazione delle performance delle connessioni innovative per legno, combinando l'uso di modelli teorici, numerici ed analisi sperimentali e mettendone in evidenza le differenze emergenti rispetto all'impiego di sistemi di connessioni tradizionali.

This research aims to examine the applicability of conventional inspection methods for timber structures where structures have recognised heritage value. The research seeks to understand the appropriateness of inspection methodologies typically prescribed for timber in heritage applications. A literature review of current inspection methods utilised by engineers, architects and others within the heritage structures field has been undertaken, and the appropriateness of timber structural inspection methods used in practice (destructive testing, semi-destructive testing, and non-destructive testing methods) reviewed in light of heritage aims for Australian structures, and interviews conducted with practicing industry professionals to discuss uptake of these methods in practice. A review of current literature indicates that non-destructive technologies present significant potential for further analysis of timbers in-situ without damage to the fabric itself, and represent a particular opportunity for heritage sites, as analysis can be conducted with minimal invasiveness. Interviews with practicing professionals within this industry indicates that currently, such methods have been incorporated only minimally into standard professional practice methodologies. While a lack of familiarity with many available methods is evident, the reasons behind the limited uptake are complex, including but not limited to a lack of pre-defined Australian guidelines prescribing their use, a perception of high associated costs, and an unwillingness on the part of clients to request the use of these methods. It is found that significant opportunity exists for an improvement in the uptake of non-destructive methods as preferential over semi-destructive test methods. Indicative processes of example best-practice methods incorporating non-destructive testing into a typical assessment regime are presented.

It is common practice in the analysis of structural frames, to either assume that the joints are pinned or rigid. In fact the real behaviour of a joint is neither pinned nor rigid, and lies somewhere between the pinned and rigid assumption. This is referred to as the semi-rigid behaviour. Semi-rigidity not only refers to the rotational behaviour of the joint as commonly studied, but also in axial and shear actions. The moment distribution between pinned and rigid analysis differs substantially and therefore a more accurate method of modelling the semi-rigid joint is necessary to predict the overall structure response. The level of semi-rigid behaviour varies in different joints due to the material, construction and type of connector. The degree of semi-rigidity can be determined through physical tests. The type of joint for this study is the Metal Plate Connector (MPC) for timber trusses, 6 chosen connector used in residential trusses. An extensive test program was carried out in this study. Four different types of joints of a Queen truss were tested. In addition, the effect of combined loads on the joint characteristics was investigated. The loading arrangement in the tests allowed independent control of the bending moment and axial load. A novel approach is adopted to measure displacement, using high-resolution digital photogrammetry and specially developed software. The data produced gave details of timber movement in cartesian co-ordinates and measurement of plate deformation. From these tests, semi-rigid bending moment and axial stiffness values were determined for use in the theoretical study. An attempt to measure shear stiffness is also presented. Further tests were carried out on full-scale trusses under two different load conditions. The theoretical work comprises two approaches to truss modelling. The first is an automated structural analysis program, which accounts for non-linear semirigid joint characteristics derived from the joint tests using the Foschi power function. The effects of stability and geometrical non-linearity are also implemented into the analysis. The second approach calculates truss response using Finite elements where 2-D planar elements were used to calculate the response of the truss. Parameters for the connection strength are derived from the joint tests. Moment stiffness and axial stiffness values of the connections were determined. Combined load tests showed that there is indeed a measurable effect on joint stiffness and capacity due to combined loads, some of which actually contribute to the stiffness, but also some which are detrimental. There is good correlation between the truss test results and the FE model using semi-rigid joints. However, results of the simpler non-linear frame analysis, did not compare so well, but nevertheless exhibited fundamental characteristics of the truss.

The research is aimed at developing seismic methods for the design and evaluation of the seismic vulnerability of wooden structures, using a displacement-based approach. After a brief introduction on the seismic behaviour of timber structures, the general Direct Displacement-Based Design (Direct-DBD) procedure and the state-of-the-art are presented, with clear reference to the application of the Direct-DBD method to wooden buildings. The strength of the Direct-DBD method is its ability to design structures in a manner consistent with the level of damage expected, by directly relating the response and the expected performance of the structure. The research begins with a description of the procedural aspects of the Direct-DBD method and the parameters required for its application. The research presented focuses on the formulation of a displacement-based seismic design procedure, applicable to one-storey wooden structures made with a portal system. This typology is very common in Europe and particularly in Italy. A series of analytical expressions have been developed to calculate design parameters. The required analytical Direct-DBD parameters are implemented based on the mechanical behaviour of the connections, made with metal dowel-type fasteners. The calibration and subsequent validation of design parameters use a Monte Carlo numerical simulation and outcomes obtained by tests in full-scale. After the description of the Displacement-Based method for one-storey wooden structures, a series of guidelines to extend the Direct-DBD methodology to other types and categories of timber systems are proposed. The thesis presents the case of a multi-storey wood frame construction, which is a simple extension of the glulam portal frame system. Part of this work has been done within the RELUIS Project, (REte dei Laboratori Universitari di Ingegneria Sismica), Research Line IV, which in the years between 2005 and 2008 involved several Italian universities and Italian institutes of research in the development of new seismic design methods. The Project produced the first draft of model code for the seismic design of structures based on displacement (Direct-DBD). This thesis is the background to the section of the model code developed for timber structures.

ABSTRACT THE PERFORMANCE OF MEDIUM AND LONG SPAN TIMBER ROOF STRUCTURES: A COMPARATIVE STUDY BETWEEN STRUCTURAL TIMBER AND STEEL ERTASTAN, Evren M.S, in Building Science, Department of Architecture Supervisor: Assoc. Prof. Dr. Ercü
ment ERMAN December 2005, 174 pages This thesis analyzes the performance of structural timber and steel in medium and long span roof structures. A technical background about roof structures including structural elements and roof structure types, span definitions, and classification of roof structures are discussed. Roof structures are detailed with traditional and the contemporary forms. The thesis comprises the comparison between structural timber and steel by using structural, constructional and material properties. Structural forms and the performance of timber and steel are discussed. The research also includes the roof structures built with structural timber in Turkey, application, marketing and examples in Turkey are indicated. In the conclusion part the performance criteria of timber and steel are summarized, the researcher has prepared a table to compare the performance of timber and steel. Keywords: Timber, Steel, Roof, Structure, Span

How can we as design professionals contribute to increase the use of less carbon-intensive materials to build our growing cities? Cities are experiencing a resurgence in population growth and therefore the building industry ought to attend this demand with sustainable solutions. One way of responding to the growing urban population and increase demand for housing as well as to make efficient use of our limited resources is to increase the density in our cities. Since steel and concrete have high material strengths, we currently use either steel, concrete or composites of them to build skyscrapers. Unfortunately, both of these materials have a large carbon footprint. The design community has the challenge to achieve net-zero emissions buildings by the year 2030, and the efforts now should be focused on using less carbon intensive materials, such as timber. While cultures around the world have built with wood for centuries, recent technological innovations, such as Cross Laminated Timber (CLT), is allowing for new applications of wood as the main structural material and the potential to use it for large-scale projects. However, as expected with a new building material some constrains have still to be overcome. For my thesis, I desired to explore this issue through the design of a tall building using mass timber as its main structural material. Engineered timber is here, the future is bright!
Master of Architecture

The test scenarios ranged from fires in the structures with no exterior ventilation to room fires with flow paths that connected the fires with remote intake and exhaust vents. In the ranch, two replicate fires were conducted for each room of origin and each ventilation condition. Rooms of fire origin included the living room, bedroom, and kitchen. In the colonial, the focus was on varying the flow paths to examine the change in fire behavior and the resulting damage. No replicates were conducted in the colonial. After each fire scene was documented, the interior finish and furnishings were replaced in affected areas of the structure. Instrumentation was installed to measure gas temperature, gas pressure, and gas movement within the structures. In addition, oxygen sensors were installed to determine when a sufficient level of oxygen was available for flaming combustion. Standard video and firefighting IR cameras were also installed inside of the structures to capture information about the fire dynamics of the experiments. Video cameras were also positioned outside of the structures to monitor the flow of smoke, flames, and air at the exterior vents. Each of the fires were started from a small flaming source. The fires were allowed to develop until they self-extinguished due to a lack of oxygen or until the fire had transitioned through flashover. The times that fires burned post-flashover varied based on the damage occurring within the structure. The goal was have patterns remaining on the ceiling, walls, and floors post-test. In total, thirteen experiments were conducted in the ranch structure and eight experiments were conducted in the colonial structure. All experiments were conducted at UL's Large Fire Laboratory in Northbrook, IL. Increasing the ventilation available to the fire, in both the ranch and the colonial, resulted in additional burn time, additional fire growth, and a larger area of fire damage within the structures. These changes are consistent with fire dynamics based assessments and were repeatable. Fire patterns within the room of origin led to the area of origin when the ventilation of the structure was considered. Fire patterns generated pre-flashover, persisted post-flashover if the ventilation points were remote from the area of origin.

The article considers the model of the space-frequency-time continuum, according to which the physical essence of Time is manifested as a fraction of electromagnetic energy spent on updating a material object in a cyclic process of copying-incarnation. For all structural levels of physical reality, the value of this fraction is a fundamental constant, which can be represented as the tangent of the loss angle, or expressed in radians, as the angle of inclination of the evolutionary spiral, which characterizes the rate of change of states or the duration of events and processes. The value of this constant can be calculated, and its value turns out to be identically equals to the square of the fine structure Constant (α2). The description of the method for identifying a new constant allows us to present the formula of Scientific Discovery as the Physical Essence of Time.

This article explores the rationale behind a performance given by the authors at the Unfolding the Process symposium held in Oslo in November 2015. For this occasion, the authors devised a new version of Bach’s Goldberg Variations that builds upon Emmerson’s arrangement of the work for two pianos in 2012. A shortened version of the work (c.30 minutes) was designed that aimed nonetheless to maintain the original work’s sense of structural balance and coherence. This version involved the transposition of a number of variations into different keys to explore the possibility of adding a satisfying tonal structure to our experience of the work, in a context where both performers see potential communicative value in 'playing with' dimensions of original masterworks with a view to giving fresh perspective to the listener experience. The article is written from the alternating perspectives of the authors; one of which is primarily concerned with the rationale and process of devising the arrangement while the other reflects upon the performative aspects and implications arising from it.