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With the greatly increased rate of social and economic change in North America since World War II, the flexible/adaptable house has become an alternative to the conventional single-family, detached housing that both exceeds the needs and means of many non-traditional households. Theories and experience worldwide have shown that housing flexibility that is based on user participation allows decision-makers to adapt housing projects to meet the changing general needs. However, technological bottlenecks in the invention of new materials and techniques can restrict flexibility. This study examines construction products that contribute to increased flexibility in wood-frame low-rise housing. / Prefabrication has been the construction industry's approach to achieving housing flexibility. The strategy has been to incorporate flexibility into each subsystem or component through the use of new materials and techniques, in order to create overall building flexibility. The research presented in this thesis shows that different products offer different levels of flexibility, and that combining them does not necessarily produce greater overall flexibility. By examining the positive and negative aspects of these products, the author is able to suggest new directions for the development of future innovations in housing flexibility.

The consulting firm Atkins has developed a tool to help constructers plan urban areas but the tool is lacking data about embodied carbon in Sweden. The embodied carbon is the total carbon dioxide equivalents that are emitted from the material used in constructing a residential building as well as the energy used at the construction site and during demolition. In this thesis, the embodied carbon for a concrete framed building and a wooden framed building is calculated and presented. The mapping of embodied carbon for the two different framed buildings is done with a life cycle assessment perspective. In order to structure the studied system, the life cycle of the buildings is divided into three stages. The first stage includes data and calculations about the extraction and manufacturing of the most common building materials as well as the transportation to construction site. Stage 2 presents information about theon-site construction which includes, among other things, use of machines for constructing a residential building. In the third stage, data regarding demolition and end of life management are presented and calculated. All these three stages are added and a value for total embodied carbon for concrete framed residential buildings and wooden framed ones is presented in the result. The final result shows that the studied concrete framed residential building contains more embodied carbon than the wooden framed one. Further, stage 1 represents the largest part of embodied carbon, 87% for the concrete frame and 84% for the wooden frame, and stage 2 represents a very small part for both types of buildings, 1% for the concrete frame and 2% for the wooden fame.

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 thesis presents the results of experimental and analytical investigations into the performance of light-frame structures under lateral loading. The specific objectives of this research are to:1)develop simple, experimentally validated numerical models of light-Frame structures, which can be used to predict their performance under lateral loads, particularly seismic loads; and 2) collect experimental data suitable for validation of detailed finite-element models of light-frame structures.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 54-55). Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 2004. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.

Thesis (M.S.)--Brigham Young University. Dept. of Civil and Environmental Engineering, 2005. / Includes bibliographical references (leaves 185-207).

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references. Also available on the World Wide Web.

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Difficulties in characterizing the dynamic behavior of wood structures have hindered investigations into their performance under dynamic loading. Because of this, wood structures are treated unfavorably in seismic design codes, even though past damage assessment surveys after seismic events indicated generally satisfactory performance. To allow investigations into their performance and safety under dynamic loading, the energy dissipation mechanisms of wood joints and structural systems must be known and the hysteretic behavior modeled properly. This dissertation presents a general hysteresis model for wood joints and structural systems, based on a modification of the Bouc-Wen-Baber-Noori (BWBN) model. The hysteretic constitutive law, based on the endochronic theory of plastidty and characterized by a single mathematical form, produces a versatile, smoothly varying hysteresis that models previously observed behavior of wood joints and structural systems, namely, (1) nonlinear, inelastic behavior, (2) stiffness degradation, (3) strength degradation, (4) pinching, and (5) memory. The constitutive law takes into account the experimentally observed dependence of wood joints' response to their past history (i.e., the input and response at earlier times, or memory). Practical guidelines to estimate the hysteresis parameters of any wood joint or structural system are given. Hysteresis shapes produced by the proposed model are shown to compare favorably with experimental hysteresis of wood joints with; (1) yielding plates, (2) yielding nails, and (3) yielding bolts. To verify its behavior under arbitrary dynamic loadings, the proposed model is implemented in a nonlinear dynamic analysis program for single-degree-of-freedom (SDF) systems. Three SDF wood systems are subjected to the Lama Prieta accelerogram to obtain their response time histories. Advantages of using the proposed model over currently available models in nonlinear dynamic analysis of more complex systems are identified. A multi-degree-of-freedom shear building model incorporating the proposed hysteresis model is formulated but not implemented on a computer. For more realistic loadings, the random characteristics of earthquakes are modeled as a stochastic or random process. Nonlinear response statistics of SDF wood systems are obtained by Monte Carlo simulation and statistical linearization The statistical linearization solutions are shown to give reasonably good estimates of mean-square response, for a range of practical system and model parameter values. An example verification procedure that can be used in applying the method to practical engineering problems is presented. The response analysis technique is general and can be applied not only in random vibration analysis of wood structural systems but also in the analysis of a wide variety of hysteretic systems with general pinching behavior, including reinforced concrete structures, braced steel frames and laterally loaded piles. Potential practical applications of the analysis method and of the response statistics obtained from the analysis are presented. The present work is the first known attempt to use random vibration techniques in studying the response of wood structures under natural hazard loadings. / Ph. D.