An examination of static and dynamic dent resistance of structural panel assemblies representing automotive hoods is described in this thesis. Fabricated panel assemblies incorporating typical components of real automotive parts were tested. The panel assemblies included an AA5754 inner panel using an array of teacup supports and an AA6111 closure panel joined with automotive mastic. The assemblies allowed for parametric assessment of numerous factors affecting dent resistance including: panel thickness, panel curvature, panel support configuration and dent site location. An extensive experimental program evaluated various panel combinations under both static and dynamic denting conditions. The measured results illustrate various trends of the different factors affecting dent resistance. The experimental database allows a qualitative assessment of dent resistance for full-scale automotive parts. The importance of support conditions is highlighted. The influence of mastic thickness is found to be a critical consideration. Numerical simulations of the dent test were undertaken using finite element techniques. The numerical predictions offer varying degrees of accuracy. The quantitative results are limited, due to numerical concerns, but the qualitative trends are generally well captured. As well, the relative importance of the various parametric factors is well represented in the numerical results. The interaction of the components at the teacup supports proved to critical to the predictive ability of the models. The method developed to model the interaction was somewhat limited by the available material models within the numerical code used, but offers promise for improved results in future simulations. The modelling method is readily transferred to full-scale automotive panels for assessment of dent resistance early in the design cycle.

An examination of static and dynamic dent resistance of structural panel assemblies representing automotive hoods is described in this thesis. Fabricated panel assemblies incorporating typical components of real automotive parts were tested. The panel assemblies included an AA5754 inner panel using an array of teacup supports and an AA6111 closure panel joined with automotive mastic. The assemblies allowed for parametric assessment of numerous factors affecting dent resistance including: panel thickness, panel curvature, panel support configuration and dent site location. An extensive experimental program evaluated various panel combinations under both static and dynamic denting conditions. The measured results illustrate various trends of the different factors affecting dent resistance. The experimental database allows a qualitative assessment of dent resistance for full-scale automotive parts. The importance of support conditions is highlighted. The influence of mastic thickness is found to be a critical consideration. Numerical simulations of the dent test were undertaken using finite element techniques. The numerical predictions offer varying degrees of accuracy. The quantitative results are limited, due to numerical concerns, but the qualitative trends are generally well captured. As well, the relative importance of the various parametric factors is well represented in the numerical results. The interaction of the components at the teacup supports proved to critical to the predictive ability of the models. The method developed to model the interaction was somewhat limited by the available material models within the numerical code used, but offers promise for improved results in future simulations. The modelling method is readily transferred to full-scale automotive panels for assessment of dent resistance early in the design cycle.

Guadua angustifolia Kunth (Guadua) is a bamboo species native to South and Central America that has been widely used for structural applications in small and large-scale buildings, bridges and temporary structures. Currently, its structural use is regulated within seismic resistant building codes in countries such as Peru and Colombia. Nevertheless, Guadua remains a material for vernacular construction associated with high levels of manual labour and structural unpredictability. Guadua buildings are limited to two storeys due to the overall flexibility of the slender and hollow culms and its connection systems. Its axial specific stiffness is comparable to that of steel and hardwoods, but unlike wood, Guadua’s hollow structure and lack of ray cells render it prone to buckling along the grain and to transverse crushing. As a result, Guadua’s mainstream use in construction and transformation into standard sizes or engineered Guadua products is scarce. Therefore, this work focussed on the development of standardised flat industrial structural products from Guadua devising replicable manufacturing technologies and engineering methods to measure and predict their mechanical behaviour. Cross-laminated Guadua panels were developed using thermohydro-mechanically modified and laminated flat Guadua strips glued with a high performance resin. Guadua was subjected to thermo-hydro-mechanical (THM) treatments that modified its microstructure and mechanical properties. THM treatment was applied to Guadua with the aim of tackling the difficulties in the fabrication of standardised construction materials and to gain a uniform fibre content profile that facilitated prediction of mechanical properties for structural design. Densified homogenous flat Guadua strips (FGS) were obtained. Elastic properties of FGS were determined in tension, compression and shear using small-clear specimens. These properties were used to predict the structural behaviour of G-XLam panels comprised of three and five layers (G-XLam3 and G-XLam5) by numerical methods. The panels were assumed as multi-layered systems composed of contiguous lamellas with orthotropic axes orientated at 0º and 90º. A finite element (FE) model was developed, and successfully simulated the response of G-XLam3 & 5 panels virtually loaded with the same boundary conditions as the following experimental tests on full-scale panels. G-XLam3 and G-XLam5 were manufactured and their mechanical properties evaluated by testing large specimens in compression, shear and bending. Results from numerical, FE predictions and mechanical testing demonstrated comparable results. Finally, design and manufacturing aspects of the G-XLam panels were discussed and examples of their architectural and structural use in construction applications such as mid-rise buildings, grid shells and vaults are presented. Overall, this research studies THM treatments applied to Guadua in order to produce standardised engineered Guadua products (EGP), and provides guidelines for manufacturing, testing, and for the structural analysis and design with G-XLam panels. These factors are of key importance for the use of Guadua as a mainstream material in construction.

A tese buscou identificar, a partir da análise da cadeia produtiva de produtos de base florestal, as oportunidades para aproveitamento da madeira roliça dos gêneros Eucalyptus e Pinus, com pequeno diâmetro, para produção de painéis estruturais de vedação destinados a habitação social. A madeira como material construtivo renovável, e segundo as dimensões da sustentabilidade, econômica e ambiental, apresenta as seguintes potencialidades: plantio e manejo florestal sustentável; adequação a diversos sistemas estruturais e construtivos; baixos consumos de energia e baixa geração de resíduos no processo de produção; desmontagem e aproveitamento dos resíduos no processo de transformação. O método adotado para o desenvolvimento do produto painel foi baseado, na análise e aperfeiçoamentos sucessivos a partir da avaliação dos dados coletados na fase experimental (processo de produção). As variáveis consideradas foram: facilidade de produção (homem/minuto, hora/equipamento e ferramentas), volume de resíduos gerados no processamento, custos e facilidade de montagem do painel. Os critérios adotados na avaliação de desempenho técnico foram: estrutural, estanqueidade visual e durabilidade. Na avaliação da sustentabilidade ambiental foram: uso de materiais de fontes renováveis; baixo consumo energético; redução de resíduos gerados. A sustentabilidade econômica foi avaliada considerando os critérios de: facilidade de produção; facilidade de montagem; produção em escala; baixos custos dos materiais empregados. Foram desenvolvidos e avaliados 10 projetos segundo os critérios considerados, concluindo-se com a proposição do produto painel estrutural composto por 1/2 peças roliças de eucalipto com pequeno diâmetro, curtas, justapostas e pregadas à chapa OSB (oriented strand board). O painel tem dimensões fracionadas na altura e na largura da chapa (1,22 x 2,44 m), nas seguintes medidas: 0,61 x 2,44; 0,61 x 1,22; 1,22 x 1,22 m; 1,22 x 2,44 m. Esta composição do painel viabiliza o melhor aproveitamento das peças chamadas de “metrinho", as quais 100% são destinadas atualmente para queima na geração de energia (desde fornos de padarias até fornos industriais). A proposta mostrou ser viável e pode-se constatar a sua facilidade de execução, mesmo em situações precárias de maquinários. A adoção dessas simplificações construtivas para a produção de componentes construtivos para habitações pode representar uma oportunidade de redução do tempo de execução e dos custos de produtos que atendam ao setor da habitação de baixa renda. A proposta apresenta ainda uma contribuição para a melhoria nas condições de moradia e redução dos impactos negativos ao meio ambiente, gerados pela construção civil, na utilização de materiais não renováveis. / The purpose of this work is to identify, from the analysis of the production chain of forest based products, the chances of making use of small diameter round-wood of the Eucalyptus and Pinus types, for the production of sealing structural panels destined for social housing. Wood as a renewable building material – and, in accordance with the environmental and economic dimensions of sustainability – presents the following potentialities: sustainable forest planting and handling; adequacy to several building and structural systems; low energy consumption and low residual outcome during the production process; dismantling and reuse of the remnants in the transformation process. The method adopted for the development of the panel product was grounded on the analysis and consecutive improvement, which was based on the evaluation of the data collected in the experimental phase (production process). The following variables were considered: production easiness (man/minute, time/equipment and tooling), amount of remnant generated by the processing, cost and panel mounting easiness. The criteria adopted in the evaluation of technical execution were the following: structural, visual tightness and durability. The following criteria were used in the environmental sustainability evaluation: use of materials from renewable sources; low energy consumption; reduction of residual outcome. The economic sustainability was evaluated taken the following criteria into consideration: production easiness; mounting easiness; mass production, low cost of the materials used. Ten projects have been developed and evaluated according to the considered criteria, and the structural panel product comprising juxtaposed, short, small diameter, eucalyptus, half round-wood pieces, nailed to OSB (oriented strand board) plate, was proposed. The panel has dimensions fractionized in the height and the width of the plate (1.22 x 2,44 m), in the following measures: 0.61 x 2.44; 0.61 x 1.22; 1.22 x 1.22 m; 1.22x 2.44 m. This panel composition enables for best utilization of the so called metrinho (small pieces) pieces, which, nowadays, are 100% used in burning for the generation of energy (from bakery to industrial ovens). The proposal has shown to be doable and of easy execution, even in precarious machinery situations. The adoption of these building simplifications for the production of building components for housing may represent an opportunity to reduce the execution time, as well as the products cost, in order to serve the low income housing sector. The proposal also presents a contribution to the improvement of housing conditions and to the reduction of negative environmental impacts, caused by the civil construction through the use of non-renewable materials.

A tese buscou identificar, a partir da análise da cadeia produtiva de produtos de base florestal, as oportunidades para aproveitamento da madeira roliça dos gêneros Eucalyptus e Pinus, com pequeno diâmetro, para produção de painéis estruturais de vedação destinados a habitação social. A madeira como material construtivo renovável, e segundo as dimensões da sustentabilidade, econômica e ambiental, apresenta as seguintes potencialidades: plantio e manejo florestal sustentável; adequação a diversos sistemas estruturais e construtivos; baixos consumos de energia e baixa geração de resíduos no processo de produção; desmontagem e aproveitamento dos resíduos no processo de transformação. O método adotado para o desenvolvimento do produto painel foi baseado, na análise e aperfeiçoamentos sucessivos a partir da avaliação dos dados coletados na fase experimental (processo de produção). As variáveis consideradas foram: facilidade de produção (homem/minuto, hora/equipamento e ferramentas), volume de resíduos gerados no processamento, custos e facilidade de montagem do painel. Os critérios adotados na avaliação de desempenho técnico foram: estrutural, estanqueidade visual e durabilidade. Na avaliação da sustentabilidade ambiental foram: uso de materiais de fontes renováveis; baixo consumo energético; redução de resíduos gerados. A sustentabilidade econômica foi avaliada considerando os critérios de: facilidade de produção; facilidade de montagem; produção em escala; baixos custos dos materiais empregados. Foram desenvolvidos e avaliados 10 projetos segundo os critérios considerados, concluindo-se com a proposição do produto painel estrutural composto por 1/2 peças roliças de eucalipto com pequeno diâmetro, curtas, justapostas e pregadas à chapa OSB (oriented strand board). O painel tem dimensões fracionadas na altura e na largura da chapa (1,22 x 2,44 m), nas seguintes medidas: 0,61 x 2,44; 0,61 x 1,22; 1,22 x 1,22 m; 1,22 x 2,44 m. Esta composição do painel viabiliza o melhor aproveitamento das peças chamadas de “metrinho”, as quais 100% são destinadas atualmente para queima na geração de energia (desde fornos de padarias até fornos industriais). A proposta mostrou ser viável e pode-se constatar a sua facilidade de execução, mesmo em situações precárias de maquinários. A adoção dessas simplificações construtivas para a produção de componentes construtivos para habitações pode representar uma oportunidade de redução do tempo de execução e dos custos de produtos que atendam ao setor da habitação de baixa renda. A proposta apresenta ainda uma contribuição para a melhoria nas condições de moradia e redução dos impactos negativos ao meio ambiente, gerados pela construção civil, na utilização de materiais não renováveis. / The purpose of this work is to identify, from the analysis of the production chain of forest based products, the chances of making use of small diameter round-wood of the Eucalyptus and Pinus types, for the production of sealing structural panels destined for social housing. Wood as a renewable building material – and, in accordance with the environmental and economic dimensions of sustainability – presents the following potentialities: sustainable forest planting and handling; adequacy to several building and structural systems; low energy consumption and low residual outcome during the production process; dismantling and reuse of the remnants in the transformation process. The method adopted for the development of the panel product was grounded on the analysis and consecutive improvement, which was based on the evaluation of the data collected in the experimental phase (production process). The following variables were considered: production easiness (man/minute, time/equipment and tooling), amount of remnant generated by the processing, cost and panel mounting easiness. The criteria adopted in the evaluation of technical execution were the following: structural, visual tightness and durability. The following criteria were used in the environmental sustainability evaluation: use of materials from renewable sources; low energy consumption; reduction of residual outcome. The economic sustainability was evaluated taken the following criteria into consideration: production easiness; mounting easiness; mass production, low cost of the materials used. Ten projects have been developed and evaluated according to the considered criteria, and the structural panel product comprising juxtaposed, short, small diameter, eucalyptus, half round-wood pieces, nailed to OSB (oriented strand board) plate, was proposed. The panel has dimensions fractionized in the height and the width of the plate (1.22 x 2,44 m), in the following measures: 0.61 x 2.44; 0.61 x 1.22; 1.22 x 1.22 m; 1.22x 2.44 m. This panel composition enables for best utilization of the so called metrinho (small pieces) pieces, which, nowadays, are 100% used in burning for the generation of energy (from bakery to industrial ovens). The proposal has shown to be doable and of easy execution, even in precarious machinery situations. The adoption of these building simplifications for the production of building components for housing may represent an opportunity to reduce the execution time, as well as the products cost, in order to serve the low income housing sector. The proposal also presents a contribution to the improvement of housing conditions and to the reduction of negative environmental impacts, caused by the civil construction through the use of non-renewable materials.