Banca de DEFESA: JOSE HUMBERTO MATIAS DE PAULA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JOSE HUMBERTO MATIAS DE PAULA
DATE: 22/09/2023
TIME: 14:00
LOCAL: Videoconferência - http://ppgfau.unb.br/component/agenda/agendas
TITLE:

MODELS OF RESISTANCE AND DESIGN MODELS FOR TROPICAL WOOD STRUCTURAL ELEMENTS USING THE BASIC DENSITY

KEY WORDS:

1. Timber Structures 2. Wood Strength Models 3. Wood Basic Density 4. Timber Design Models

PAGES: 347
BIG AREA: Ciências Sociais Aplicadas
AREA: Arquitetura e Urbanismo
SUMMARY:

This Tesis presents the formulation of a mathematical model of material strength and structural design models
of tropical wood elements using basic density. The material strength models, in the proposed theoretical conception, have the basic density of wood as an independent variable in simple linear regression models and both basic density and wood grain in multiple linear regression models. The design models use mathematical functions that simulate the mechanical strength and stiffness of the material to develop a complete design solution for axial tension, axial compression, simple bending, combined axial load and bending, and wood connections. The formulation of the design models is based on deterministic and probabilistic safety models, independently using the prescriptions of different editions of the Brazilian wood standard: NBR-7190/82, based on deterministic model, NBR-7190/97 and the recent edition of NBR-7190/22, both based on
probabilistic safety models. The design model was developed from the latest version of the European code
Eurocode 5/2004-Part 1-1: Design of Timber Structures. In future editions of the text, the model will be
adapted to the American wood structural design codes: NDS-National Design Standard and ASCE-American
Society of Civil Engineering, and the Canadian standard: CSA 086.1 Engineering Design in Wood (Limit
States Design). The mathematical models of material strength and stiffness were estimated by seeking the relationship between variables through a simple linear regression model when the independent variable was only one, the basic density. When studying the relationship between variables with more than one explanatory independent variable (two quantitative variables or one quantitative variable associated with dichotomous qualitative variables), mathematical models capable of describing and predicting the dependent variable (mechanical strength or stiffness) were established using multiple linear regression models. For the development of the strength models, the sample base used was the Database of the Laboratory of Forest Products (LPF) of the Ministry of Environment of Brazil, which is the result of a consistent experimental program conducted over the last thirty-seven years. This experimental campaign characterized 259 species of tropical wood from the Amazon, with reference to the Pan-American Standards COPANT-Pan American Commission of Technical Standards, based on ASTM-American Society for Testing and Materials standards.
A comprehensive and robust statistical inference analysis of the strength and design models is
presented in the book to validate the proposed formulation. An extensive set of statistical tests, verification of
assumptions, and analyses of Bland-Altman agreement between experimental and mathematical models are
presented and discussed. It is possible to conclude, based on the statistical inference analysis and crossvalidation of Bland-Altman agreement from external samples to the Database used, that the proposed
mathematical strength model using basic density is mathematically and statistically significant and consistent,
but it is also capable of simulating any tropical forests from any continent. Therefore, the mathematical strength and design models constitute a new design tool for tropical wood structures. The method based on the proposed mathematical models is much simpler and broader than the conventional method based on experimental data, in addition to being statistically significantly safe. Hence, it can be stated that the difference between the results of designing tropical wood structural elements using the conventional experimental model and the mathematical model using the basic density of the wood is statistically negligible, as demonstrated in the body of the book. The unprecedented research results have already been published and presented in scientific congresses, but from now on, articles will be written for relevant scientific journals and magazines

COMMITTEE MEMBERS:
Interno - 2352146 - JOAO DA COSTA PANTOJA
Presidente - 404714 - JOSE MANOEL MORALES SANCHEZ
Externo à Instituição - JULIO EUSTAQUIO DE MELO - OUTROS
Externo ao Programa - 3212150 - LENILDO SANTOS DA SILVA - nullExterno à Instituição - MARCO AURELIO SOUZA BESSA - CEUB