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Strength model and finite element analysis of wood beam-columns in truss applications Lau, Wilson Wai Shing
Abstract
A. comprehensive stochastic finite element model for analyzing and predicting the load carrying capacity of beams and beam-columns is developed and presented. By incorporating the stochastic lumber properties, the model characterizes the within-member and betweenmember variability of the lumber properties to predict the response variability in the load carrying capacity. Applications of the model require the determination of model parameters by calibrating the model with experimental data. An extensive experimental program on a large number of members in both compact and structural sizes was conducted. In order to confirm the validity of the model, the model has been verified by comparing results obtained from additional full-size testing. The finite element model utilizes one-dimensional beam elements incorporating large displacement but small strains. Due to the large inherent displacements and yielding of the members before reaching the ultimate load, non-linearities in both geometry and material are assumed. In addition, a new stress-strain equation is proposed. The Newton-Raphson Method was also used to iterate to the true solution at each load step. Specific material properties of the member are modeled as one-dimensional stochastic field variables in the finite element program. As these properties may not be ergodic stationary processes, trend removal and normalization procedures were used to transform these material property processes into ergodic stationary processes. Fast Fourier transform was utilized to obtain the spectrum, transfer functions and coherence functions of these properties. Both auto- and cross-spectra were studied so that correlations between these processes were maintained during the simulations. Realizations of the material properties were simulated by a single input - multiple output random field model. Trends were then added to these ergodic stationary processes to generate the lumber properties. The interaction relation between applied axial load and moment was also studied. Using the finite element program and the random field model, the interaction behaviour of axial load and moment was simulated and percentile statistics were determined accordingly. Several other applications of the model and the finite element program are discussed, including the evaluation of the existing codes, axial load-slenderness curves, size, and load configuration effects.
Item Metadata
Title |
Strength model and finite element analysis of wood beam-columns in truss applications
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2000
|
Description |
A. comprehensive stochastic finite element model for analyzing and predicting the load
carrying capacity of beams and beam-columns is developed and presented. By incorporating
the stochastic lumber properties, the model characterizes the within-member and betweenmember
variability of the lumber properties to predict the response variability in the load
carrying capacity. Applications of the model require the determination of model parameters
by calibrating the model with experimental data. An extensive experimental program on a
large number of members in both compact and structural sizes was conducted. In order to
confirm the validity of the model, the model has been verified by comparing results obtained
from additional full-size testing.
The finite element model utilizes one-dimensional beam elements incorporating large
displacement but small strains. Due to the large inherent displacements and yielding of the
members before reaching the ultimate load, non-linearities in both geometry and material are
assumed. In addition, a new stress-strain equation is proposed. The Newton-Raphson Method
was also used to iterate to the true solution at each load step.
Specific material properties of the member are modeled as one-dimensional stochastic
field variables in the finite element program. As these properties may not be ergodic
stationary processes, trend removal and normalization procedures were used to transform
these material property processes into ergodic stationary processes. Fast Fourier transform
was utilized to obtain the spectrum, transfer functions and coherence functions of these
properties. Both auto- and cross-spectra were studied so that correlations between these
processes were maintained during the simulations.
Realizations of the material properties were simulated by a single input - multiple
output random field model. Trends were then added to these ergodic stationary processes to
generate the lumber properties. The interaction relation between applied axial load and
moment was also studied. Using the finite element program and the random field model, the
interaction behaviour of axial load and moment was simulated and percentile statistics were
determined accordingly.
Several other applications of the model and the finite element program are discussed,
including the evaluation of the existing codes, axial load-slenderness curves, size, and load
configuration effects.
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Extent |
12553887 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-07-23
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0089810
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2000-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.