Technical Papers
Describes the development of the Indian River Inlet Bridge in Delaware, which
was designed using LARSA 2000/4D.
Describes the development of a material nonlinear three-dimensional beam
column element in IDARC3D, which makes use of LARSA 2000's plugin capabilities.
Two hysteretic models (a polygonal model and a smooth model) for inelastic
behavior of macro-models of structural components are developed. These models
can simulate the deteriorating behavior of strength, stiffness, and bond slip.
The theoretical background, the development and the implementation of these
models are presented. The report shows a holistic picture of the modeling of
one-dimensional inelastic material behavior and indicates how various hysteretic
models are obtained from the basic principles of mechanics and thermodynamics
through numerous assumptions, which lead to certain approximations. Finally, the
incorporation of the hysteretic models into two computer programs (IDARC2D and
NSPECTRA) is described. The appendix focuses on the implementation details of
the polygonal hysteretic model.
A comprehensive structural analysis of the United States Capitol's dome reveals
that the dome is sound and capable of resisting all reasonably anticipated
loadings.
LZA chose a prerelease version of
LARSA, produced by LARSA, Inc., of New York City, which uniquely provided most
of the desired criteria. Initially the run time for the model used took three
and a half hours . . . LARSA provided support and a first-generation matrix
numerical solver technique that cancels out zeros at unrestrained degrees of
freedom and reduces the bandwidth, resulting in a run time of just seven
minutes.
The world's largest cable dome, to be completed for the 1992 football season in
Atlanta, will be the centerpiece of the 1996 Olympic Games. Spanning 766 ft x
610 ft (233.5 m x 186 m), it will be the first Hypar-Tensegrity Dome. This new
cable supported teflon-coated fabric roof is based on the tensegrity principles
first enunciated by Buckminster Fuller and Kenneth Snelson. Because of the large
deformation characteristics of this type of structures, special geometric
nonlinear analysis is required. This paper describes the modeling and the
behavior of the roof for the Georgia Dome under different loadings.
A software package like LARSA
provides not only the answer to the every day analysis and design problem but
also the nonlinear solutions that large deformation structures require. This
leads to the ability to economically construct complex structures which would
not otherwise be feasible, opening the door to an exciting range of
possibilities limited only by the creativity of the
engineer.
