Software Tour
Analysis Capabilities
The unrivalled state-of-the-art element libraries,
isotropic and orthotropic material models in LUSAS Civil & Structural, allow
all types of civil and structural engineering problem to be solved.
Analysis
capability is dependent upon the product in use. The analysis
capabilities of particular LUSAS Civil & Structural software
products can be extended by using software options. For details see the Product Specification.
Linear static
Stresses, strains,
displacements, moments, shears and axial forces that result from
static loading are easily calculated, displayed and output from any
model. Loads are assumed to be
applied instantaneously in order to develop the state of internal stress and transient
effects are ignored.
Buckling
LUSAS carries out
elastic critical buckling, which is required for the calculation of
member resistances. Often it is also required by some codes to
determine if a second-order analysis needs to be carried out. If so, a
full nonlinear buckling analysis can be undertaken.
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Fatigue
Fatigue calculations
can be carried out using the total life approach. Fatigue life may be
expressed in terms of the damage that is done to the structure by a
prescribed loading sequence or as the number of repeats of a sequence
that will cause failure
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Dynamics
The natural frequency
of structures, the effect of dynamic loading, such as crowds in sports
stadiums and auditoriums, blast loading, and the response due to
earthquake or impact loading can all be readily calculated.
Interactive Modal
Dynamics (Modal superposition)
Interactive Modal
Dynamics (IMD) allows the natural vibration behaviour of a structure
to be combined with a loading regime in order to calculate the dynamic
response of a structure to a range of applied excitations. IMD
produces results an order of magnitude faster than traditional
time-step solutions. Multiple and more advanced loading events
(including moving loads and nonlinear behaviour) can be modelled with
the IMDPlus and additional software options.
Nonlinear
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LUSAS Civil &
Structural handles geometric nonlinearity, material nonlinearity and
contact nonlinearity to accurately model the structural behaviour.
Local and global nonlinear analysis with LUSAS helps ensure that
structures are designed economically and safely for any imposed
loading. Automatic nonlinear solution procedures simplify the analysis
process for applications such as:
- Time-dependent
dynamic analysis
- Lift-off of bearings
and halving joints
- Bearing analysis
- Elasto-plastic large
deflection plate buckling
- Concrete cracking
- Concrete creep with
recovery
- Thermal loading
- Impact / collapse
assessments
- ‘Push-over’
analysis
- Excavation and
construction
- Soil-structure
interaction
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Staged construction
Staged construction
analysis with LUSAS provides you with the means to model the
step-by-step construction or rebuilding of your structure over time
and evaluate the effects of structural changes, load applications, and
if required, time-dependent material changes. The complete staged
construction analysis process for a model is controlled in a loadcase
panel of the LUSAS Treeview. When modelling, groups of elements and
associated attributes can be activated and deactivated, and supports
can be introduced or removed to accurately represent each stage of
construction.
With LUSAS Civil &
Structural, unlike some software, only one model file need be created
and this can contain all of the information required to carry out an
analysis of every stage of construction. The effects of geometric and
material nonlinearity, and time-dependent material effects such as
creep and shrinkage can all be included within the one analysis run.
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Full staged
construction modelling with beams, shells and solid elements.
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Full activation and
deactivation of elements.
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Add or remove
supports as required during the construction sequence.
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Sliding bearings may
be modelled using nonlinear contact (slidelines).
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Support and loading
facilities including temporary/traveller loads.
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Apply loads anywhere
onto any model.
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Change
loading/stress/strain over time and lock-in stresses between
stages.
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Prescribed
displacements or jacking loads may be used as spans are completed.
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Time-dependent
material properties include stress related concrete creep and
shrinkage for fib (formerly CEB-FIP) and Chinese model
codes.
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Custom
time-dependent curves for particular material properties and
codes.
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Use single or
multi-tendon wizards to define and assign tendon properties and
time-stages to features of a model.
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Steel relaxation,
time effect on elastic modulus, tendon post-tensioning losses.
from creep, shrinkage, and superimposed loads.
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Cumulative effects
can be reported separately for each loadcase, such as
post-tensioning effects, or for the effects of just creep and
shrinkage.
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Incremental effects
can also be specified allowing you to view and assess the net
changes to the structure since the previous stage.
Soil-structure
interaction
Geotechnical
capabilities make use of a range of soil models. Residual soil stress
varying with depth can be accommodated providing facilities for
soil-structure interaction for pile group/pilecap design. Rock joints,
pore water pressure dissipation, consolidation modelling, geotechnical
problems involving long term excavation, construction in clays, and
temporary works can all be solved.
Thermal / Field
analysis
The Thermal
/ Field software option contains extensive facilities for both
simple and advanced steady state, and transient thermal / field
analyses. By combining the LUSAS Thermal / Field option with other
appropriate LUSAS options, heat transfer due to conduction, convection
and radiation can be analysed. In addition, the effects due to phase
change of material may also be included. For large concrete
structures such as cooling towers, dams, caissons and other large
foundation bases, steady state and transient thermal analyses can be
done with or without thermal-structural coupling. Modelling of heat of
concrete hydration can be done for a variety of cement types using the
using the Heat of Hydration option.
 Heat
of hydration
Modelling
of heat of concrete hydration can be carried out for a variety of
cement types using the using the Heat
of Hydration software option. Effects due to the addition of fly
ash and ground granulated blast furnace slag can also be included.
When used in conjunction with Nonlinear, Dynamic, and Thermal software
options the heat of concrete hydration can be computed during a
thermo-mechanical coupled analysis and the temperatures and degree of
hydration can be read in to the mechanical analysis.
Faster
solution times
The Fast
Solver option comprises three solvers for use with particular
LUSAS Bridge products.
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The
Fast Multifrontal Direct Solver can provide solutions several
times faster than the standard Frontal Direct Solver for certain
analysis problems.
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The
Fast Multifrontal Block Lanczos Eigensolver can, similarly, return
results.
several times faster than the standard Frontal Eigensolvers for
certain problems.
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The
complex eigensolver provides efficient solutions for large-scale
damped natural frequency problems.
 Customisation
and automation
The LUSAS
Programmable Interface (LPI) allows customisation
of modelling
and results processing tasks to your specific requirements. By using
VBScript to access LUSAS facilities and functionality direct links to
Word and Excel can be made for data transfer, the parameterisation of
structures can be achieved, repetitive tasks can be automated, and
results processing procedures can be customised.
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