Primary Modules	Limitations
Hardware Supported	Element Types
Loadings	Material Types
The Solvers in Detail	Interfaces Available

DOCUMENTATION

PRIMARY MODULES

	Three dimensional input.
	Interactive element definitions.
	Interactive and automatic mesh generation.
	Numerous tools such as copy, extrude, sweep, project, move, intersect, scale, shrink, expand etc.
	Global or user-defined cartesian or polar co-ordinate systems.
	Automatic graphical assignment of node and element attributes by "pointing and clicking".
	ASCII output of all model data.
	Combine different models into a single structure.
	Display of models as wireframe, solid, hidden line removal, light shaded, property shaded.
	Dynamic rotation of model space for viewing.
	Display manipulation tools such as zoom, scale, pan, rotate, hide.

	Linear combination of primary load cases to define secondary load cases.
	Linear combination of primary load cases to define secondary load cases.
	Display of deformed model.
	Display of contours of displacement, stress, strain, moments, curvatures etc.
	Display of principal stress vectors.
	On-line axial force, shear force, bending moment and torque diagrams for beams, in 2D or 3D.
	XY-Plot of many result parameters.
	Stress variations over beam cross-sections.
	Multi window, multi view capability.
	ASCII output of all solution data.
	Full colour, full 3D animation of deflected displays with or without contours, also available in multi window mode.
	Interactive interrogation of results directly on the graphics image, simply by "pointing and clicking".
	Built-in print manager providing high quality graphical output to most popular dot matrix, laser and inkjet printers.

Linear Static.
Natural Frequency.
Transient Dynamics.
Harmonic Response.
Spectral Response.
Buckling.
Steady State Heat - Linear/Nonlinear.
Transient Heat - Linear/Nonlinear.
Nonlinear Statics (Geometric and Material).

LIMITATIONS

Maximum Number of Nodes	Not Limited
Maximum Number of Elements	Not Limited
Maximum Number of Material Types	Not Limited
Maximum Number of Degrees of Freedom	Not Limited

HARDWARE SUPPORTED

DOS Based PC's

• VGA or Super VGA graphics in 16 or 256 colours, in resolutions up to 1024 x 768.
  
• Full 32 bit utilisation including use of all available extended (XMS) memory.
  Minimum PC Configuration
  80386 DX with Co-Processor, VGA Graphics, Mouse, 4MB RAM and 100MB HD.
  Recommended PC Configuration
  Pentium Processor with 16MB RAM, SVGA Graphics, Mouse, 1GB HD.
  
  

Unix Based Workstations with X-Windows

• Silicon Graphics
  
• Hewlett Packard
  
• SUN
  
• IBM RS6000
  
• DEC
  

Windows95 and Windows NT

• Due for release, in 1997.
  

ELEMENT TYPES

	Truss and Spring elements
	General Beam element in 2D and 3D
	This element caters for arbitrary section shapes and includes offset nodes and shear centres which are not coincident with the section centroid.
	2D Plane Stress, Plane Strain and Axisymmetric elements - both linear and quadratic elements are available.
	2D and 3D Plate and Shell elements - both linear and quadratic elements are available for thin or thick shell analysis.
	3D brick elements including Tetrahedra, Wedges and Hexahedra.
	Point Masses.
	Gap elements.
	Friction elements.
	Cable elements.
	Multipoint nodal constraints.
	Library of standard beam sections and the ability to easily generate arbitrary sections of any shape.

Truss and Beam Elements. (1D, 2D, 3D)


Plane Stress/Plane Strain/Axisymmetric/Plate/Shell Elements. (2D, 3D)


Brick Elements. (3D)

LOADINGS

Linearly Varying Distributed loads.
Point Loads/Moments.
Uniformly Distributed Loads.
Pressures.
Stresses.
Shears.
Thermal Loading.
Global Linear and Angular Acceleration.
Global Angular Velocity.
Convection.
Radiation.
Flux.
Enforced Displacements.
Time Dependent Loads.

MATERIAL TYPES

Isotropic.
Orthotropic.
Temperature Dependent.
Non-linear Stress/Strain Relationships [Piecewise Linear or Ramberg-Osgood].
Mooney-Rivlin Rubber Model.
Mohr-Coulomb Soil Model.
Laminated Composites.

THE SOLVERS IN DETAIL

General

• Degrees of freedom may be fixed in global coordinates or in local coordinates via constraint equations to model inclined supports.
  
• Drilling freedoms are automatically suppressed for plate/shell elements.
  
• Automatic check of force equilibrium.
  
• Automatic detection of global rigid body motion.
  
• User definable default values for tolerances such as minimum element dimensions and zero pivot in solver.
  
• Automatic bandwidth minimization.
  
• Log files in ASCII format are automatically created, reporting progress, errors etc.
  

Linear Static Solver

• Linear Static Analysis is used for calculating the deflections, forces, stresses and strains in a structure as a result of a static loading. Combinations of the primary load cases are readily generated.
  
• Assembles the elements and calculates displacements due to any applied loadings.
  
• Different element types may be combined together.
  
• Fast, out of core, skyline solver.
  
• Calculates stress, strains, moments, curvatures.
  
• Allows the recovery of reactions.
  
• The results of a thermal (heat flow) analysis may be used for thermal stressing.
  
• Up to 20 load cases may be solved simultaneously.
  
• Up to 80 secondary load case combinations may be defined.
  

Natural Frequency Solver

• Natural frequency analysis is used to determine the undamped natural vibration frequencies and associated mode shapes of a structure.
  
• Uses the Subspace algorithm to calculate up to 100 eigenvalues and modes at a time.
  
• An optional shift may be included to determine higher or rigid body modes.
  
• The results of a linear static analysis may be used to calculate the stress stiffness matrix for inclusion in the vibration analysis.
  
• Mass distribution may be consistent or lumped.
  

Transient Dynamics

• Transient dynamic analysis is used to determine the response of a structure to loading which varies as a function of time. The loading may be any arbitrary time history loading. Structural and discrete damping may be included.
  
• Both the Newmark and Wilson methods are available.
  
• Either a Full System or a Mode Superposition method may be used.
  
• Rayleigh or Modal damping may be included.
  
• Loading histories can be completely arbitrary or mathematically defined (eg. sinusoidal or step distributions).
  
• The combined effects of up to 20 simultaneous load cases may be included, each with its own separate forcing function.
  
• The structure can be initially undeformed, or subject to some applied loading as calculated by the linear static solver.
  
• Initial velocities and accelerations may be applied.
  
• Deflection, velocity, force, acceleration, stress, strain, moment and curvature may be calculated at any saved step.
  

Harmonic Response

• Harmonic Response Analysis is used to calculate the dynamic response of a structure subjected to an oscillating or sinusoidally varying load. The loading may be applied at a particular frequency or over a range of frequencies. Structural damping may be included.
  
• For purely sinusoidal load variations, the harmonic solver can track any node and plot its response versus frequency.
  
• Up to 20 load cases may be applied simultaneously to the structure, each with a different phase angle.
  
• Both Rayleigh and Modal Damping may be applied.
  
• Maximum deflection, velocity, force, acceleration, stress, strain, moment and curvature may be calculated.
  
• Excitation may be either harmonic loads or harmonic base excitation.
  

Spectral Response

• Spectral Response Analysis is used for the analysis of structures subjected to seismic or random loads such as those experienced in earthquakes or vibrating machinery. The maximum response due to the applied spectrum is calculated. The spectral loading can either be via loads applied to the structure such as a blast load or by acceleration at the base of the structure as occurs in an earthquake. The results of a spectral analysis can be combined with linear static results to satisfy the requirements of many building design codes.
  
• Response Spectrum Analysis and Power Spectral Density (PSD) Analysis may be performed.
  
• Excitation spectra include Displacement Spectrum, Velocity Spectrum, Acceleration Spectrum, Load Spectrum.
  
• Both Rayleigh and Modal Damping may be applied.
  
• Maximum response including deflection, velocity, force, acceleration, stress, strain, moment and curvature may be calculated.
  
• Both CQC and SRSS methods are supported.
  

Linear Buckling

• Linear Buckling Analysis is used to calculate the load at which a structure is likely to fail due to elastic instability. The mode shapes are also calculated for each buckling mode.
  
• The buckling load and corresponding mode shapes can be calculated subsequent to a linear static analysis.
  
• Up to 100 modes can be calculated at any one time.
  
• An optional shift allows the calculation of higher modes.
  
• Buckling analysis can be performed on all element types.
  

Heat Solver

• Heat Transfer Analysis is an important part of many structural design problems. Often structures are subjected to significant thermal gradients as a result of manufacturing processes or the environment in which they operate. In these cases heat transfer analysis is used to calculate the temperature distribution in the structure which is then used as the loading condition for a linear static structural analysis. The heat transfer solver can consider conduction, convection and radiation modes of heat transfer.
  
• Full three dimensional potential flow may be performed.
  
• Both Steady State and Transient Heat Flow are available.
  
• Either Linear or Non-Linear material properties.
  
• The results at any time step can be passed to the Linear Static Solver for thermal stressing.
  
• Includes convection, conduction and radiation.
  
• The solver may be extended to solve other field problems such as electrostratics, magnetostatics, seepage, torsion, diffusion, etc.
  

Non Linear Static Solver

• Nonlinear Static Analysis is used for the analysis of structures where large deflection geometric nonlinear and/or material nonlinear behaviour is significant. The solver can also be used for nonlinear buckling and post buckling analysis.
  
• The Linear Static solver is extended by the updated Lagrange method to model non-linear behaviour.
  
• Both geometric and material non-linearity and combinations of these are possible.
  
• Reactions may be automatically calculated.
  
• Displacement control is available for snap through problems.
  
• Displacement, force, stress, strain, moment and curvature are automatically calculated for every increment.
  

INTERFACES ARE AVAILABLE TO THE FOLLOWING

DXF (AutoCAD)
IGES
NASTRAN
GFEM (Unigraphics)
SAP84
PATRAN

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For more information please contact us by e-mail: hsh@iperv.it

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