Strand7 Software: In Detail: Feature Summary

Strand7 summary of features

Environment
Data files
The entire Strand7 data file is stored in a single .ST7 file. This is a compact binary file that makes book-keeping, maintenance and model archiving much easier. Strand7 results are also stored in single files - for example, linear static analysis results are stored in a single .LSA file. Strand7 result files are significantly smaller than those typically generated by other FEA software.

Configuration
Strand7 is highly user-configurable. For example, you can set a wide range of display options, such as colours, lighting and perspective. You can also configure file locations, which is useful in a networked environment --- you can keep model files on a shared network drive while keeping temporary files on a faster local PC drive.

Context-sensitive help
Press F1 at any time to view context-sensitive help. Strand7 has a comprehensive, hyperlinked on-line help system that includes tutorials, modelling techniques and theory.

Multiple model processing
Strand7 allows you to open multiple models simultaneously. You can exchange data graphically between models using copy/cut-and-paste tools. You can solve more than one model at the same time, even while editing and post-processing other models.

Physical units
Strand7 is fully units-aware. You can set and modify all the physical units used by Strand7. These units do not have to be consistent - should you so desire, you can mix metres and kilograms with feet and pounds.

Language support
Strand7 supports a range of different languages including Chinese and Japanese.

Building models
Unlimited entity creation
Strand7 does not impose any limits on the number of nodes or elements, or the number of equations. Any limitations imposed are generally hardware-related. For example, the maximum number of load cases is 32000, which is virtually unlimited for real modelling purposes.

Real-time dynamic rotation
You can rotate, scale and pan the entire model in real-time, using only the mouse. This feature is available in wireframe mode or fully-shaded solid mode, and doesn't require special graphics cards or graphics acceleration. You can also use it to dynamically change the displacement scale when looking at results. Simply click and drag to set the required displacement scale.

Groups
Use element groups to organise and manage large models. Create a set of groups, which can be organised into an appropriate hierarchy of your choice. Then, assign elements to these groups. You can show and hide elements, select elements and view results by group.

User-defined beam sections
Design your own beam cross-sections. Strand7 renders these in 3D for both pre-processing and post-processing, so you can create sections of arbitrary shape and immediately view them in the graphical editor. Strand7’s section calculator generates exact torsional constants, shear areas and warping constants whenever you create a user-defined section.

Verification tools
Strand7 offers many mesh verification tools, like free-edge display. You can contour many quantities, including aspect ratio, volume and applied pressure and temperature.

General equation input
Enter numbers as mathematical expressions. For example, you can assign node forces and plate pressures as functions of position.

Undo and redo
Strand7 offers a powerful unlimited undo capability. You can undo all modelling changes, no matter how complex or how many entities are affected. A redo function lets you reverse the previous undo.

Automatic mesh generation
Strand7 includes automatic mesh generation tools, working directly from geometry. You can automatically generate 4-node and 8-node plates from 2D regions, and 4-node and 10-node tetrahedra from 3D regions. Strand7 provides powerful geometry input tools for the automatic mesher. Alternatively, you can import CAD-generated data for more advanced CAD geometry. IGES, STEP, AutoCAD's DXF format and Spatial's ACIS format are supported. And to ensure you can generate a good quality mesh, Strand7 includes a suite of geometry cleaning, healing and defeaturing tools.

User-defined coordinate systems
Define your own coordinate systems, which can be rectangular, cylindrical, spherical or toroidal. Local coordinate systems can greatly simplify model-building and results extraction.

Plate thickness display
Strand7 can render plate element thicknesses. This lets you clearly visualise the relative thickness of each plate, and helps you check for errors. You can easily contour results --- such as stresses --- on both plate surfaces simultaneously.

Sub-modelling
Sub-modelling allows you to extract parts of a model and save them as separate files, with boundary displacement conditions automatically enforced as constraints. This lets you perform local mesh grading without having to re-solve the entire model.

Multiple freedom cases
You can generate results for multiple sets of freedom conditions in a single model.

Investigating results
Solvers
Strand7 includes the following solvers: Linear static Natural frequency Buckling Nonlinear static Linear and nonlinear transient dynamic Spectral and harmonic response Linear and nonlinear steady-state heat transfer Linear and nonlinear transient heat transfer Strand7 also provides the following data: Bill of materials for each group or sets of groups Inertia properties for each group or sets of groups

Cutting planes
You can specify arbitrary cutting planes in brick models, and view stress contours on these planes.

Load case combinations
You can create a virtually unlimited number of load case combinations. Change these combinations at any time without having to re-solve the model.

Searching
Use searching to locate certain result values, or results exceeding a certain value.

Result contours
Strand7 helps ensure you detect all stress concentrations. You can contour stress that has been: averaged, not averaged, averaged only across elements with the same material, and averaged only across elements in the same plane (for plate elements).

Enveloping
For problems with multiple load cases, or transient problems with many time steps, you can display the envelope of maximum results over every load case or time step.

Listings and reporting
List, sort, filter and print result data in report format. You can filter results by group and property, and view results for only those entities selected in the graphical editor. For more detail, request plate and brick results at nodes and Gauss points, and beam results at many positions along each beam.

XY plots
You can generate an XY plot of virtually any result parameter between two points on the model. Simply click on two nodes to specify the desired path.

Elements and attributes
Nodes
Strand7 includes the following node attributes: Forces Moments Restraints (in any coordinate system) Mass (translational and rotational) Stiffness (translational and rotational) Temperature (constant and time-varying) Damping Velocity and acceleration Response variables Heat source

Beam attributes
Strand7 includes the following beam attributes: End-releases (full and partial release) Offsets, local angles and arbitrary shear centres Taper Temperature gradients in principal axes Point forces and moments (local and global) Constant and linear distributed loads (local and global) Distributed elastic supports Distributed non-structural mass Stiffness and mass scaling Pre loads (tension or strain) Response variables Attachment Thermal flux Convection and radiation coefficients Heat source
For pipe elements, Strand7 includes the following attributes: Pipe radius Internal and external temperature Internal and external pressure
For cable elements, Strand7 includes the following attribute: Free length

Plate attributes
Strand7 includes the following plate attributes: Offsets and local angles Edge release Pre-stress or pre-strain Temperature gradients through the thickness Point forces and moments Surface pressure and shear (local and global) Edge pressure, edge shear and edge normal shear Surface and edge elastic supports Distributed non structural mass Response variables Soil in-situ conditions Reinforcement layouts Attachment Thermal flux Convection and radiation coefficients Heat source

Brick attributes
Strand7 includes the following brick attributes: Local axis orientation Elastic support Pre-stress or pre-strain Point forces Pressure (local and global) Shear Response variables Soil in-situ conditions Attachment Thermal flux Convection and radiation coefficients Heat source

Materials
You can define your own materials or extract them from a user-configurable materials library. Material models supported by Strand7 include: Isotropic Orthotropic Anisotropic Laminate Rubber Soil User-defined
To define nonlinear material behaviour, you can specify stress vs strain, force vs displacement, moment vs curvature and moment vs rotation tables. Yield criteria supported by Strand7 include: Tresca von Mises Mohr-Coulomb Drucker-Prager Principal stress

Beam elements
Strand7 includes the following beam types: Standard beams Trusses Cutoff bars Point contacts Springs and dampers Cables Connections User-defined beams

Plate elements
Strand7 plates may be Triangular (3 or 6 nodes) Quadrilateral (4, 8 or 9 nodes) Included are the following plate types: 2D plane stress 2D plane strain Axisymmetric Plate/shells (thick and thin) Shear panels 3D membranes

Brick elements
Strand7 bricks may be: Tetrahedra (4 or 10 nodes) Pyramids (5 or 13 nodes) Wedges (6 or 15 nodes) Hexahedra (8, 16 or 20 nodes)

Links
Strand7 includes the following link types: Sector symmetry Rigid links Pinned links Master/slave links Coupling links Shrink links Attachment links Multi-point links

Documentation
In addition to the context-sensitive on-line help, the following documentation is available: Using Strand7 is an easy to read, concise manual, which covers all the basics of Strand7. It is normally used as a getting started guide. The Strand7 Verification Manual contains hundreds of fully documented problems, complete with reference solutions and comparisons with Strand7 solutions. The actual model files are also distributed as part of the Strand7 installation for user reference and quality assurance reasons.