Transcript Integrating Revit Structure with Analytical Software

Integrating Revit Structure
with Analytical Software
Desirée Mackey
Martin/Martin, Inc.
Overview
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Introduction
Questions: When, How and Where to Start
Discuss five software packages: do’s, don’ts and tips
– RISA
– RAM
– Fastrak
– ETABS
– Robot
Comparison of the above packages
Open discussion
Objectives
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Wide view of software
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Unbiased comparison
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Focus on breadth of information
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Not focusing on details of the analysis software packages
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Have a little fun
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Discussion
Introduction – Revit Structure
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Revit Structure intended to:
– Convey 3D geometry
– Hold information
– Produce construction documents
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Revit Structure not intended to:
– Comprehensive structural analysis
– Create/produce calculations
– Intricate or complex design tasks
Introduction – Analytical Software
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Analytical software intended to:
– Analyze and/or design structural elements
– Accurately model/represent structural systems, loads, load paths
– Produce data/calculations
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Analytical software not intended to:
– Accurately convey all geometry, especially intricacies
– Produce construction documents
– Coordinate with other disciplines
Introduction – Revit Structure with
Analytical Software
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Meant for entirely different purposes
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A big task to seamlessly integrate
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Frequent updates of both creates a moving target effect
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Thrown together in the name of efficiency
Exporting to/from Analytical Software:
Questions to Consider
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Will an analytical software package be utilized in the design?
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Is there adequate interoperability?
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Was the Revit Structure model started/complete (enough) before needing
an analytical model?
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Was the Revit Structure model created with the intent to send to an
analytical software?
Exporting to/from Analytical Software:
Questions to Consider
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Does the project require a comprehensive analysis?
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Does the project require a specific analytical software?
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Does the analytical software support model exchanges with Revit enough
to make the process viable?
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If an analytical model is created prior to a Revit model, does that software
support exporting into Revit?
Exporting to/from Analytical Software:
Questions to Consider
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Does only part of the structure require analysis? If so, perhaps only part of
the model should be exchanged?
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Is the person creating the Revit model adept enough at Revit enough to
also create and maintain a viable analytical model?
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Is it more time/cost-effective to just have two separate people maintain two
separate models?
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Will the export be one-time, or will the model be “round tripped”? Given
the chosen analytical software, and its interoperability, does that affect the
decision?
Which Direction?
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Most analytical software packages recommend starting in Revit, but not all
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Always clean-up, so which software is easier to manipulate?
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Is the modeler/engineer more comfortable in one or the other?
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Which model is required to start first?
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Many factors to consider
When to Start in Analytical
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Analysis is required prior to starting the Revit model (or receiving the
Architectural model)
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The engineer is more efficient/comfortable in the analysis software
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Any specific required features, benefits, or limitations in either software that
make starting in the analytical more appropriate/efficient
When to Start in Revit
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Revit is more readily used and understood
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Revit likely used on every project, not every project requires analytical
software, and not the same software at that
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Revit seems to advance its analytical features often
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Important to make sure the geometry is properly represented
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Revit ultimately produces the construction documents
Preparing a Revit Structure Model for Export
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Pay attention to analytical lines
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Make sure analytical lines intersect properly
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Try to model on levels
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Consider how the levels are viewed in the analytical software
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Model level-to-levels, avoid unconnected heights
Preparing a Revit Structure Model for Export
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Consult the specifics of the intended software regarding how to handle
mulit-span or multi-level elements
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Use the “approximate curve” option for curved beams if practical
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Consider only updating sizes if updating geometry is not required
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Floors, slabs, and roofs generally are not well updated, so consider only
sending them one direction, one time
Preparing a Revit Structure Model for Export
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Only export what needs to be analyzed
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Create visibility filters, or use some other appropriate process to keep
track/keep organized
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If needed, model “dummy” sizes (ridiculously large or ridiculously small) to
help keep track of what has been designed
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The process is not perfect and there will be some amount of “clean up”
regardless of analytical software
Software Researched
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RISA Technologies
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RAM Structural System
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CSC Fastrak
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CSi ETABS
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Autodesk Structural Analysis – Robot Structural Analysis
Research Methods
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Documentation review
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Consultations with experts on each of the analytical software packages
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A few quick tests
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One basic model test
RISA Technologies
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RISA 3D – Three dimensional structural analysis for steel, concrete, masonry,
cold-formed steel, aluminum and timber
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RISA Floor – Comprehensive analysis for floor systems
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Link available as a free download
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Active Autodesk partner and determined to advance with Revit
RISA – Notable elements that work
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Curved beams
Beam Systems (members only)
Continuous/cantilevered beams
Braces (vertical only)
Trusses (members only)
Steel Joists
Floor slabs
Slab edges
Walls
Openings: by face or wall openings only
Isolated footings
Loads, Load cases, Load combinations
RISA – Notable elements that don’t work
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Openings: shaft and profile/boundary
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Foundation slabs
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Horizontal braces
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Rebar/hosted rebar
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Wall footings
RISA – Best Practices
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Only use start/end offsets to slope beams
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Use the z-direction offset to change beam elevations
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Outdated shapes/old structural shapes need to be mapped to current
shapes in the mapping file
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Slab edge locations are precarious – may change in Revit 2013
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Openings require opening framing to transfer properly
RISA – Best Practices
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RISAFloor requires multi-story columns to be modeled floor-to-floor, and
continuous/cantilevered beams need to have each segment modeled
separately
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Check the merge tolerance settings and joint coordinates
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Be careful about changing node coordinates in RISA
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Reactions come back into Revit as separate parameters, RISA provides tag
families
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Don’t bother with the Revit analytical checks, use the ones in RISA
RAM Structural System
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Complete analysis and design of steel and concrete
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3D model, level based, and individual modules for different
elements/materials
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Bentley software, but Bentley actually creates many add-ons for Autodesk
software
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Link available as a free download
RAM – Notable elements that work
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Steel Joists
Braces
Trusses (members only)
Beam systems (members only)
Walls (bearing and structural combined only)
Openings: by face or wall openings only
Isolated footings
Continuous/cantilevered beams (requires special setting)
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Many elements work but can be exchanged once only, cannot be
updated, also will likely only transfer one way (either Revit to RAM or RAM
to Revit)
RAM – Notable elements that don’t work
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Loads, Load Cases, Load Combinations
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Openings: shaft and profile/boundary
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Foundation slabs
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Walls set to shear
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Rebar/hosted rebar
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Curved beams
RAM – Best Practices
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Set the reference level for braces to the top level to which they frame
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Frame braces into beams and columns that are set to lateral
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Default mapping of shapes are set to out-of-the box families
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Loads just generally don’t work well
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“Member supports” in the structural settings >>Analytical Model Settings tab
must be checked on to detect cantilevered members
RAM – Best Practices
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Multi-story columns in Revit are broken up at the levels in RAM
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Isolated footings have to be perfectly centred on columns for the
information/sizing information to exchange properly
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Continuous beams need to be modelled as separate segments between
supports to be imported properly into RAM
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If exporting from RAM to Revit, export to a Revit template, not to a blank
project
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For slopped roofs, model flat, or at least all on one level before sending to
RAM
CSC Fastrak
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Complete analysis and design of steel
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Originally a British software, now expanded into US codes
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“Seamless” communication with Revit Structure
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Link available as a free download
Fastrak – Notable elements that work
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Beam systems (members only)
Curved beams (only if curve is approximated)
Braces (vertical only)
Steel Joists
Trusses (Revit to Fastrak only, members only)
Floor slabs (mapping setting required)
Stiffeners/plates
Fastrak – Notable elements that don’t work
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Loads, Load Cases and Load Combinations
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Openings: shaft and profile/boundary
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Section/size properties – attribute sets
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Walls
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Rebar/hosted rebar
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Wall Footings
Fastrak – Best Practices
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Levels are required at the top of steel level
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Attributes have to be assigned to all the elements once imported into
Fastrak
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Revit model has to be saved immediately after exporting to Fastrak
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In Fastrak, slabs must be supported on all sides by a member
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If exporting from Fastrak to Revit, the structural usage will have to be
adjusted once in Revit such that girders/beams/joists will have the correct
line weights
Fastrak – Best Practices
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View filters and the “track changes” command to track changes
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If analytical lines are adjusted away from auto-detect, the same
adjustment must be used at both ends of the member
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Foundations are created under EVERY column when transferring into Fastrak
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Revit and Fastrak models can be updated simultaneously, but any changes
in one will override the other when exported
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Reactions exported only for a fully completed design model, and only if
members are designated as “gravity only” design. A shared parameter
must be added to use a Revit tag
CSi ETABS
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Structural and earthquake design specialty
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Many modules
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Information is hard to find, and what is there is outdated. Company doesn’t
seem to promote their interoperability with Revit
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Link available on a paid subscription
ETABS – Notable elements that work
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Curved beams (only if curve is approximated)
Steel Joists (come through as beams)
Walls
Floor Slabs
Isolated Footings
Braces (vertical only)
Openings: wall, shaft and by face
Loads, load cases and load combinations (some limitations)
ETABS – Notable elements that don’t work
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Openings: shaft and profile/boundary
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Diaphragm designations
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Trusses
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Rebar/hosted rebar
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Wall Footings
ETABS – Best Practices
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Diaphragms will have to be defined once in ETABS
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Import/export dialog boxes appear during the import/export process
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If a parametric family has an unrecognized type, ETABS will create a
corresponding shape
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Windows vista bugs
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End release updates are occasionally “buggy”
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Material updates not transferred from ETABS to Revit
ETABS – Best Practices
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Z-justification and start and end offset parameters don’t always translate
properly
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Only openings completely inside a wall or floor will be transferred
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In-place families are imported into ETABS as frame members
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Elements can be deleted upon importing/exporting, but only if the entire
model is exchanged
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Load combinations can be exchanged once, but cannot be later updated.
They can, however, be deleted and replaced
Autodesk Structural Analysis – Autodesk 360 –
Robot Structural Analysis
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Autodesk 360 structural analysis in the cloud, or local analysis using Robot
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Formerly Project Storm
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Large analytical updates with each of the last couple of releases
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Link native in Revit
Robot – Notable elements that work
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Curved beams
Beam Systems (members only)
Braces (vertical only)
Trusses (members only)
Steel Joists
Floor slabs
Slab edges
Walls
Isolated footings
Wall footings
Loads, Load cases, Load combinations
Rebar/hosted rebar
Robot – Notable elements that don’t work
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Foundation Slabs
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Horizontal Braces
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Families/family types that don’t already exist in the Revit project
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Wall Footings
Robot – Best Practices
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Static analysis only if using 360
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Differentiate the start and ends of members
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The same person will likely model both the Revit and Analytical model, so
staff appropriately
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Multi-span members will be split into separate members once in Robot
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Use hosted area loads
Robot – Best Practices
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Send and update Revit/Robot models from Analyze tab within Revit
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Upon updating the Revit model, there is an option to keep updated
elements selected
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Robot will analyze and exchange some connections: end plate and
column flange connections
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Sloped planes/framing are supported
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Duplicate nodes will be created if analytical lines are not modeled properly
A little experimenting...
What to model...
The model...
The model...
Model Details
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Revit Structure 2012 – no 2013 links available yet
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Steel and concrete members
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Walls, beams, columns, foundations, braces
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Precise analytical model
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Loads, load cases and load combinations applied in Revit – a variety
– Pigs modeled as point dead loads
– Birds modeled as point and line live loads
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Followed as many “best practices” for as many of the software packages
as possible
The model...
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Differentiated ends of the
analytical lines to help
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Best I could do with the roof
slab in Revit 2012 – aligns
vertically with the members
but not always in plan
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Floors easier to align
properly
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Precise intersections
The model...
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Intersections with many members
were harder, especially with
braces
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Used snapping shortcuts
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Definitely more time consuming
to make both the geometry and
the analytical correct
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Occasionally deleted and
redrew a member instead of
trying to fix it
The model...
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Made pigs dead loads
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Made birds different live
loads
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Made custom load
combination loosely based
on IBC load combinations
The model...
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Changed object styles to be
able to see loads and
foundations easier
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Changed colors to match
pig and bird colors
The model...
The model...
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All links under External Tools
or their own button in the
Add-Ins Tab
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Robot under Analyze Tab
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Load ETABS last
RISA
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Simple, easy export dialog box
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Most basic options available
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No intricate details/settings
available upon export
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Exchange file should be saved in
the same location as the base Revit
and analytical files
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Browse to mapping file separately
but seems less likely to need it
Revit to RISA 3D
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Elements, nodes, connections, end
releases come through well
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All loads, load cases, load
combinations came through
except for line loads
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Walls not perfect – rounding errors
with nodes create a non-planer
error
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Analysis ran immediately upon
import
RISA 3D back to Revit
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Everything came back in the way it
left
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Walls not perfect – changes in RISA
to fix the non-planer error caused
some small movement and an
“element slightly off axis” warning
Revit to RISA Floor
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Elements, nodes, connections, end
releases come through well
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All loads, load cases, load
combinations came through
except for line loads
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Sloped roof was modeled with
different levels, so each level
came through separately and roof
was flattened
RAM
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Simple, easy export dialog box
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Few options available upon export
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Exchange file should be saved in
the same location as the base Revit
and analytical files
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Error log reports what didn’t transfer
– loads caused a problem here
Revit to RAM
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Elements, nodes, connections, end
releases come through well
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Loads didn’t really seem to come
through at all
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Same level issue as RISA Floor –
sloped roof was split into levels
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If mapping file not set to custom
families, or if out-of-the-box
families not used in the Revit model
export will fail entirely
RAM back to Revit
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Most elements returned to Revit
without issues
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Loads that were originally in Revit
were not overridden
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Material properties seemed to
change a bit in that the graphic
displays in Revit were no longer the
same
Fastrak
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User-friendly import/export dialog
boxes
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Many intricate options available
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Reports mapping and other issues
upon export and allows the user to
fix the problems
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Exchange file should be saved in
the same location as the base Revit
and analytical files
Fastrak
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Prompts for information about fist
time export or updating the mode
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Prompts for a selection of what
elements to export
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Reports mapping
error/unrecognized shapes and
prompts for a solution
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Individual mapping files for each
type of element/material/family
Fastrak
Fastrak
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Prompts to save exported file
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Warning log explains what
elements were not transferred
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Save Revit file immediately after
export to maintain link with Fastrak
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Two-Step process – Fastrak has to
be opening and then Revit file
imported
Revit to Fastrak
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Elements, nodes, connections, end
releases come through well
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Only steel members come through,
but Fastrak doesn’t analyze
concrete
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Attribute sets will now have to be
assigned in Fastrak
Fastrak back to Revit
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Again, two-step process of
exporting an exchange file and
then importing
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Opportunity to “ignore position” of
elements
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Good return of objects, many
material properties were changed
ETABS
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Simple string of dialog boxes
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Opportunity to select which
element to export
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Error dialog prompting mapping
clarifications
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Two-step process
Revit to ETABS
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Elements, nodes, connections, end
releases come through well
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All loads, load cases, load
combinations came through
except for line loads
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Surprisingly clean export, model
could complete an analysis
immediately upon import
ETABS back to Revit
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Upon Importing back to Revit,
dialog prompts for options of what
to import/update
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Everything came back in the way it
left, except the line loads
appeared to change slightly
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Again, surprisingly clean with few
warnings/errors
Robot
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Native button in Revit – Analyze tab
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Simple dialog, no intricate options
or prompts
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Some options in “send options”
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Launches Robot, but not demo
version
Revit to Robot
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Elements, nodes, connections, end
releases come through well
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Loads, load cases, load
combinations came through
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Analysis ran immediately
Robot back to Revit
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Upon Importing back to Revit,
dialog prompts for options of what
to import/update
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Everything came back in the way it
left
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Options to select the updated
elements
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Except for the separate window for
Robot, almost seems native to Revit
Conclusions
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Everything did generally better than expected
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Software generally exchanged the elements they design
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RISA, ETABS and Robot exchanged the most elements and properties with the
fewest errors
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Fastrak was the most comprehensive and they claim to be the best exchange,
but very deliberate…so is all this just automatic in the other software packages
so an illusion that Fastrak is better?
Conclusions
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Only one roundtrip, would the results be different if I did more?
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Too much “clean-up” required for Fastrak, but if it is better with round tripping
then it may be worth it
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Applying loads in Revit wasn’t always easy, and not as easy as in the
analytical packages
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Look out for Autodesk and Robot to advance analytically in the coming years
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Choose software based on engineering needs
Discussion?
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Experiences with any of these software packages on projects?
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What was good? What was bad?
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Lessons learned?
Questions?
Email:
Blog:
Twitter:
[email protected]
bdmackeyconsulting.com/blog
@RevitGeeksWife
Desirée Mackey
Martin/Martin