Features for structure modeling and analysis.
A full description of all the features is available in the other Help sections.
Seismic load analysis using Response Spectrum approach has been extended with the following national codes:
Australia AS 1170.4 - 2007 Earthquake actions in Australia.
Canada NBCC 2010 National Building Code of Canada 2010
New Zealand NZS 1170.5:2004 Earthquake actions - New Zealand.
New codes are the default codes for New Zealand, Australian and Canadian regional settings, and are settled automatically after selecting any of these regional settings in Preferences dialog. New codes may be chosen as well individually inside Job Preferences dialog.
Analysis parameters are defined using standard seismic parameters dialogs which are displayed while defining the new seismic analysis load case, or inspecting properties of existing (defined) seismic load cases. Parameters dialog displays the code name in the header, as is shown on the picture below for exemplary New Zealand code dialog.
The Equivalent Lateral Force method was developed to allow seismic analysis according the following national codes:
Australia AS 1170.4 - 2007 Earthquake actions in Australia.
Europe EC8 1998-1:2005 Eurocode 8. Design of structures for earthquake resistance
United States ASCE 7-10 Minimum Design Loads for Buildings (recalled in the IBC 2009 requirements)
The Equivalent Lateral Force method is an alternative (simplified) approach for determining distribution of seismic base shear force on the height of regular, multistory building. This method is the most commonly used design procedure allowing determination of design seismic forces by a linear elastic static analysis of the structure.
Applying this approach needs definition of a load case of a separate analysis type: Seismic (Equivalent Lateral Force Method). Seismic codes for this option are selected independently on the seismic analysis codes defined in Job Preferences.
Depending on directions and eccentricities definition series of 'static - seismic' load cases are generated. X/Y components of direction vectors are understood as additional "multipliers" for the calculated horizontal forces on each direction.
When mass eccentricities (5% displacement of the center of mass) are defined on both directions load cases are generated for all combinations of mass displacements but on both orthogonal directions at the same time.
Acting forces for the load cases created while Equivalent Lateral Force Method analysis is defined are generated during structural analysis phase. This is why they cannot be seen before launching structure analysis. To be displayed graphically on the screen it is needed to check the option "forces generated automatically" in the Display dialog. Their tabular values may be seen on "Pseudostatic forces" table.
The seismic design story shear is distributed among the story nodes reflecting the mass distribution. When a floor is modeled by diaphragm (no internal nodes are defined) the shear force is attached to its gravity center.
The structure model has got to stories defined, however they are understood more as geometry division and do not need to have real floors presented (frame structures may be analyzed as well)
The provisional code according to which calculations were performed was replaced with the final code.
Imposed action characters and combination factors defined in AS/NZS 1170.0:2002 are now taken into account when the above code is selected in Job Preferences (section Design codes\Loads) or in Automatic Combinations dialogs.
It is possible now to generate automatically load combinations according to this code.
New regulation file conforming National Building Code of Canada 2010 is now available. This regulation governs when NBCC 2010 design code is selected.
New combination factor for Wind load and other changes introduced by the new code edition ASCE/SEI 7-10 were incorporated into regulation files for ASD and LRFD approaches.
Two new regulation files for automatic generation of combinations have been added, presented in the list of load combinations under the names: LRFD ASCE 7‑10 and ASD ASCE 7‑10.
When updating a model in the Autodesk® Revit® software after changes made by Autodesk® Robot™ Structural Analysis Professional 2015 software, the corresponding floors analytical models are compared. If any difference is detected, the link attempts to update the Revit floor analytical model by setting new analytical model curves.
Autodesk® Revit® 2013 introduces an analytical link (an element connecting 2 separate analytical nodes). When sending model from Revit to Robot analytical links are converted and transferred to Robot as rigid links.
Japanese materials - concrete and steel grades - were updated to correspond to the current code requirements and market state. Similarly database with H and I families of hot-rolled steel section was updated.
Seismic modes are now combined much faster, due to optimization and refactoring of the mathematical operations on vectors with large zero numbers. Observed acceleration varies from 2 up to 8 times depending on a model.
Smaller memory consumption and file size as well as quicker model generation are observed after optimizing distributed loads defined on claddings.