CASSETA Tools – CSi ETABS Utility Application

Description

Simple utility application for manipulating ETABS models, with some limited functionality for manipulation of CSi SAFE models. Although initially envisaged to help with defining and running basic batch processes with CSi ETABS, which it still does, the application has grown over time and now includes an array of tools for directly modifying currently open ETABS and/or SAFE models. Current tools include:

Batch tools

• Graphical user interface for adding/removing model files from the batch process.
• For each of the models in the list:
  • Adjust area objects stiffness modifiers (walls and floors), separately for area object properties modifiers and area object elements modifiers.
  • Adjust frame objects stiffness modifiers, which currently includes properties and elements with beam or column orientation, excluding bracing elements.
  • Add non-linear static load cases and load combination for long term cracked analysis of floors (This is only applicable to ETABS Ultimate).
  • Assign cracking analysis overwrites to floor area objects.
  • Remove design strips from the model (in case models need to be submitted to a third party that does not have CSi ETABS Ultimate license).
  • Move model elements to a different location by specifying an X, Y, Z vector.
  • Move model grids to a different location by specifying an X, Y, Z vector.
  • Run analysis.
  • Run design for concrete frame elements and concrete floor elements (Note: Concrete wall design is currently not supported through the CSi’s open API).
  • Log is kept for each command executed during the batch process and can be exported to a text file for assessment and/or review.

Additional tools

Some additional tools for directly adjusting currently open model include:

• Application of pinned and rigid supports to the lower-most walls and columns.
• Remove non-linear static cases from the model (in case models need to be submitted to a third party that does not have CSi ETABS Ultimate license).
• Remove column design strips from the model.
• Remove middle design strips from the model.
• Add special joints for defining one-way shear design strips. The strips are located at an effective depth, d, away from column faces, where d is automatically calculated from the floor area object to which the column ‘belongs’. The points can be simultaneously added to multiple columns of different sizes.
• Calculate appropriate widths for one-way shear design strips, on the basis of column width in a certain direction and thickness, h, of the floor slab. Currently, the design strips need to be drawn manually, with the help of previously added one-way shear design strip points. This is due to lack of support for creation of design strips through CSi’s open API.
• Remove defined one-way shear strip points with a click of a button.
• Delete loose link objects from the current model. Loose links are those connecting to a single frame or area object, with the other end not connecting to anything else.
• Delete all link objects from the current model.
• Check for area objects without a pier assignment. The check can be carried out for all wall objects, or for those without a spandrel assignment.
• Check for area objects without a spandrel assignment. The check can be carried out for all wall objects, or for those without a pier assignment.
• Check if base level and top of structure level are used in the definition of automatic seismic load patterns.
• Define and assign top and bottom stories and apply those to all automatic seismic load patterns with a single click of a button.
• Define seismic response and seismic importance factors for checking dynamic response spectra base shear to equivalent static force base shear ratios. A target ratio can be defined. Required acceleration scaling factors are calculated and can, optionally, be automatically applied to the model with or without running subsequent analysis to take into account revised scaling factors.
• Define basic wind load parameters and amend all currently defined automatic wind load patterns to suit with a single click. Currently, the application supports modification to the following parameters: wind speed, exposure type, topographic factor (kzt), gust factor, directionality factor (kd), top story, bottom story and parapet height.
• Define a naming convention for frame objects and check if the property definitions in the current model conform to the defined convention. The convention is defined by specifying a pattern based on property attributes, e.g., frame dimensions, assigned materials, reinforcement bar numbers and sizes, etc. Exclusion filters can be defined so that the application checks only those properties that match defined filter criteria. Equally, conditional naming pattern attributes can be defined as an if/then attribute, e.g., if torsional stiffness modifier is of certain value (or below or above a certain value), then add ‘T’ to the frame property name. With this tool, as an example, all columns can easily be renamed to C500X700C60/7&5T20, or beams to B400X600C48T. This tool is available for both ETABS and SAFE models.
• Create staircases area objects by selecting points at the corners of the core. Currently, only 4 sided cores are supported. Points on multiple levels can be selected for a quick creation of complete staircase structure within the core. Staircase structure currently comprises of floor-level landing slab, mid-level landing slab and two inclined area objects spanning between floor-level, mid-level, and a floor at a level below.
• Select all staircase area objects with a single click, which may be useful for application of load patterns and load cases. Landings and staircase flights can be selected separately, or all together.
• Deselect all staircase area objects (or separately landings and staircase flight slabs) from the current selection.
• Delete staircase area objects from the model with a single click. Landings and staircase flights can be deleted separately, or all together.
• Creation of ramp area objects based on defined slope and height, or by selection of frames at start/end of the ramp. Curved portions of ramps are automatically triangulated.
• Copy concrete materials (including defined steel reinforcement bar materials) from currently open ETABS model to the currently open SAFE model.
• Export floor elements, walls, columns and loads to RAM Concept for further slab analysis.

In its current state, the application mostly supports ETABS, with limited tools included for manipulation of SAFE models. However, the methods developed are adaptable for application to CSi SAFE, and this something that is being worked on intermittently, as the application develops.

The software is currently in its Beta phase.