Program Features

IDARC is a computer program for nonlinear structural analysis that allows many aspects of concrete behavior to be explicitly modeled. Many of the primary developments and enhancements to this program have linked experimental research with analytical developments. Details of the program's features and references to the analytical basis for them can be on the Introduction page. Additional information regarding the availability of the program can be found in the FAQ and on the Users Group page.

IDARC 2D is constantly being upgraded and improved. The latest releases include the following features and additions:

Version 7.0:

• Addition of new rocking column element
• New nonlinear-elastic-cyclic model with either negative or positive stiffness
• Added white-noise ground motion analysis for horizontal and vertical shaking
• Added story velocity output
• Expanded limits of numbers of elements and input wave data
• Added special spring hysteretic model for wire base isolation element
• New “case studies” for examples and program validation
• Expanded Users Group and internet site support
• Corrections
  • Angle of hysteretic damper/braces and corresponding horizontal force definition
  • Vertical ground motion interaction
  • P-delta effects
  • Negative ultimate moment of rotational spring elements

Version 6.1:

• Corrections of all the other versions.
• Addition of perforated walls, shear-bending columns and walls.
• Correction of sign convention for visco elastic dampers system.
• Correction of iteration process for the solution of multi-infill panel elements.

Version 6.0:

• Addition of perforated walls elements
• Addition of inelastic shear-bending columns and beams

Version 5.5:

• Polygonal and Smooth Hysteretic Models for beams, columns and walls
• Option of Linear or Constant flexibility distribution in yield zone for spread plasticity model
• Rotation springs moved to beam and column ends to form combined element to model connection behavior

Version 5.0:

• New unified multilinear and smooth  hysteresis models with degrading characteristics.
• Concentrated plasticity model for beams and columns.
• Analysis beyond first onset and failure
• Computation of plastic rotations in beams and columns
• Enhanced model adaptive "pushover" nonlinear statis analysis
• New damage indicators

Known Problems:

The following is a list of some known problems and inconsistencies in our software, the accompanying example files, and in the documentation. We are working to correct these problems, and we will release updates to the program as soon as they are fixed.

• Rotational spring element is not checked.