University at Buffalo, Departement of Civil, Structural, and Environmental Engineering


A Computer Program for Seismic Inelastic Structural Analysis

Developed at the  University at Buffalo - the State University of New York, IDARC was first introduced in 1987 for the purpose of analyzing earthquake damage in multistory, reinforced concrete buildings. Since then, numerous enhancements have been added, including the ability to analyze a wide variety of structures, structural materials, and, most recently, structural damping devices. New features are continuously being added to IDARC, while three dimensional and bridge specific versions are currently being developed.  Moreover "sister" programs such as NSPECTRA for calculating nonlinear inelastic response spectra were also developed

The program IDARC is distributed free, with corrections and minor updates, as part of Membership in a Users Group. For information on membership check the appropriate button above. Non-members can also get a version of the program executable free, but without any support.

The purpose of this web site is to keep you up-to-date on the latest reports, enhancements, Memberships, as well as to help you resolve any problems you may encounter while using IDARC.

NEW IDARC 2D Version 7.0 Available!
IDARC 2D Version 7.0 has been released! The following features are new in this version:
  • Corrections of all the other versions. +
    • 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
    • Additional 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

See also the updated features page
Go to the download page to get this new version. Current user group members, go to the members download page for additional material.

button.GIF (874 bytes)Latest Reports
button.GIF (874 bytes)Memberships
button.GIF (874 bytes)FAQ

If you are not familiar with the program's capabilities, feel free to download the most recent freely available version of the executable files and examples. If you would like to receive the most up to date version of the program, a copy of the source code or technical support, you can find the relevant information in the IDARC Users Group page, or you may contact:

Professor A. M. Reinhorn
Department of Civil Structural and Environmental Engineering
University at Buffalo
135 Ketter Hall, Buffalo, NY 14260-4300
Phone: 716-645-2839
Fax: 716-645-3733

The creators of the IDARC program are:

Andrei M. Reinhorn, PhD University at Buffalo-SUNY
Yong J Park, PhD Deceased
Sashi Kunnath, PhD University of California at Davis
Rodolfo Valles-Mattox, PhD Consultant, Mexico City, Mexico
Roy Lobo, PhD Consultant, Sacramento USA
Alok Madan, PhD Indian Institute of Technology, New Delhi
M. (Siva) Sivaselvan, PhD University of Colorado, Boulder
Hwasung Roh, PhD University at Buffalo- SUNY