IDARC -- Introduction

Introduction

The computer program IDARC (2D) was conceived as a platform for nonlinear structural analysis in which various aspects of concrete, steel and other materials behavior can be modeled, tested and improved upon. Program development and enhancements have been primarily to link experimental research and analytical developments.

The computer program IDARC (2D) was introduced in 1987 as a two-dimensional analysis program to study the non-linear response of multistory reinforced concrete buildings. The original program released included the following structural element types:

Column Elements
Beam Elements
Shear Wall Elements
Edge Column Elements
Transverse Beam Elements

Column elements were modeled considering macromodels with inelastic flexural deformations, and elastic shear and axial deformations. Beam elements are modeled using a nonlinear flexural stiffness model with linear elastic shear deformations considered. Shear wall include inelastic shear and bending deformations, with an uncoupled elastic axial component. Edge column elements were introduced considering only inelastic axial deformations. Transverse beam elements, that have an effect on the rotational deformation of the shear walls or beams to which they are connected, are modeled using elastic linear and rotational springs.

One of the significant features incorporated in the program, to implement inelastic behavior in the macromodels, is the distributed plasticity model implemented with the flexibility matrix approach that replaced the commonly used hinge model developed for steel frames. The hinge model is not suitable for reinforced concrete elements since the inelastic deformation is distributed along the member rather than being concentrated at critical sections (Park et al., 1987). However for sake of compatibility with other program and to model plastic characteristics a concentrated plasticity model was also developed. To trace the hysteretic response of a section a three parameter model was developed. Through the combination of three basic parameters and a trilinear skeleton curve stiffness degradation, strength deterioration and pinching response can be modeled. Hysteresis models for tracing the cyclic dynamic behavior were developed. Two of the models, a polygonal model and a smooth model have various degrading features that occurr during reversible loading.

The original version of the program included the damage model developed by Park and Ang (1984) to provide a measure of the accumulated damage sustained by the components of the structure, by each story level, and the entire building. This damage index included the ratio of the maximum to ultimate deformations, as well as the ratio of the maximum hysteretic energy dissipated to the maximum monotonic energy, therefore capturing both components of damage.

The original release of the program consisted of three parts (Park et al., 1987):

System identification: static analysis to determine component properties and the ultimate failure mode of the building.
Dynamic response analysis: step by step inelastic dynamic analysis.
Substructure analysis and damage analysis: analysis of selected substructures, and comprehensive damage evaluation.

Later versions of the program included:

The addition of a fiber model routine to automatically calculate the envelope curve of columns, beams and shear wall elements.
A quasi-static, or pseudo-dynamic, analysis module for comparisons with experimental tests.
Addition of P-Delta effects in the program.

After the releases of the program, Version 4.0, a number of enhancements were made to later releases:

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

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.

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

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

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

Applied Technology Council (1995), "Guidelines and Commentary for the Seismic Rehabilitation of Buildings," 3 Volumes, ATC-33.02, 50% Submittal, Second Draft, Federal Emergency Management Agency.
Habibullah, A. (1995), "ETABS v6.0: Three Dimensional Analysis of Building Systems," User's Manual, Computers & Structures Inc.
Li, C., and Reinhorn, A. M. (1995), "Experimental and Analytical Investigation of Seismic Retrofit of Structures with Supplemental Damping: Part II-Friction Damping Devices," Report No. NCEER-95-0009, National Center for Earthquake Engineering Research, State University of New York at Buffalo.
Naeim, F., Skliros, K., Reinhorn, A. M., Sivaselvan, M. V.,(1998). "Effects of Hysteretic Deterioration Characteristics on Seismic Response of Moment Resisting Steel Structures", JAMA Report, John A. Martin & Associates, Inc., Los Angeles.
Park, Y. J., Reinhorn, A. M., and Kunnath, S. K. (1987), "IDARC 2D: Inelastic Damage Analysis of Reinforced Concrete Frame - Shear-Wall Structures", Technical Report NCEER-87-0008, State University of New York at Buffalo.
Park, Y. J., Ang, A. H.-S., and Wen, Y. K. (1984), "Seismic Damage Analysis and Damage-Limiting design of R/C Buildings", Civil Engineering Studies, Technical Report No. SRS 516, University of Illinois, Urbana.
Reinhorn, A. M., and Li, C. (1995b), "Experimental and Analytical Investigation of Seismic Retrofit of Structures with Supplemental Damping: Part III-Viscous Walls," Report No. NCEER-95-0013, National Center for Earthquake Engineering Research, State University of New York at Buffalo (in press).
Reinhorn, A. M., Li, C. and Constantinou, M. C. (1995a), "Experimental and Analytical Investigation of Seismic Retrofit of Structures with Supplemental Damping: Part I-Fluid Viscous Damping Devices," Report No. NCEER-95-0001, National Center for Earthquake Engineering Research, State University of New York at Buffalo.
Reinhorn, A. M., and Valles, R. E. (1996), "Damage Evaluation in Inelastic Response of Structures: A Deterministic Approach," Report No. NCEER-96-xxxx, National Center for Earthquake Engineering Research, State University of New York at Buffalo.
Reinhorn, A.M., Madan, A., Valles, R.E. Reichmann, Y. and Mander, J.B. (1995). "Modeling of Masonry Infill Panels for Structural Analysis", Technical Report NCEER-95-0018, State University of New York at Buffalo.
.Sivaselvan, M. V. (1999). "Hysteretic degrading models for nonlinear structural analysis", Master's thesis, University at Buffalo
Valles, R. E., Reinhorn, A.M., and Barrón, R. (1996), "Seismic Evaluation of a Low-Rise RC Building in the Vicinity of the New Madrid Seismic Zone," Technical Report NCEER-96-xxxx, National Center for Earthquake Engineering Research, State University of New York at Buffalo (in press).
Valles, R. E., Reinhorn, A.M., S. K. Kunnath, C. Li and A. Madan, (1996b), "IDARC 2D 2D Version 4.0: A Program for the Inelastic Damage Analysis of Buildings.," Technical Report NCEER-96-0010, National Center for Earthquake Engineering Research, State University of New York at Buffalo..

(N)MCEER REPORTS

Programs

1. PARK, Y.J., REINHORN, A., KUNNATH, S.K., "IDARC ‑ Inelastic Damage Analysis of Reinforced Concrete Wall Frame Structures", Report NCEER‑87‑0008, (PB88‑134325/AS), NCEER/SUNY/Buffalo, 1987.^*

2. KUNNATH,S.K., REINHORN, A.M., and LOBO, R.F., "IDARC Version 3.0: Inelastic Damage Analysis of Reinforced Concrete Structures," Technical Report NCEER‑92‑0022, National Center for Earthquake Engineering Research, SUNY/Buffalo, 1992.

3. VALLES R.E., REINHORN A.M., KUNNATH S.K., LI C., AND MADAN A., “IDARC2D Version 4.0 - A computer Program for the Inelastic Drainage Analysis of Buildings,”, NCEER Technical Report NCEER‑96-0010, National Center for Earthquake Engineering Research, SUNY/Buffalo,1996.

4. REINHORN A. M., ROH H., SIVASELVAN M., KUNNATH S. K., VALLES R. E., MADAN A., LI C., LOBO R., PARK Y. J. (2009), “IDARC 2D Version 7.0: A Program for the Inelastic Damage Analysis of Structures”, MCEER Technical Report- MCEER-09-0006, University at Buffalo – the State University of New York

Models and Verification Studies

1. REINHORN, A.M., SEIDEL, M.I., KUNNATH, S.K. and PARK, Y.J., "Damage Assessment of Reinforced Concrete Structures in Eastern United States", Report NCEER‑88‑0016, NCEER/SUNY/Buffalo, 1988.^*

2. REINHORN, A.M., KUNNATH, S.K. and PANAHSHAHI, N., "Modeling R/C Building Structures with Flexible Floor Diaphragms (IDARC2)", Report NCEER‑88‑0035, NCEER/SUNY/Buffalo, 1988.^*

3. KUNNATH, S.K. and REINHORN, A.M., "Inelastic Analysis of Three‑Dimensional R/C Building Structures (IDARC‑3D) ‑ Part I ‑ Modeling", Report NCEER‑89‑0011, NCEER/SUNY/Buffalo, 1989^*.

4. BRACCI, J.M., REINHORN, A.M. MANDER.,J.B., "Seismic Resistance of Reinforced Concrete Frame Structures Designed Only for Gravity Loads: Part I ‑ Design and Properties of a One‑Third Scale Model Structure," Technical Report NCEER‑92‑0027, National Center for Earthquake Engineering Research, SUNY/Buffalo, 1992.^*

5. BRACCI, J.M., REINHORN, A.M., MANDER,J.B., "Seismic Resistance of Reinforced Concrete Frame Structures Designed Only for Gravity Loads: Part III ‑ Experimental Performance and Analytical Study of Structural Model," Technical Report NCEER‑92‑0029, National Center for Earthquake Engineering Research, SUNY/Buffalo, 1992.^*

6. BRACCI, J.M., REINHORN, A.M., MANDER,J.B., "Evaluation of Seismic Retrofit of Reinforced Concrete Frame Structures: Part II ‑ Experimental Performance and Analytical Study of Retrofitted Structural Model," Technical Report NCEER‑92‑0031, National Center for Earthquake Engineering Research, SUNY/Buffalo, 1992.^*

7. LOBO, R.F., BRACCI, J.M., SHEN, K.L., REINHORN, A.M., and SOONG, T.T., "Inelastic Response of R/C Structures with Viscoelastic Braces," Technical Report NCEER‑93‑0006, National Center for Earthquake Engineering Research, SUNY/Buffalo, 1993.^*

8. REINHORN, A.M., LI C., and Constantinou, M.C. “Experimental and Analytical Investigation of Seismic Retrofit of Structures with Supplemental Damping, Part I Fluid Viscous Damping devices” , Technical Report NCEER-95-0001, National Center for Earthquake Engineering Research, SUNY/Buffalo,1995.

9. Li. C. and REINHORN, A.M. “Experimental and Analytical Investigation of Seismic Retrofit of Structures with Supplemental Damping, Part II Friction Damping Devices,” Technical Report NCEER-95-0009, National Center for Earthquake Engineering Research, SUNY/Buffalo.

10. REINHORN, A.M., and LI C., “Experimental and Analytical Investigation of Seismic Retrofit of Structures with Supplemental Damping, Part III Viscous Walls,” Technical Report NCEER-95-0013, National Center for Earthquake Engineering Research, SUNY/Buffalo,1995.

11. REINHORN, A.M., MADAN, A. AND MANDER, J.B., “Analysis of Infill Masonry Walls”, Technical Report NCEER‑95-0018, National Center for Earthquake Engineering Research, SUNY/Buffalo, 1995

12. REINHORN, A.M. MADAN, A., VALLES, R.E., REICHMANN, Y., and MANDER, J.B., “Modeling of Masonry Infill Panels for Structural Analysis, NCEER-95-0018, NCEER/SUNY/Buffalo 1995.

13. REINHORN, A.M. and SIVASELVAN, M. “Hysteretic Models For Cyclic Behavior of Deteriorating Inelastic Structures”, Report MCEER-99-0018, MCEER/SUNY/Buffalo 1999.

PAPERS IN ARCHIVAL JOURNALS AND BOOKS CHAPTERS

1. KUNNATH, S.K. and REINHORN, A.M., "Seismic Evaluation of R/C Frame Wall Buildings", ACI/Concrete International, Design & Construction, Special Issue, Vol. 11, No. 8, pp. 57‑61, August 1989.

2. SEIDEL, M.I., REINHORN, A.M., and PARK, Y.J., "Seismic Damageability Assessment of R/C Buildings in Eastern U.S.", ASCE/Journal of Structural Engineering, Vol.115, No.9, pp. 2184‑2203, Sept. 1989.

3. KUNNATH, S.K., REINHORN, A.M. and PARK, Y.J., "Analytical Modeling of Inelastic Seismic Response of R/C Structures", ASCE/Journal of Structural Engineering, Vol. 116, No. 4, 996‑1017, April, 1990.

4. KUNNATH, S.K., PANAHSHAHI, N., and REINHORN, A.M., "Seismic Response of RC Buildings With Inelastic Floor Diaphragms", Journal of Structural Engineering, Vol. 117, No. 4 pp. 1218‑1237, 1991.

5. KUNNATH, S.K., REINHORN, A.M. and ABEL, J.F., "A Computational Tool for Evaluation of Seismic Performance of R/C Buildings," Computers and Structures. Vol. 41, No. 1, pp. 157‑171, 1991.

6. LOBO,R.F., BRACCI, J.M., SHEN, K., REINHORN, A.M., and SOONG, T.T., "Inelastic Response of R/C Structures with Viscoelastic Braces", Earthquake Spectra, Vol. 9, No. 3, August 1993, pp. 419‑446.

7. KUNNATH, S.K. and REINHORN, A.M., "Efficient Modeling Scheme for Transient Analysis of Inelastic RC Structures," Microcomputers in Civil Engineering, International Journal of Computer‑Aided Civil and Infrastructure Engineering, Vol. 10, pp. 97-110, December 1994.

8. KUNNATH, S.K., HOFFMANN, G., REINHORN, A.M., and MANDER, J.B., "Gravity Load Designed Reinforced Concrete Buildings Part I: Seismic Evaluation of Existing Construction," ACI/Structural Journal, Vol. 92, No. 3, pp.343-354, May 1995.

9. KUNNATH, S.K., REINHORN, A.M., HOFFMANN, G., and MANDER, J.B., "Gravity Load Designed Reinforced Concrete Buildings Part II: Evaluation of Detailing Enhancements," ACI/Structural Journal, Vol.92, No.4, pp. 470-478, July-Aug., 1995.

10. BRACCI, J.M., REINHORN, A.M., and MANDER, J.B., "Seismic Resistance of Reinforced Concrete Frame Structures Designed For Gravity Loads: Performance of Structural System," ACI/Structural Journal, Vol.92, No.5,pp. 597-609, Sept-Oct. 1995.

11. BRACCI, J.M., REINHORN, A.M., and MANDER, J.B., "Seismic Retrofit of Reinforced Concrete Buildings Designed for Gravity Loads: Performance of Structural Model," ACI/Structural Journal, Vol.92, No.6, pp. 601-613, Nov-Dec., 1995.

12. NAEIM F., DIJULIO R.M. JR., BENUSKA K.V. , REINHORN A.M. AND LI C. “Seismic Performance Analysis of a Multistory Steel Moment Frame Building Damaged During the 1994 Northridge Earthquake”, Journal of the Structural Design of Tall Buildings, V.4, pp. 263-312., Dec.1995 (Best Paper Award).

13. MADAN, A., REINHORN, A.M., MANDER, J., and VALLES, R., “Modeling of Masonry Infill Panels For Structural Analysis,” ASCE/Journal of Structural Engineering, Vol. 123, No. 10, , pp. 1295-1302., Oct. 1997

14. REINHORN, A.M., KUNNATH, S.K., BRACCI, J. and MANDER, J., "Normalized Damage Index for Evaluation of Buildings", in Seismic Engineering: Research and Practice, C.A. Kircher and A.K. Chopra (Eds.), ASCE, New York, pp. 507‑516, 1989.

15. REINHORN, A.M., MANDER, J.B., BRACCI, J., and KUNNATH, S.K., "Simulation of Seismic Damage of RC Buildings in Eastern U.S.," Structural Safety & Reliability (ICOSSAR), A.H.S. Ang, M. Shinozuka and G.I. Schuller (Eds.), Vol.1, pp.407‑414, ASCE, New York, 1990.

16. REINHORN, A.M., and Li, C., “Retrofit of Structures Using Damping Devices,” in Restructuring: America and Beyond [Masauel Sanayei (editor)], ASCE, NY, Vol. 1, pp. 760-763, 1995.

17. REINHORN, A.M., “Inelastic Analysis Techniques in Seismic Evaluations", in Seismic Design Methodologies for the Next Generation of Codes (Krawinkler and Fajfar, eds), from Workshop, Bled Solvenia, June 24-27, 1997 (Balkema Publishers).pp. 277-287

18. SIVASELVAN M., and REINHORN, A.M., “Hysteretic Models for Deteriorating Inelastic”, ASCE/Journal of Engineering Mechanics, Vol. 126, No. 6, Jun. 2000, pp. 633-640.

19. ROH, H. and REINHORN, A. M. (2009), “Nonlinear Static Analysis of Structures with Rocking Columns”, ASCE, Journal of Structural Engineering, accepted and in press.

20. ROH, H, and REINHORN, AM. (2008), “Dynamic response of weakened structures using rocking columns”, Proceedings of 14WCEE, Beijing, China Paper # 05-01-0021.

21. ROH, H. (2007), “Seismic behavior of structures using rocking columns and viscous dampers. Ph.D. Dissertation, University at Buffalo-the State University of New York.