Assessment of improved nonlinear static procedures in FEMA-440

Akkar, Dede Sinan
Metin, Ash
Nonlinear static procedures (NSPs) presented in the FEMA-440 document are evaluated for nondegrading three- to nine-story reinforced concrete moment-resisting frame systems. Evaluations are based on peak single-degree-of-freedom displacement, peak roof, and interstory drifts estimations. A total of 78 soil site records and 24 buildings with fundamental periods varying between 0.3 s-1.3 s are used in 2,832 linear and nonlinear response-history analyses to derive the descriptive statistics. The moment magnitude of the ground motions varies between 5.7 and 7.6. All records are within 23 km of the causative fault representing near-fault ground motions with and without pulse signals. The statistics presented suggest that lateral loading patterns used in pushover analysis to idealize the building systems play a role in the accuracy of NSPs investigated. Both procedures yield fairly good deformation demand estimations on the median. Displacement coefficient method (DCM) tends to overestimate the global deformation demands with respect to the capacity spectrum method (CSM). The conservative deformation demand estimations of DCM are correlated with the normalized lateral strength ratio, R. The CSM tends to overestimate the deformation demands for the increasing displacement ductility, mu.


ELMEZAINI, N; CITIPITIOGLU, E (American Society of Civil Engineers (ASCE), 1991-10-01)
A practical and powerful technique for the discrete representation of reinforcement in finite element analysis of prestressed and reinforced concrete structures is presented. Isoparametric quadratic and cubic finite elements with movable nodes are developed utilizing a correction technique for mapping distortion. Reinforcing bars and/or prestressing tendons are modeled independently of the concrete mesh. Perfect or no bond as well as any bond-slip model can easily be represented. The procedure is succes...
Analysis of the flexural strength of prestressed concrete flanged sections
Baran, Eray; French, Catherine (Precast/Prestressed Concrete Institute, 2005-01-01)
Inconsistencies in the sectional response of prestressed concrete flanged sections predicted by the AASHTO LRFD and AASHTO Standard Specifications, including the maximum reinforcement limits, may arise due to different interpretations of the equivalent rectangular compressive stress block idealization. Strain compatibility analyses with nonlinear material properties were performed for a variety of non-rectangular prestressed concrete sections to identify the inconsistencies between the two specifications. R...
Discussion of "Design of steel frames using ant colony optimization" by Charles V. Camp, Barron J. Bichon and Scott P. Stovall
Saka, MP (American Society of Civil Engineers (ASCE), 2006-07-01)
A design procedure utilizing an ant colony optimization (ACO) technique is developed for discrete optimization of steel frames. The objective function considered is the total weight (or cost) of the structure subjected to serviceability and strength requirements as specified by the American Institute for Steel Construction (AISC) Load and Resistance Factor Design, 2001. The design of steel frames is mapped into a modified traveling salesman problem (TSP) where the configuration of the TSP network reflects t...
Test method for determining the shear modulus of elastomeric bearings
Topkaya, Cem (American Society of Civil Engineers (ASCE), 2002-06-01)
The shear modulus of the elastomer is the most important material property related to the behavior of elastomeric bearings used principally at supports in bridges. Current methods for determining the shear modulus usually require small test samples cut from manufactured bearings. Such tests are costly, do not necessarily represent the performance of the full-size bearing, and are destructive. A new shear test method, called the inclined compression test, is reported that is nondestructive and only requires ...
Performance Examination of Two Seismic Strengthening Procedures by Pseudodynamic Testing
Kurt, Efe Gokce; Kurç, Özgür; Binici, Barış; Canbay, Erdem; Ozcebe, Guney (American Society of Civil Engineers (ASCE), 2012-01-01)
Pseudodynamic testing was employed to observe the seismic performance of two retrofit methods on two-story, three-bay frame structures. The test frames had hollow clay tile (HCT) infill in the central bay and incorporated the seismic deficiencies of Turkish construction practice, such as use of plain reinforcing bars, low-strength concrete, and insufficient confining steel. Two noninvasive and occupant-friendly retrofit schemes suggested in the Turkish Earthquake Code, namely, use of fiber-reinforced polyme...
Citation Formats
D. S. Akkar and A. Metin, “Assessment of improved nonlinear static procedures in FEMA-440,” JOURNAL OF STRUCTURAL ENGINEERING-ASCE, pp. 1237–1246, 2007, Accessed: 00, 2020. [Online]. Available: