Author
Egor P. Popov
Other affiliations: Skidmore, Owings & Merrill
Bio: Egor P. Popov is an academic researcher from University of California, Berkeley. The author has contributed to research in topics: Finite element method & Beam (structure). The author has an hindex of 39, co-authored 102 publications receiving 5869 citations. Previous affiliations of Egor P. Popov include Skidmore, Owings & Merrill.
Papers published on a yearly basis
Papers
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TL;DR: In this article, the authors introduced the concept of a bounding surface in the stress space which always encloses the loading surface, and a parameter defined by the relative position of the loading and the bounding surfaces, and the plastic work done during the most recent loading, determine the value of the plastic modulus.
Abstract: A number of observations are made on the macroscopic behavior of materials subjected to uniaxial random cyclic loadings. These observations are then generalized to construct a model describing the material behavior for complex multiaxial loadings, in particular for cyclic loadings. This generalization introduces the concept of a bounding surface in the stress space which always encloses the loading surface. A parameter defined by the relative position of the loading and the bounding surface, and the plastic work done during the most recent loading, determine the value of the plastic modulus.
827 citations
DOI•
01 Jan 1982
TL;DR: In this article, the local bond stress-slip relationships of deformed bars embedded in confined concrete under monotonic and cyclic loading for various bond conditions were investigated in an extensive experimental study.
Abstract: The local bond stress-slip relationships of deformed bars embedded in confined concrete under monotonic and cyclic loading for various bond conditions were investigated in an extensive experimental study. The results were used to deduce an analytical model of the bond behavior under random excitations. By evaluating experimental results of long anchorages, the model was extended to cover the bond conditions found in joints of R/C frames under severe seismic excitations. The model was successfully used to predict the behavior of deformed bars anchored at interior joints and subjected to various loading histories.
755 citations
627 citations
TL;DR: Slotted Bolted Connections (SBCs) as discussed by the authors are modified bolted connections designed to dissipate energy through friction during rectilinear tension and compression loading cycles, and they have been shown to be more uniform and simpler to model analytically than that with steel on steel surfaces.
Abstract: Slotted Bolted Connections (SBCs) are modified bolted connections designed to dissipate energy through friction during rectilinear tension and compression loading cycles. Experimental results on two types of SBCs are reported. In one type, friction occurs between clean mill scale steel surfaces; in the other, friction is between clean mill scale steel and brass surfaces. The behavior of connections with brass on steel frictional surfaces is found to be more uniform and simpler to model analytically than that with steel on steel surfaces. These connections maintain essentially constant slip force, and unlike those with steel on steel surfaces, require minimal overstrength of the system in design. The frictional mechanisms giving rise to the observed behavior are explained. As an example of application a one story diagonally braced frame was designed and its behavior determined for four different earthquakes. Experimental results are presented for the fabricated SBC for this frame subjected consecu...
231 citations
TL;DR: In this article, a structural steel system that employs diagonal bracing with large eccentricity between the brace-beam connection and the beam column joint is described, which provides a ductile fuse that yields in shear and prevents brace buckling.
Abstract: A unique, practical structural steel system that possesses many advantages in the seismic design of structures is described The system employs diagonal bracing with large eccentricity between the brace-beam connection and the beam column joint The eccentricity provides a ductile fuse that yields in shear and prevents brace buckling Static and dynamic analyses indicates that this system can perform well during earthquakes, because it combines the stiffness of a braced frame with the excellent energy dissipation of a moment-resisting frame One-third-scale experiments showed that the system behaves as predicted in the analyses It dissipates large amounts of energy while maintaining a very stiff structure, and it offers many potential applications in the seismic design of structures
190 citations
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TL;DR: In this paper, the authors provide a concise point of departure for researchers and practitioners alike wishing to assess the current state of the art in the control and monitoring of civil engineering structures, and provide a link between structural control and other fields of control theory.
Abstract: This tutorial/survey paper: (1) provides a concise point of departure for researchers and practitioners alike wishing to assess the current state of the art in the control and monitoring of civil engineering structures; and (2) provides a link between structural control and other fields of control theory, pointing out both differences and similarities, and points out where future research and application efforts are likely to prove fruitful. The paper consists of the following sections: section 1 is an introduction; section 2 deals with passive energy dissipation; section 3 deals with active control; section 4 deals with hybrid and semiactive control systems; section 5 discusses sensors for structural control; section 6 deals with smart material systems; section 7 deals with health monitoring and damage detection; and section 8 deals with research needs. An extensive list of references is provided in the references section.
1,883 citations
TL;DR: In this paper, the cyclic constitutive equations developed and used at ONERA and LMT-Cachan are presented in detail in terms of a hierarchy of various models, including the Ohno-Kachi time-independent plasticity theory, two unified viscoplastic models by Walker and by Krempl and Yao, the new developments of the endochronic theory by Watanabe and Atluri.
1,446 citations
TL;DR: In this paper, the main ingredients and assumptions of developing macroscopic inelastic constitutive equations, mainly for metals and low strain cyclic conditions, have been discussed, with some comparisons with the previous ones, including more recent developments that offer potential new capabilities.
1,414 citations
TL;DR: In this paper, three different approaches are considered for the description of kinematic behavior: (i) the use of independent multi-yield surfaces, (ii) models with two surfaces only, (iii) the so-called "nonlinear-kinematic hardening rule" defined by a differential equation.
1,377 citations
TL;DR: In this paper, the state-of-the-art structural control systems for wind and seismic response of buildings and bridges are discussed, as well as their advantages and limitations in the context of seismic design and retrofit.
1,026 citations