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stiffness-degradation
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A new lateral load pattern for optimum design of concrete structures using the wave propagation theory
, Article Structures ; Volume 40 , 2022 , Pages 581-595 ; 23520124 (ISSN) ; Omidi, H ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
The current design procedure known as Force-Based Design (FBD) method, generally, does not lead to uniform distribution of drift, hysteretic energy, and ductility demands (or structural damage) along the height of the moment frames under strong earthquakes and these performance parameters can be much higher and concentrate damage on one or more of the lower structural stories. This paper presents an iterative wave propagation (WP) based technique to calculate the seismic nonlinear response of multistory buildings as an extension of the layered soil media, founded on bedrock and subjected to vertically propagating shear waves, which leads to the introduction of a new Lateral Load Pattern...
Estimation of Displacement Modification Factor for Soil Structure Systems with Embedded Foundation Structures and Stiffness Degradation Hysteresis Models
, M.Sc. Thesis Sharif University of Technology ; Ghannad, Mohammad Ali (Supervisor)
Abstract
The effect of soil structure interaction, on displacement modification factor in constant reduction factors (CR) is evaluated, studied for SDOF structures placed on flexible base modeled by 3DOF system as the base foundation (a sway, a rocking and an internal degree of freedom to see the frequency dependency of dynamic stiffness of soil). 60 records of FEMA-440 for 3 types of soils (B, C and D) are analyzed for 28 different soil-structure conditions, 6 different level of reduction factors, and varied secondary hardening for 2 different hysteresis behavior to see the effect of stiffness hardening. Results are plotted in spectrums to see the role of Tn.
Final results show that effect of...
Final results show that effect of...
New approach for fatigue life prediction of composite plates using micromechanical bridging model
, Article Journal of Composite Materials ; Volume 49, Issue 3 , February , 2015 , Pages 309-319 ; 00219983 (ISSN) ; Farsadi, M ; Koochi, A ; Khorashadizadeh, S. N ; Sharif University of Technology
SAGE Publications Ltd
2015
Abstract
The use of micromechanical models to study composite material's behavior leads to save time and cost. In this paper, bridging micromechanical models have been used in order to observe the behavior of unidirectional laminate composite under fatigue loading. In order to study the fatigue behavior, stiffness degradation has been studied as well as the strength degradation and a driftnet model has been proposed for each of them. The strength degradation has only been studied for the unidirectional fiber, while the stiffness degradation has been studied for the fibers with different fiber angle. The results are compared with macro-mechanical models and other methods in literature
Seismic performance of precast RC column to steel beam connections with variable joint configurations
, Article Engineering Structures ; Volume 160 , April , 2018 , Pages 408-418 ; 01410296 (ISSN) ; Bakhtiari Doost, R ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In the last decades, noticeable experimental and analytical investigations have been carried out on cast-in-place Reinforced Concrete column to Steel beam (RCS) connections, however rarely have been conducted on the precast RCS. In this paper, test results of four half-scale interior precast RCS connections with variable joint configurations are presented. The steel beams were connected to the precast column, using three specimens with extended face bearing plates and one with extended cover plates, embedded in the connection zone. The flanges of beams were strengthened with respect to scaled section, in order to increase the load transfer to the joint. All samples were loaded under reversed...