عملکرد لرزه ای و تغییر شکل قاب
Abstract
۱٫ Introduction
۲٫ Computational modeling
۳٫ Analytical results
۴٫ Conclusion
CRediT authorship contribution statement
Declaration of Competing Interest
Acknowledgement
References
Abstract
Engineered Cementitious Composites (ECC) is a typical High Performance Fiber Reinforced Cement-based Composite (HPFRCC), which possesses the characteristics of ultra-high tensile ductility and energy dissipation capacity. One of the potential applications of ECC is to replace conventional concrete in the seismic resistant structures. However, to date, the investigation on seismic performance of ECC at the structural level is still limited. This paper aims at evaluating the seismic performance of RECC frame on the basis of Performance-based Seismic Design (PBSD) concept and discussing the feasibility and practicability of applying ECC in structures for improving the seismic performance. The non-linear behavior of ECC material was simulated especially considering the strain hardening behavior in tension. By using the Incremental Dynamic Analysis (IDA) method, three types of frames, consisting of a normal RC frame, a RECC frame and an RECC/RC composite frame, were analyzed to evaluate the structural dynamic behavior of the frames. Comparative studies on the deformation limit states at five levels of seismic performance for these three different types of frames validated that RECC frames have superior deformation capacity comparing to traditional RC frames under high intensity earthquake. Comparison results also indicated that rationally applying ECC in key region of the structures can not only improve the seismic performance and deformation capacity of structures but also control the construction cost.
Introduction
Engineered Cementitious Composites (ECC), generally consists of cement, mineral admixture, fine aggregates, water, admixtures which are used to enhance the strength and workability, less than 2% volume of short fibers, was first developed by Li et al. [1–۳] based on the basic principle of micromechanics and fracture mechanics. Different from normal concrete with brittle tensile behavior and crack localization, ECC exhibits multiple fine cracks and strain-hardening behavior under tension. The opening of each crack is usually controlled to be less than 100 μm, and the ultimate tensile strain can reach over 3.0% [4–۶]. A typical tensile stress-strain relationship of ECC is shown in Fig. 1. The ultra-high tensile ductility and energy dissipation capacity of ECC just remedy the shortcomings of concrete and thus attract the attentions of many researchers and designers around the world. ECC is being considered for replacing conventional concrete in structures in high-intensity earthquake regions [7–۹]. Research efforts have focused on the seismic related behavior of ECC [10–۱۸], however, the researches with respect to ECC are mostly limited to the material level and component level, while the investigation focusing on ECC at structural level is still at the preliminary stage. Gencturk et al. [19–۲۰] established a constitutive model for ECC within Zeus-NL, and a two-story-two-span frame was simulated with the proposed model and tested under dynamic loading.