Energy-based seismic performance of reinforced concrete frame structures

Abstract

The distribution of structural hysteretic energy is significant in energy-based seismic performance evaluations of reinforced concrete (RC) structures. This research involved the design of a six-storey RC frame and analysis of its dynamic time history for typical ground motions. Based on a comparison of the numerical results of the earthquake input energy and structural hysteretic energy under minor, moderate and major levels of earthquakes of grades 8 and 9, the allocation and distribution of structural hysteretic energy were studied. The results indicate that the ground motion characteristics have a small influence on the ratio of the maximum hysteretic energy to the maximum earthquake input energy, as well as on the distribution pattern of hysteretic energy along the height of the structure. Upper storeys dissipate less energy than lower ones and are little affected by ground motion severity when the plasticity of the structure is sufficiently developed. Beams dissipate most hysteretic energy in the structures, and energy consumption of the columns is almost zero except in the lower columns. Thus, larger plastic deformation is found to be concentrated in the lower storeys, with damage to the structure in the form of a strong column and weak beam.

Evaluation of Damage Indices for Rectangular Concrete-filled Steel Tube Structures

“…The indicator , however, may underestimate the real damage extent of structures subjected to earthquakes since the structural ultimate state was not considered. Consequently, some authors modified the form of initial stiffness over reduced secant stiffness ratio and suggested a new damage index as given below [12] 0 0 ,…”

“…In this regard, a building would survive an earthquake with the energy dissipation capacity above the earthquake input energy. Therefore, the energy dissipation capacity can be utilized as a key indicator to measure damage in structures [13]. As shown in Fig.1., an energy coefficient is employed as a damage index expressed as:…”

“…Based on the comparison of stiffness of a building before and after an earthquake, Ghobarah et al [6] proposed a new rational damage indicator by means of two pushover analysis. Another recent stiffness related damage parameter was suggested by Guan et al [12], in which initial stiffness, the secant stiffness at the performance point for a designed earthquake intensity, and stiffness at failure were considered. Obviously, compared with the deformation-based parameters, there is an improvement due to the consideration of the stiffness deterioration of structures under cyclic loading.…”

“…The essence of seismic damage of structures is the procedure of earthquake input energy transfer, conversion, and dissipation [13]. In this respect, energy-based parameters appear to be preferable damage indicators, particularly for ideal ductile systems, in which the failure is principally caused by repeated inelastic deformations [6], [14].…”

Study on Stability of Tall Buildings Under Earthquake

“…Structures in earthquake damage effect depend on the dynamic characteristics of earthquake and dynamic characteristics of structure. Seismic dynamic characteristic can be determined by seismic amplitude of vibration, frequency and duration to describe; structural dynamic characteristics including natural period of vibration, vibration and damping [7]. China's seismic design [8] specification: Special irregular building, a building and the specific conditions of the high-rise buildings should adopt the time-history analysis method for calculating.…”