Damage and Crack Analysis for Reinforced Concrete Energy Dissipation Braced Frame (EDBF) under Low Cyclic Loads

Abstract:

Application of Miner criterion, cumulate damage variable was estimated based on pseudo-static experiment study for reinforced concrete energy dissipation braced frame (EDBF) under low cyclic loads, accordingly, the constitutive relations about damage was established; the linear hook law turned into non-linear stress-strain relations; the dissipated-energy factor c β was determined based on following factors: the cumulate damage variable, hysteretic energy determined by load-displacement curve, maximum deformation and yield force of EDBF; it supplied a quantitative basis of dissipated-energy for EDBF; There were two reasons in energy dissipation for EDBF: one was energy dissipation equipment acting, the other was concrete damaged and cracked or low cycle fatigue failure in this structure, and the latter part of energy was associated with amounts of cracks and crack size; then the forced mechanism of EDBF was analyzed, and the reason caused cracks and crack type of EDBF columns, beam and braces were explained based on forced mechanism: the columns, beam and braces of EDBF were compressed or tensed under low cyclic loads, so most of cracks of columns, beam and braces belonged to mode I cracks
This study supplied a method for estimating energy of EDBF under earthquake ground motion, and the results showed: columns in EDBF are easily damaged under earthquake ground motion, so the structural elements must be designed strong column, weak beam and weak brace.