Calculation Technique for Stress-Strain Analysis of Rc Elements Subjected to High-Cycle Compression / Daugiacikle Gniuždymo Apkrova Veikiamų Gelžbetoninių Elementų Įtempių Ir Deformacijų Skaičiavimo Metodika

Abstract

Theoretical models for the evaluation of fatigue on reinforced concrete structures most commonly fall into two major groups. The first and more widely used group of models is based on S-N curves and the static stress state. These models provide the final load cycle count until structural failure but do not consider redistribution of stresses within the structure or strain evolution over time. The second group accounts for deterioration of concrete over time. However, due to difficulties in application and high computational costs, these models are not fully evolved. A new simplified iterative method for reinforced concrete columns based on previous research by Zanuy et al. (2009) is presented in this paper. This model allows for estimation of stress redistribution and progressive degradation of concrete under high-cycle loading.

Residual strength of concrete subjected to fatigue based on machine learning technique

“…This strain evolution of concrete under compressive fatigue can be usually divided into three stages. 15,[62][63][64] In the first stage, within 10% of the total number of cycles (i.e., n=N=0.1), the concrete nonlinearly deforms at a decreasing rate. In the second stage, the strain rate shows almost constant trend, which usually account for about 60% of the fatigue life.…”

“…[5][6][7][8][9][10][11][12] For this reason, previous fatigue research focused on characterizing the strength degradation of concrete and steel materials under fatigue depending on various stress level and loading frequency. [13][14][15][16][17][18] These existing studies reveal that there are inter-related mechanisms among key variables including the compressive strength, aspect ratio of test specimen, maximum stress level, minimum stress to maximum stress ratio, and fatigue loading frequency. In addition, it is very hard to justify how much service life (or residual strength) remains after fatigue damage even though extensive fatigue test results are available.…”

“…The internal resistance mechanism in an RC member basically originates from two components: compressive resistance provided by concrete and its counterpart provided by reinforcements in tension 5–12 . For this reason, previous fatigue research focused on characterizing the strength degradation of concrete and steel materials under fatigue depending on various stress level and loading frequency 13–18 . These existing studies reveal that there are inter‐related mechanisms among key variables including the compressive strength, aspect ratio of test specimen, maximum stress level, minimum stress to maximum stress ratio, and fatigue loading frequency.…”