Long-Term Cyclic Loading Impact on the Creep Deformation Mechanism in Cohesive Materials

Abstract

Long-term cyclic loading is observed in a wide range of human activities, as well as in nature, such as in the case of ocean waves. Cyclic loading can lead to ratcheting which is defined as progressive accumulation of plastic deformation in a material. Long-term cyclic loading causes a time effect (creep), which is a secondary compression effect. In this article, we conducted 15 triaxial tests on four types of cohesive materials in undrained conditions to evaluate the damage and failure mechanism. To characterize the strain and pore pressure development, we modified the Yanbu resistance concept. On the basis of the static creep tests, we concluded that the stress paths for undrained creep behavior have to take into account the pore pressure developed during long-term cyclic loading. Pore pressure build-up and plastic strain accumulation during long-term cyclic loading are dependent on the number of loading cycles. Finally, we proposed the failure criterion, which was based on the Modified Cam-Clay constitutive model.

Evaluation of Factors Affecting the Performance of Fiber-Reinforced Subgrade Soil Characteristics Under Cyclic Loading

“…Previous studies by Głuchowski & Sas [40] and An et al [41] have suggested that soil stiffness is high at low cyclic stress levels but decays with an increase in high cyclic stress levels. In addition, their studies supported the fact that strain level increases with cyclic stress, hence resilient modulus decreases with an increase in cyclic stress.…”

Plastic Shakedown Behavior and deformation Mechanisms of Ti17 Alloy under Long Term Creep-Fatigue Loading

“…The ratchet strain rate decreases rapidly and reduces to nearly 0% in the 3rd cycle, after which the ratchet strain caused by stress cycling no longer increases. The lowest point of decreasing ratchet strain rate is also in the 3rd cycle, i.e., the plastic shakedown transition point, which indicates that the phenomenon of anelastic recovery not only slows down the accumulated creep strain rate, but also reduces the ratchet strain rate [28]. Because anelastic recovery can reduce the accumulation of creep damage in the material [29], which is one of the most important reasons for the specimen to exhibit plastic shakedown.…”

Plastic Shakedown Behavior and Deformation Mechanisms of Ti17 Alloy under Long Term Creep–Fatigue Loading

“…The ratchet strain rate decreases rapidly and reduces to nearly 0% in the 3rd cycle, after which the ratchet strain caused by stress cycling no longer increases. The lowest point of decreasing ratchet strain rate is also in the 3rd cycle, i.e., the plastic shakedown transition point, which indicates that the phenomenon of anelastic recovery not only slows down the accumulated creep strain rate, but also reduces the ratchet strain rate [29]. Because anelastic recovery can reduce the accumulation of creep damage in the material [30], this is one of the most important reasons for the specimen to exhibit plastic shakedown.…”