Cyclic Plasticity Based Low-Cycle Fatigue Models for Metal Structure

This paper presents two phenomenological models to describe the low cycle fatigue behavior of large- scale infrastructures which are made up of non linear kinematic hardening materials. The first model basically consists of a new non linear hardening model which is suggested by making further extension to previous Armstong Fedrick model. The second model also consists of a new hardening model with incremental plasticity algorithms by providing a simple alternative to the available two surface plasticity theory. Fatigue fracture would initiate when the internal history variable reaches the threshold value and is deemed as the major concept behind the low cycle fatigue assessment. Elastoplastic behaviour of proposed models are compared with both previous models and the real material behaviour. Finally the applicability of proposed models in the vicinity of civil engineering problems is confirmed by discussing a case study.