D. Benasciutti¹, R. Tovo¹

Structural Durability & Health Monitoring, Vol.2, No.3, pp. 149-164, 2006, DOI:10.3970/sdhm.2006.002.149

Abstract The probability density functions used to characterize the distribution of fatigue cycles in random loads are usually defined over an infinite domain. This means that they give a non-zero probability to count cycles with an infinitely large peak or valley, which however seems of less physical sense. Moreover, practically all the methods existing in the literature completely neglect the negative effect on fatigue strength produced by fatigue cycles with positive mean values. With theses premises, this work tries to further extending the probabilistic theory used by the frequency-domain methods by addressing to distinct problems. First, it tries to include in… More >

Ying Zhao¹, Mohammad Noori^1,2, Wael A. Altabey^1,3,*, Ramin Ghiasi⁴, Zhishen Wu¹

Structural Durability & Health Monitoring, Vol.13, No.1, pp. 85-103, 2019, DOI:10.32604/sdhm.2019.04695

Abstract This paper introduces a stiffness reduction based model developed by the authors to characterize accumulative fatigue damage in unidirectional plies and (0/θ/0) composite laminates in fiber reinforced polymer (FRP) composite laminates. The proposed damage detection model is developed based on a damage evolution mechanism, including crack initiation and crack damage progress in matrix, matrix-fiber interface and fibers. Research result demonstrates that the corresponding stiffness of unidirectional composite laminates is reduced as the number of loading cycles progresses. First, three common models in literatures are presented and compared. Tensile viscosity, Young’s modulus and ultimate tensile stress of composites are incorporated as… More >

V. Tvergaard¹, T. Ørts Pedersen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.2, pp. 89-94, 2000, DOI:10.3970/cmes.2000.001.249

Abstract The development of fatigue damage in a tool-steel metal matrix discontinuously reinforced with TiC particulates is analysed using a numerical cell model. The material is subjected to cyclic loading, and the matrix material is represented by a cyclic plasticity model, which uses a superposition of kinematic and isotropic hardening, with continuum damage mechanics incorporated to model fatigue damage evolution. The cell model represents a material with transversely staggered particulates. With focus on low cycle fatigue, the effect of balanced as well as unbalanced cyclic loading is studied. More >

F. Casciati¹, S. Casciati², L. Faravelli¹, A. Marzi¹

CMC-Computers, Materials & Continua, Vol.23, No.3, pp. 287-306, 2011, DOI:10.3970/cmc.2011.023.287

Abstract The potential offered by the main features of shape memory alloys (SMA) in Structural Engineering applications is object of attention since two decades. The main issues concern the predictability of the material behavior and the fatigue lifetime of macro structural elements (as different from wire segments). In this paper, the fatigue characteristics, at given temperatures, of multigrain samples of a specific Cu-based alloy are investigated. The results of laboratory tests on bar specimens are discussed. The target is to model the manner in which the effects of several loading-unloading cycles of different amplitude cumulate. More >