L. Solazzi^1,2, C. Petrogalli¹, M. Lancini¹

Structural Durability & Health Monitoring, Vol.8, No.4, pp. 329-340, 2012, DOI:10.32604/sdhm.2012.008.329

Abstract A study on vibrations related to rolling contact fatigue test bench and a possible way to correlate this mechanical behavior and damage of the specimens is presented. In particular it has been evaluated the possibility to detect and quantify, thanks to vibration analysis, the damage on two discs subjected to rolling contact fatigue in different working conditions. Paper is divided in two parts. In the first part there is a description of test bench and results of its static and modal analyses. Then, some tests were carried out changing working conditions and specimens' parameters and More >

F. Curà¹, A. Gallinatti¹, R. Sesana¹

Structural Durability & Health Monitoring, Vol.8, No.1, pp. 45-60, 2012, DOI:10.3970/sdhm.2012.008.045

Abstract In this paper the effect of high cycle fatigue damaging on a commercial steel is investigated by means of experimental measurement of mechanical and dissipative parameters variation during fatigue testing. Experimental procedures for HCF damage incrementing on specimens and for parameter measurement have been defined. A statistical analysis of the significance of the results have been applied to select the parameters which best represent the damage progression on the specimen. More >

F. Cianetti¹

Structural Durability & Health Monitoring, Vol.8, No.1, pp. 1-30, 2012, DOI:10.3970/sdhm.2012.008.001

Abstract This research activity refers to the problem of fatigue damage evaluation of mechanical components subjected to random loads. In detail, the present paper describes a procedure, developed by the author, that, starting from component modal modelling, can very quickly gives an answer to the request not only of a qualitative evaluation of its stress state but also of a quantitative and very reliable estimation of the component damage. This estimation is available (both in time and in frequency domain), regardless of the stress state recovery, only by an appropriate elaboration of lagrangian coordinates and elements stress 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 >

S.Mohanty¹, A. Chattopadhyay², J. Wei³, P. Peralta⁴

Structural Durability & Health Monitoring, Vol.5, No.3, pp. 227-250, 2009, DOI:10.3970/sdhm.2009.005.227

Abstract This paper proposes unsupervised system identification based methods to estimate time-series fatigue damage states in real-time. Ultrasound broadband input is used for active damage interrogation. Novel damage index estimation techniques based on dual sensor signals are proposed. The dual sensor configuration is used to remove electrical noise, as well as to improve spatial resolution in damage state estimation. The scalar damage index at any particular damage condition is evaluated using nonparametric system identification techniques, which includes an empirical transfer function estimation approach and a correlation analysis approach. In addition, the effectiveness of two sensor configurations More >

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,… 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 >