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Crack growth diagnostic of ball bearing using vibration analysis

Belaidi S., Lecheb S., Chellil A., Mechakra H., Safi B., Kebir H.

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 1

35--45

EN

It is known that supported ball bearings have great effects on the vibrations of the gear transmission system, above in all the presence of local faults as well as the crack growths. For this purpose, this paper focuses on shock and vibration crack growth diagnostic of ball bearing using vibration analysis. Our work is devoted first to a study the static behaviour of the ball bearing by determining the stress, strain and displacement, then its dynamic behaviour by determining the first four natural frequencies. Secondly, a dynamic analysis study of the bearing was carried with defects as a function of crack size and location. The obtained results clearly show that the natural frequencies decrease in a non-linear way with the growth of the length of the crack, on the other hand the stress increases with the presence of the singular points of the crack. Finally, this residual decrease in natural frequencies can be used as an indicator of the state of failure, as well as a parameter used for the diagnosis and screening, and to highlight the fatigue life of the bearing.

2

Structure Activity Relationships, QSAR Modeling and Drug-like calculations of TP inhibition of 1,3,4-oxadiazoline-2-thione Derivatives

Almi Z., Belaidi S., Lanez T., Tchouar N.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 18

113--124

EN

QSAR studies have been performed on twenty-one molecules of 1,3,4-oxadiazoline-2-thiones. The compounds used are among the most thymidine phosphorylase (TP) inhibitors. A multiple linear regression (MLR) procedure was used to design the relationships between molecular descriptor and TP inhibition of the 1,3,4-oxadiazoline-2-thione derivatives. The predictivity of the model was estimated by cross-validation with the leave-one-out method. Our results suggest a QSAR model based of the following descriptors: logP, HE, Pol, MR, MV, and MW, qO1, SAG, for the TP inhibitory activity. To confirm the predictive power of the models, an external set of molecules was used. High correlation between experimental and predicted activity values was observed, indicating the validation and the good quality of the derived QSAR models.

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Conformational Analysis, Substituent Effect and Structure activity Relationships of 16-Membered Macrodiolides

Mazri R., Belaidi S., Kerassa A., Lanez T.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 14, iss. 2

146-167

EN

Electronic structures, Conformational Analysis, effect of the substitution and structure activity Relationships for macrodiolides, have been studied by PM3 and ab initio methods. In the present work, the calculated values, namely net charges, bond lengths, MESP, dipole moments, electron-affinities, heats of formation, drug-likeness and QSAR properties, are reported and discussed in terms of the biological activity of macrodiolides.