Condition and behaviour diagnostics of drive groups on belt conveyors Taško Maneski a,⇑ , Predrag Jovanc ˇic ´ b , Dragan Ignjatovic ´ b , Vesna Miloševic ´ -Mitic ´ a , Miloš Maneski c a University of Belgrade, Faculty of Mechanical Engineering, Kraljice Marije 16, 11120 Belgrade 35, Serbia b University of Belgrade, Faculty of Mining and Geology, Djušina 7, 11120 Belgrade 35, Serbia c University of Belgrade, Faculty of Architecture, Bulevar Kralja Aleksandra 73/II, 11000 Belgrade, Serbia article info Article history: Received 8 March 2011 Received in revised form 28 December 2011 Accepted 5 January 2012 Available online 11 January 2012 Keywords: Failure analysis Stress distribution Vibration Repairs Finite element analysis abstract Belt conveyors are complex systems with drive groups as functionally very important components. Their proper and reliable operational life is directly related to durability of the load-bearing steel structures. Drive units often have problems linked to increasing of vibrations of steel structures. Drive units on 2nd BWE-BC-S system on Drmno open cast mine (Serbia) and on waste dump on Pljevlja open cast mine (Montenegro) were used as the examples of behaviour and condition diagnostics. As the most suitable diagnostic tool, numerical–experimental procedure was defined in the paper. It showed that the consid- ered constructions failed due to incorrect operational parameters related to vibrations of structures. Appropriate strength diagnostic gave solutions for rehabilitation and recon- struction. The analysis was done using computer calculation, finite element method, with the required experimental measurements. This enabled determination of the actual behav- iour of structure, reliable prediction of its response in exploitation, determination of the cause for unfavourable behaviour or failure, assessment of service life time of reliable exploitation and the level of revitalization. As exploitation problems develop mostly from improper geometry design, presented methodology is necessary in the engineering analy- sis. This approach is justified due to low costs with a high level of the results. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Behaviour and condition diagnostic of drive groups on belt conveyors is very important for making proper decisions about the exploitation and maintenance, revitalization and modernization of drives and other structure components. Therefore, the analysis of these structures must be carried out in good and proper way. This paper studies the interaction between a drive unit and a steel structure which gives the relation between their eigen frequencies and a correct work of the system. Drive units on 2nd BWE-BC-S system on Drmno open cast mine and on waste dump on Pljevlja open cast mine were used as the examples of behaviour and condition diagnostic. These units had problems linked to increasing of vibrations of struc- tures. It resulted in frequent delays due to the failure of electromotor, gear-box housing and its driving shaft. For example, before the reconstruction, at Drmno open pit, there were as many as thirteen replacements of electromotor and unplanned standstills during just one year. Belt conveyors are complex systems, which have usually operated in different modes. This requires an analysis between the type of the drive and its inclusion in the transport system [1]. Appropriate simulation demands the application of new 1350-6307/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.engfailanal.2012.01.001 ⇑ Corresponding author. E-mail address: tmaneski@mas.bg.ac.rs (T. Maneski). Engineering Failure Analysis 22 (2012) 28–37 Contents lists available at SciVerse ScienceDirect Engineering Failure Analysis journal homepage: www.elsevier.com/locate/engfailanal