Papers by Dobrivoje Ćatić
Proceedings on Engineering Sciences, 2019
Using the Fault Tree Analysis method -FTA, an analysis of the potential failure modes of the elem... more Using the Fault Tree Analysis method -FTA, an analysis of the potential failure modes of the elements of the crop sprayer pump Comet BP 105 was carried out in this paper. In order to conduct a detailed analysis of the causes and failure modes of a pump, it is necessary to know the structure, the way of operating and the interrelationship of the constituent elements. Based on the collected data, the fault tree of the considered object was formed. In this way, the cause-and-effect relationship between failures of structural entities of different levels of affiliation is established. In conclusion of the paper, the importance of applying the fault tree analysis to improve the efficiency of the existing systems and the quality in the development of similar design solutions is pointed out.
Strojniški vestnik – Journal of Mechanical Engineering, 2011
FME Transactions, 2009
The paper presents the principles of calculation and design of crane's trolley intended to w... more The paper presents the principles of calculation and design of crane's trolley intended to work with a two-rope grab having drive elements for moving and hoisting. The trolley moves along the lower girdle of the bridge crane. Mechanism for grab hoisting with two electric motors connected by a planetary reduction gear is considered. The role of the planetary reduction gear in selected solution for load hoisting drive is specially emphasized and calculation of main parameters of this gear is given. Operation principles of the grab's ...
Journal of the Balkan Tribological Association
ABSTRACT
Journal of the Balkan Tribological Association
Procedures for planning of truncated tests for reliability assessment and process-ing of test res... more Procedures for planning of truncated tests for reliability assessment and process-ing of test results are presented in the paper, using the case of the tie-rod joint belonging to the steering system of light commercial vehicle. in order to select and quantify the optimum plan for testing the observed object, it is necessary to know in detail the structure, the way of operation, the causes of potential failure modes and mechanisms of their generation. statistical data set related to the op-eration time until failure on tie-rod joint occurrence is gained by conducting tests in exploitation conditions. test results processing is done using computer and cor-responding software. selection of optimum theoretical model of random variable distribution is conducted with taking into account all relevant identifiers.
Tribology in Industry
A B S T R A C T The introduction of the paper gives the basic concepts, historical development of... more A B S T R A C T The introduction of the paper gives the basic concepts, historical development of methods of Fault Tree Analysis -FTA and Failure Modes, Effects and Criticality Analysis -FMECA for analysis of the reliability and safety of technical systems and importance of applying this method is highlighted. Failure analysis is particularly important for systems whose failures lead to the endangerment of people safety, such as, for example, the braking system of motor vehicles. For the failure analysis of the considered device, it is necessary to know the structure, functioning, working conditions and all factors that have a greater or less influence on its reliability. By formation of the fault tree of drum brakes in braking systems of commercial vehicles, it was established a causal relation between the different events that lead to a reduction in performance or complete failure of the braking system. Based on data from exploitation, using FMECA methods, determination of the cri...
In the introductory part of the paper, the importance of using the FTA method for analysis of the... more In the introductory part of the paper, the importance of using the FTA method for analysis of the reliability and safety of technical systems is pointed out. An analysis of the failure of the light commercial vehicles' steering system by application of FTA method is performed in this paper. Based on available data, by the team approach, the fault tree of steering system is developed. The procedure of forming the minimal cut sets for the concrete example is explained. By analysis of the common cause ranking of secondary causes of basic fault tree events, according to their influence on the system failure occurrences, was performed, and the possibility of eliminating the causes of failure was considered. In conclusion, the paper presents possible applications of the achieved results. Keywords: Fault Tree Analysis, industrial light vehicle, steering system, qualitative
Reliability allocation represents an integral part of reliability design of technical systems and... more Reliability allocation represents an integral part of reliability design of technical systems and their parts. The detailed explanation of a computer program refers to reliability allocation methods from a standpoint of technical requirements are given in this paper. Reliability allocation is shown on a specific example using the AGREE method. Advantages of an automated approach to reliability allocation and the direction of further development of the presented program are shown in the conclusion of the paper.
The K2S is machine for sorting and packing potatoes. Exploitation of this machinery so far point ... more The K2S is machine for sorting and packing potatoes. Exploitation of this machinery so far point to some weakness of it. The K2S machine consists of one belt conveyer, which is used to transport potatoes to oscillating transporter, and two oscillation transporters, which is used for sorting potatoes. This paper presents using of dynamic fault tree method in order to make revision proposal of K2S. Revision of K2S should provide incision of the capacity, removing the weaknesses, and prolonging of the machine life cycle. The dynamic fault tree method is chosen among other methods because of its ability to put events in time order. This paper also shows old design, dynamic fault tree of the oscillation system and proposal of the machine revision. Paper concludes with the discussion of the achieved results. At the end of the paper other possible directions of improving machine design are given.Mašina K2S je mašina koja služi za klasiranje i pakovanje krompira. Dosadašnja eksploatacija ove mašine ukazala je na neke njene nedostatke. Mašina K2S se sastoji od jednog trakastog transportera koji služi za dodavanje i dva oscilatorna transportera koja služe za klasiranje krompira. U ovom radu je korišćenjem dinamičke analize stabla otkaza napravljen predlog revizije mašine u cilju povećanja njenih kapaciteta, otkalanjanja nedostataka i produžavanja radnog veka. Dinamička analiza stabla otkaza je izabrana pored ostalih metoda pouzdanosti zbog njene mogućnosti za uračunavanje redosleda događaja otkaza. U radu su dati prikazi stare mašine, dinamička analiza stabla otkaza sistema za pobudu oscilacija kao i predlog revizije mašine. Na kraju rada izvršena je diskusija postignutih rezultata i dati su pravci mogućeg daljeg unapređivanja ove mašine
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2014
The paper gives a numerical procedure for determining the reliability, based on known theoretical... more The paper gives a numerical procedure for determining the reliability, based on known theoretical models for distribution of the working stress and the corresponding mechanical properties of materials. The procedure is based on one of the transformed forms of the general equations for the analytical determination of reliability. Along with a presentation of the method, a detailed explanation is given of the algorithm that the created computer program is based on. The verification procedure is performed as an example for a combination of normal distributions of the working and the critical stresses. At the end of the paper is presented a discussion on impact of each of the factors that influence the accuracy of solutions of the considered method.
Thermal Science, 2011
Paper presents stress calculation in the stationary temperature domain for a hybrid structure wit... more Paper presents stress calculation in the stationary temperature domain for a hybrid structure with standard epoxy-carbon fiber composite and metallic part, showing different thermal behaviour. The thermal stress analysis is based on the finite element method. A sample problem involving such a composite plate and metallic part of structure or mould at two different temperature levels, corresponding to curing process (co-curing) and operating temperatures, respectively, is calculated and discussed. The specific properties of composite are emphasized particularly for thermal coefficients, especially if the shear coefficient is different than zero, causing completely different behaviour compared to isotropic materials.
Structural and Multidisciplinary Optimization, 2012
ABSTRACT The paper considers the problem of optimization of the box section of the main girder of... more ABSTRACT The paper considers the problem of optimization of the box section of the main girder of the bridge crane. Reduction of the girder mass is set as the objective function. The method of Lagrange multipliers was used as the methodology for approximate determination of optimum dependences of geometrical parameters of the box section. The criteria of permissible stresses and strains, lateral stability and dynamic stiffness were applied as the constraint functions. The obtained results of optimization of geometrical parameters were verified on numerical examples and the comparison with some solutions of cranes was made. The comparative analysis of the optimization results and the solutions was the basis for recommendations which are significant for designers during construction of cranes.
International Journal of Vehicle Design, 2014
The historical development is presented in the introductory part and it points out the importance... more The historical development is presented in the introductory part and it points out the importance of using the Fault Tree Analysis (FTA) method for analysis of the reliability and safety of technical systems. By analysing a number of references related to the FTA method, a FTA methodology is established, whose algorithm, with explanation of some steps, is given in this paper. As an example of the practical application of the method, the fault tree of the hydraulic power booster of the steering system of light commercial vehicles is qualitatively analysed. Based on data from the development phase and through a team approach, a fault tree for hydraulic power steering was developed. Along with an explanation of certain parts of the fault tree, the estimation of significance of certain events is done and the possibilities are considered to eliminate causes of failure or to minimise the consequences of failure.
In the introductory part, the history development is presented, and it points out the importance ... more In the introductory part, the history development is presented, and it points out the importance of using the Fault Tree Analysis -FTA method for analysis of the reliability and safety of technical systems. By analyzing a number of references related to the FTA method, the FTA methodology is established, and explanation of some steps by this method is given in this paper. As an example of the practical application of methods, the failure of the solar concentrators is analyzed.For the failure analysis of the considered device, it is necessary to know the structure, functioning, working conditions and all factors that have a greater or less influence on its reliability. Along with an explanation of certain parts of the fault tree, the estimation of the significance of certain events is done, and it is considered to be able to eliminate causes of failure or to minimize the consequences of failure.
Proceedings on Engineering Sciences, 2019
The description of the fault tree analysis is given in the introductory part of the paper, and it... more The description of the fault tree analysis is given in the introductory part of the paper, and it is pointed out the significance of the system for braking motor vehicles on the safety of people in traffic. A brief overview of the methodology of this method is then followed. The basic structure and the function of each subsystem during realization of given tasks are given in the part of the paper related to the brake system. Considering the example of the total failure of the brake system, it has been shown how to acquire a block-diagram of the observed system's reliability based on the formed fault tree. In order to be acquainted with the brake system from the aspect of failure occurrence and to record the largest possible number of potential failure modes of the constituent elements, the fault tree for the peak event "Reduction of the performance of the brake system" has been formed. In conclusion, the paper presents possible applications of the achieved results.
Uploads
Papers by Dobrivoje Ćatić