Hrvatske vode, Vol. 28 No. 114, 2020.
Original scientific paper
Analysis of mechanical characteristics of pipe material in embedded smooth pipes for purposes of developing technical and economic analyses
Luka Zaharija
; Hidromodeling d.o.o., Rijeka, Hrvatska
Davor Stipanić
; Hidromodeling d.o.o., Rijeka, Hrvatska
Danko Holjević
; Hrvatske vode, Rijeka, Hrvatska
Vanja Travaš
; Sveučilište u Rijeci, Građevinski fakultet, Rijeka, Hrvatska
Abstract
The content of the paper integrates the calculation procedures and computer algorithms that are purpose-built to solve and optimise a problem where, for a relatively large number of default input parameters, the optimal material for embedded pipes should be selected on the basis of criteria determined not only by technical conditions but also by economic conditions related to the return on investment in the designed exploitation period, i.e. life of a structure. To this end, it was primarily necessary to set the problem within a stochastic analysis where all relevant parameters were given in the form of probability density functions. This lead to the application of the classical Monte-Carlo method. However, this was insufficient for the analysed mechanical system since the analysed mechanical system was characterized, in the statistical sense, as a system with a small failure probability. In order to facilitate a stochastic analysis of such system, it was necessary to implement the Subset method, which introduced the transitional criteria of failure and the final probability of failure quantified by a procedure where input values were successively adapted through the Markov chains and modified Metropolis–Hastings algorithm. The criteria of failure included pipe wall corrosion, change in deflection of the pipe top, buckling of the pipe wall, exceedance of the pipe material yield point and critical stress exceedance during pipe bending. The probability of failure analysis was followed by economic analysis. It is all listed at the end of the paper and applied to an illustrative example.
Keywords
Hrčak ID:
254500
URI
Publication date:
30.12.2020.
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