This article deals with the non-destructive ultrasonic testing of split sleeve butt joints by ultrasonic methods. Split sleeve is used to repair gas pipelines with gas leakage. The new ultrasonic methods TOFD and Phased Arrays are compared considering to the selected butt weld configuration. To compare testing methods, ES Beam Tool software was used to prediction of ultrasonic beam spread through weld joint. TOFD technology was selected to butt weld section testing according to the beam spread simulation results. The results of ultrasonic testing by TOFD method were compared with results of macrostructural analysis of weld joint. Controlling the suitability of testing method to planar defect identification, the artificial defects were prepared and tested. The appropriate setting of measuring technique can be predicted from experimental results.

Fatigue behavior of the branch connection made of low-alloyed steel with yield stress of 355 MPa during low-cycle bending test is investigated in the article. Numerical prediction of the stress and strain distribution are described and experimentally verified by fatigue test of the branch connection sample. Experimental verification is based on low-cycle bending testing of the steel pipes welded by manual metal arc process and loaded by external force in the appropriate distance. Stresses and displacement of the samples induced by bending moment were measured by unidirectional strain gauges and displacement transducers. Samples were loaded in different testing levels according to required stress for 2.10 6 cycles. Increase of the stress value was applied until the crack formation and growth was observed. Results showed a high agreement of numerical and experimental results of stress and displacement.

Article deals with ultrasonic testing of the casting. It focuses on the problems that arise when testing of castings is made of non-ferrous metals. Theoretical introduction of article is dedicated to the most common types of casting defects and selecting technology for their reliable identification. The impact of the large anisotropic grain casting to propagate and attenuation of ultrasound it describes in theory. The examples of practical testing of Cu-alloy casting are presented in experimental part. Modern tools for simulation of ultrasound propagation in testing material were used for the correct setting techniques of UT testing as well as for the evaluation of the measurement results. Conventional direct contact ultrasound probe with frequencies of 5 MHz, 3.5 MHz and 2 MHz were used for all measurements. The results of experimental measurements referred in this article are recommendations for selecting equipment and accessories for casting testing made of non-ferrous metals.

NUMERICAL SIMULATION OF DISSIMILAR WELD JOINT IN SYSWELD SIMULATION SOFTWARE Radoslav Koňár, Marek PatekOriginal scientific paper Dissimilar weld joints are prone to frequent failures caused by many factors. Several methods might be used for prediction of the failures, from which prediction of the residual stresses and weld joint hardness plays a very important role. During the construction design, there is a possibility to predict residual stress by welding numerical simulation that may serve as the failure prevention. In presented article, residual stresses of dissimilar X5CrNi18-10/S355J2H weld joint were predicted by SYSWELD software after optimization of welding process by experimentally obtained thermal behaviour. The hardness wizard tool of the programme was employed for prediction of the weld joint hardness. Keywords: dissimilar weld; hardness prediction; residual stress; SYSWELD; temperature fieldNumerička simulacija zavarenog spoja od različitih materijala u simulacijskom programu SYSWELD Izvorni znanstveni članak Zavareni spojevi od različitih materijala podliježu čestim kvarovima zbog raznih faktora. Postoji nekoliko metoda koje se mogu primijeniti za predviđanje kvarova, a među njima vrlo važnu ulogu ima predviđanje zaostalih naprezanja i tvrdoće zavara. Tijekom dizajniranja konstrukcije, postoji mogućnost predviđanja zaostalog naprezanja numeričkom simulacijom varenja koja može služiti za prevenciju kvara. U ovom radu zaostala naprezanja zavarenog spoja X5CrNi18-10/S355J2H od različitih materijala predviđena su programom SYSWELD nakon optimizacije postupka zavarivanja eksperimentalno dobivenim toplinskim ponašanjem. Čudesni alat za tvrdoću iz tog programa upotrjebljen je za predviđanje tvrdoće zavarenog spoja.Ključne riječi: predviđanje tvrdoće; SYSWELD; temperaturno područje; zaostalo naprezanje; zavar od različitih materijala

This article deals with simulations of the welding process for applications of practice using SYSWELD software. Simulation of welding at the repair of high-pressure gas pipeline with steel sleeve with composite filling is presented in this paper. Two welds connecting the distance ring and gas pipe were simulated. Structure of programme SYSWELD and repair of high pressure gas pipeline with steel sleeve is described in theoretical part of article. Preparation of boundary conditions for numerical simulation on real sample and numerical simulation of welding is in experimental part. Thermal fields, residual stresses and hardness were simulated. The results of the numerical model, which are listed in article except for residual stresses are compared to real experiments. This article mainly describes the numerical simulation capabilities in welding simulation programme SYSWELD.