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Analysis of the procedure for identifying potentially dangerous locations of weld joints in thin-walled metal structures during life assessment
Doležel, Daniel ; Pavlík, Ondřej (referee) ; Vosynek, Petr (advisor)
Hodnocení únavy svarů u tenkostěnných kovových konstrukcích je klíčové pro zajištění integrity navrhovaných konstrukcí. Navzdory zavedeným kritériím a S-N křivkám může být analýza životnosti svařovaných spojů u geometricky komplexních součástí značně komplikovaná. Hlavní překážkou je identifikace kritických míst z hlediska únavy pro detailní výpočet, což může být časově náročné i při využití metody konečných prvků (MKP). Tato práce podrobně zkoumá hodnocení únavy svarů, zahrnuje vhled do relevantní literatury, komerčních řešení a praktický kontext norem železničního průmyslu a směrnice FKM. Významným přínosem práce je vývoj automatizovaných FEMAP API programů pro MKP software Siemens FEMAP, které usnadňují proces analýzy. Tyto programy šetří čas a úsilí tím, že umožňují zjednodušenou analýzu založenou na konceptu lokálního nominálního napětí (local nominal stress) v souladu se směrnicí FKM. Metodika, podpořená vyvinutými programy, je v této práci popsána a prakticky demonstrována. Praktické přínosy této práce spočívají v poskytnutí alternativy ke komerčním softwarům, za účelem zvýšení efektivity analýzy životnosti svarů v kontextu konstukčních návrhů.
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Weldet constructions in technical documentacion
Bartošek, Daniel ; Brandejs, Jan (referee) ; Svoboda, Pavel (advisor)
The presented bachelor´s thesis deals with design documentation of welded con-structions. It provides an overview of weldment design types, basic usage principles and formal prerequisits. The thesis should serve for education of weldment design documentation, for which purpose the set of tasks included in the annex was also created.
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Non-destructive testing of welds
Šaloun, Jan ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
This thesis describes non-destructive testing (NDT) of fusion welds of metals. There are five fundament methods of NDT discussed in the theoretical part – visual and magnetic particle inspection, ultrasonic, radiography and penetrant testing. Principles of methods, examining procedures and their evaluations are described. The methods are compared with each other. In the experimental part of the thesis two samples of welding joints were welded and tested by selected methods. To verify correctness of the indicated defects, metallographic samples were made. At the conclusion practical results are compared with theoretical statements.
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The roof structure of a bus station with facilities in Vrchlabí
Vondráček, Vít ; Hron, Lukáš (referee) ; Šmak, Milan (advisor)
The subject of bachelor's thesis is design and assessment of steel load-bearing construction of bus station in Vrchlabí. It is designed as a co-operating load-bearing steel pillar based structure with the construction of the outdoor platform. The design was considered in four different options for inner building. Followed was mainly the weight of inner structure with respect to the roof deck. The selected option is then incorporated into the scope of the entire structure. Design and assessment was conducted in accordance with the applicable standards and by using a computer program Scia Engineer.
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Comparative analysis of light holder lifetime assessment methods
Holeta, Aleš ; Pokorný, Jan (referee) ; Vosynek, Petr (advisor)
This thesis addresses the topic of determining the fatigue life of a thin-walled holder fender and flashlight under variable loads. The aim of the thesis is to make a search study on the fatigue life of welded parts with respect to the thin-walled design of structures. The main objective is to evaluate the suitability of using different methods of fatigue life assessment on the holder fender and flashlight. The calculated fatigue lifetimes are confronted with experimentally obtained fatigue life-times. The fatigue lifetimes are determined by methods evaluating welded joints based on structural stresses and notch stresses. Finite element analysis was performed in the open-source programs Salome and Code_Aster. The modelling of the holder fender and flashlight geometry was performed at several levels. Based on the results, the most efficient method for the design of welded parts is the structural stress linearization method (also called “master S-N curve method”), which achieves comparable results to the effective notch stress method (considered as a reference), but with a multiply lower time consumption.
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