|
|
Proposal of welds number reduction on aluminium aloys frame doors for rail vehicles
Šplíchal, Jan ; Vaněk, Mojmír (referee) ; Sigmund, Marian (advisor)
This Diploma thesis presents possible proposals of welds number reduction frame doors for rail vehicles welded from profiles from aluminium alloy EN AW 6060, which is heat treated by temper T66. Profiles are welded by TIG process with additional material S Al 5087 (AlMg4,5MnZr). The heat treatment by the welding cycle causes a change in structure of basic material and decrease of mechanical properties due to dissolution of precipitates. To measure the necessary mechanical properties of the material after welding a tensile test was performed on the delivered samples. The resulting values from tensile test were subsequently used as cut – off values in the new door frame design by FEM simulation in Virtual Performance Solution software with PAM – Crash extension. The newly designed frame was welded according to the necessary welding procedure specifications, which are also part of the thesis. The conclusion is devoted to the economic evaluation of the current and new design of the door frame.
|
|
|
Analysis of the Production Processes Influence on Rail Deformations
Skalník, Vít ; Podaný, Kamil (referee) ; Vaněk, Mojmír (advisor)
The aim of this work is to assess the possibilities of using numerical simulation tools in the process of laser welding of the guide rail of a car seat. In the diploma thesis, a description of the components and the problem, which consists in the deformation of the groove of the guide rail, was made. A description was made of the manufacturing operations that the components go through. The positives of selected welding methods were evaluated and the choice of those used in production was justified. A description of the issues of laser welding, deformation and the use of simulation tools was made. The influence of individual production operations was evaluated in terms of the size and nature of deformations. Using the Visual – Mesh, Visual – Weld and Visual – Assembly simulation tools, which are products of the French company ESI Group, the same state of the simulated and real process was achieved. Subsequently, a proposal for the elimination of deformations and its verification using a simulation tool could be approached. The use of a spacer wedge, which acts on the most deformed places of the groove, was proposed. By its application, the resulting deformations were eliminated or significantly reduced. In the last part of the work, a technical and economic evaluation was made, taking into account the current global crisis and the important role of the automotive industry.
|
|
|
Synthesis and biological evaluation of novel uncharged cholinesterase reactivator against nerve agent intoxication
Vaněk, Mojmír ; Roh, Jaroslav (advisor) ; Krátký, Martin (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Organic and Bioorganic Chemistry Student: Mojmír Vaněk Supervisor: doc. PharmDr. Jaroslav Roh Ph.D. Advisors: PharmDr. Jan Korábečný Ph.D.; PharmDr. Vendula Hepnarová Ph.D. Title of diploma thesis: Synthesis and biological evaluation of novel uncharged cholinesterase reactivator against nerve agent intoxication Nerve agents (NPL) and pesticids are strongly toxic organophosphorus compounds with high affinity to acetylcholinesterase (AChE) enzyme. This enzyme is present in CNS and neuromuscular synapses. The intoxication leads into an acute cholinergic crisis, which can ultimately results into death. The therapy must be quick and includes application of atropine, reactivators of AChE and diazepam. Among the commonly used AChE reactivators, mono- or bis- quarternary aldoximes cen be found. These compounds are permanently charged, so their penetration through the blood-brain barrier (HEB) is very limited (up to 10 %, often only 1-3 %). Within the diploma thesis, a non quarternary AChE reactivator has been developed by multiple-steps synthesis approach. This compound, denoted as K1396, would exert high ability to penetrate through HEB. In vitro assessments of his capability to reactivate AChE has been carried out by method of Ellman....
|
|
|
Loss of strength during welding aluminous alloys AW 6060
Sklenář, Martin ; Vaněk, Mojmír (referee) ; Sigmund, Marian (advisor)
The aim of the bachelor thesis is to qualify the welding procedure according to the standard ČSN EN ISO 15614-2. At the beginning of the work is introduced a company with which was this thesis made. This is followed by an assessment of the issue of aluminum. Furthermore, the mechanical properties of aluminum are discussed. Follows by part about welding specially about aluminium welding. In the practical part the samples were welded and subsequently evaluated, then the design and qualification of the welding process was made. In conclusion, the possibilities and results that have been achieved are summarized.
|
|
|
Stick welding carbon and high-alloy steels
Hendrych, Marek ; Vaněk, Mojmír (referee) ; Kubíček, Jaroslav (advisor)
This thesis deals with analysis of manual metal arc welding method or method 111. In the research part of this thesis are discused principles of this method, welding power sources and additional welding material-coated elecrodes. Further the thesis is focused on the weldability of steels, especially carbon steels and austenitic stainless steels. In the experimental part was accomplished measurement of operational characteristics of coated electrods. Measurement was carried out on sample of cabon steel S235JR according to ČSN EN and austenitic stainless steel X5CrNi18-10 accordig to ČSN EN. The evaluation envolves a comparison of the results and their justifications.
|
|
|
Proposal of welds number reduction on aluminium aloys frame doors for rail vehicles
Šplíchal, Jan ; Vaněk, Mojmír (referee) ; Sigmund, Marian (advisor)
This Diploma thesis presents possible proposals of welds number reduction frame doors for rail vehicles welded from profiles from aluminium alloy EN AW 6060, which is heat treated by temper T66. Profiles are welded by TIG process with additional material S Al 5087 (AlMg4,5MnZr). The heat treatment by the welding cycle causes a change in structure of basic material and decrease of mechanical properties due to dissolution of precipitates. To measure the necessary mechanical properties of the material after welding a tensile test was performed on the delivered samples. The resulting values from tensile test were subsequently used as cut – off values in the new door frame design by FEM simulation in Virtual Performance Solution software with PAM – Crash extension. The newly designed frame was welded according to the necessary welding procedure specifications, which are also part of the thesis. The conclusion is devoted to the economic evaluation of the current and new design of the door frame.
|
|
|
Influence of shape of the electrode to weld pool
Hrádek, Jan ; Vaněk, Mojmír (referee) ; Kubíček, Jaroslav (advisor)
The project is focused on welding of TIG method. In this method is used non-melting tungsten electrode, which can have different top angles. In different literature there are different opinions about how angle influence weld pool. It was sharpen six different angles of electrode with whom was done welds on carbon steel S235JR and on austenitic corrosion resistant steel x5CrNi1810. The evaluation was done with help of chart where on the axis x is angle of electrode and on axis y are depth and width weld in millimiters. The result of this project was the prove of opinion that with more sharper angle of electrode is depth of weld smaller and width bigger.
|
|
|
Technological process of forging die repair
Kriegsmann, Luděk ; Vaněk, Mojmír (referee) ; Kubíček, Jaroslav (advisor)
The bachelor thesis presents a proposal and solution of renovation of forging insert, which is made of tool steel 1.2367. Due to the literature search, manual electric arc welding with coated electrode was chosen for renovation. The work deals with the stress of the forging insert, which was carried out by strength and thermal analysis. After performance of trial overlay by several coated electrodes, hardness measurement and calculation of dilution of materials was performed. Based on these results, electrode Capilla 66 was selected. Renovation of insert was performed according to preliminary technological process pWPS. The Insert was preheated to 300 °C. As a power source was used TransPocket 3500 and welding current was 190 A.
|
|
|
Welding of the sanitary gully
Skalník, Vít ; Vaněk, Mojmír (referee) ; Kubíček, Jaroslav (advisor)
The aim of this paper is to plan out and realize an optimalization for the welding process of parts of a sanitary gully. Problematics during the welding process of the aforementioned parts together with the usage of welding fixture were explained. On the basis of characteristic signs of welding, an application of other methods was evaluated and the optimal option for the welding process was chosen. During the selection process, hygienic regulations of a non-state funded organization EHEDG (European Hygienic Engineering and Design Group) were taken into account. Furthermore, suggestions for adjustments of the welding process of the forefront of the gully were analyzed. The next step was the realization of the chosen plan and its testing. Part of the process was the implementation of a technological procedure and execution of WPS (Welding Procedure Specification). The end of this paper considers the tecnological-economic contributions of the changed in the procedure.
|
|
|
Development of Models of Al Alloys Behaviour for Applications in Numerical Simulations of Welding and Heat Treatment
Vaněk, Mojmír ; Věchet, Stanislav (referee) ; Neumann, Heinz (referee) ; Daněk, Ladislav (advisor)
The thesis deals with methodology for computational approaches for numerical simulations of welding and heat treatment of aluminium alloys. The thesis describes improvement of the current methodology for metallurgical part of the numerical analysis of welding, which is important mainly for prediction of dimensions of the heat affected zone (and deformations). The improvement was carried out based on CHD diagram that describes precipitation and dissolution of phases during continuous heating. The thesis also describes carried material measurements (measurement of chemical composition, dilatometric tests, tensile tests of several conditions of materials at temperatures up to 500 °C and measurement of aging curves), which allowed to significantly refine analysis results for the alloys EN AW-5083 and EN AW-6082. Based on an evaluation of the measurements, several conclusions were made. They can be useful for creation of material databases of other aluminium alloys. The thesis also describes quantification of dependence between tensile strength and yield strength on the Vickers hardness for different conditions of EN AW-6082. There is also methodology for numerical simulation of the heat treatment process of heat treatable Al alloys in the dissertation. The methodology is completely new approach which has never been published so far. Application of this method is based on user changes of the material database in software Sysweld after relatively easy measurement of aging curves. Therefore, the methodology can be considered as promising for application in industrial practice.
|
guest ::
RSS feed.