Téma diplomové práce je zaměřeno na metodiku charakterizace autoemisního zdroje pro elektronový mikroskop. Použitá metoda – Fowlerova-Nordheimova analýza je založená na přítomnosti kvantového tunelování, ke kterému dochází v průběhu autoemise elektronů. Práce je obsahově dělena na teoretický úvod do problematiky a praktickou část. Teoretický úvod popisuje emisi elektronů, kvantové tunelování a vlastnosti emisních zdrojů. Druhá část diplomové práce se věnuje experimentální analýze autoemisní katody. Součástí analýzy je výpočet základních charakteristik této katody. Vypočtené hodnoty stanovují celkovou kvalitu elektronové emise a zároveň poskytují informace o aktuálním stavu autoemisní katody. Výsledky F-N analýzy jsou poté srovnány s výsledky počítačové simulace autoemise elektronů. Simulace je provedena v programu COMSOL Multiphysics, který k výpočtu používá metodu konečných prvků a je nástrojem pro hodnocení významu a přesnosti Fowlerovy-Nordheimovy analýzy.

This master thesis deal with design of elevator cabin frame. Working load of frame is 630 kg (8 people). Speed of elevator is 1m/s. This work also contains final element analysis of frame. Frame structure is analyzed by software I-DEAS.

This thesis deal with stress control of frame of crushing mill of grain with the aim of defining and consequent optimalization of undersized and overlarge parts of the construction. This frame is screwed assembly. Control is static analysis of frame. This analysis use Finite Element Method.

This diploma thesis deals with design of a frame of a lift, whose roading capacity is 400 kg (5 people) and it olso deals with calculation of maximum distance between armatures of quides. Nominal speed is 1 m.s -1. This diploma thesis also includes final element analysis of the frame. The frame structure is analysed by software I – DEAS.

Calculating frame of elevator cage 1000kg, suggestion changes of frame according to calculation from MKP.

This diploma thesis deals with the design of disability traction elevator cabin OTI 630 / 0,63. In addition, the mounting procedure of the cabin, the calculation of the floor frame finite element metod in the program I-DEAS and the creation of drawings.

The subject of this master’s thesis is strength analysis of trailer frame, for platform placed goods and palletized goods transport. Strength analysis is made by the finite element method. This thesis describes design of a frame, finite element model creation and results analysis. On the basis of this results, the structural modification with a stress state calculation are suggested.

Motivation of this master‘s thesis is solution of practical problem of the newly developed slewing ring for tram Škoda, type: 15T. Next impulse for thesis creation was the possibility to extend product range of roller bearing ZKL. There is processed strain – stress analysis of bearing inner design making use the finite element method (FEM). Obtained results are compared with classic approach based on the Hertz theory. Important aim of this work is three main parameters optimal establishment: rolling element diameter, arrangement radius and number of rolling elements. Optimization job is realized by solutions of direct tasks with different parameters. With regard to necessity of detailed stress analysis and conservation of reasonable computational time it was chosen approach of combination global and local FEM model. It was used pre/postprocessor PATRAN and solver MARC for solution of strain and stress analysis. Analytic solution was accomplished in software EXCEL.

In this thesis the problem of optimizing the dimensions of the base frame molds for casts with FEM and for 4 weight classes, ie casts weighting 1, 3, 5 and 10 tons is solved. For the evaluation of the FEM ANSYS program was used. There are gradually presented optimization procedures for all four weight classes. There was established the persistence of forms and frame and at the end the conclusion of the technical-economic evaluation of the proposed forms in terms of material savings in comparison to the current state of production was made.

There are many shape and other changes in the engineering constructions. These changes cause the concentration of the stress. There is a higher probability of the crack initiation in the vicinity of these stress concentrators. The problems of the crack can be solved nowadays only with help of sufficient numeric tools. The Boundary Element Method is one of the many numerical tools which offer the solution of some problems of the mechanics. The goal of this diploma thesis is to formulate boundary element method for the plane problem of the linear elasticity for izotropic material with different types of the stress concentrators.