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Start Over Coverage 323-329

1. Monotone iterative technique and connectedness of the set of solutions

Creator:
Rudolf, Boris
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
order preserving operator, ordered Banach space, structure of the set of fixed points, fixed points between the minimal and maximal ones, and connectedness of the set of solutions
Language:
English
Description:
The paper deals with the properties of a monotone operator defined on a subset of an ordered Banach space. The structure of the set of fixed points between the minimal and maximal ones is described.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Stress analysis of the hip joint endoprosthesis with shape deflections

Creator:
Fuis, Vladimír and Návrat, Tomáš
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
computational modelling, hip joint endoprosthesis, micro-unevenness modelling, stress and failure probability analyses, and Weibull weakest link theory
Language:
English
Description:
The paper deals with the problems of ceramic head of hip joint endoprosthesis destructions, and with assessing the impact of shape deflections of conical surfaces on the probability of this failure. Concerned are shape deflections from the ideal conical surfaces of the stem and the head of the endoprosthesis, which - when the head is put on the stem and the endoprosthesis loaded - form a contact configuration. The shape deflections may be modelled at the macro-level - this concerns model shape inaccuracies such as deflection from the nominal degree of taper, ovality, and their combination, or, possibly, at the micro-level - when the stochastic distribution of unevenness on the contact areas is respected. The problem of stress in ceramic heads was solved using the algorithm of the finite element metod for spatial contact tasks, and the Weibull probability model was used for solving the problem of head cohesion failure probability. In the paper are presented and analysed the results of solution of the micro-level shape deflections, obtained from measurements made on the cones of stems and heads.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. The limits of the beam sag under influence of static magnetic and electric force

Creator:
Stein, George Juraj, Darula, Radoslav, and Chmúrny, Rudolf
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
clamped beam sag, electromagnetic actuator, sag approximation, thresh-old current, sag limit, and electrostatic case
Language:
English
Description:
Utilization of a magnetic force can be found in many mechatronic applications, where e.g. a slender beam or plate is subjected to static magnetic force generated by an electromagnetic actuator consisting of a solenoid wound on a ferromagnetic core and a ferromagnetic armature, fixed to the beam. The static magnetic force, acting perpendicularly onto the beam, causes sag (downwards bending) of the beam. If the magnitude of the magnetic force surpasses some threshold value the armature and hence the beam is completely attracted to the core of the solenoid. For small detections the mathematical expression of the magnetic force can be linearised and approximated by a polynomial dependence on the distance to the electromagnet. In practical application, it is important to analyse the nature of the sag and to determine the limits of the linear approxmation, as well as the limits leading to the full attraction to the electromagnet. The mathematical generalisation of the sag is valid for electrostatic force between planar electrodes, too. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public