scholarly journals Manufacturing, integration, and mechanical verification of SOXS

Author(s):  
Matteo Aliverti ◽  
Luca Oggioni ◽  
Matteo Genoni ◽  
Giorgio Pariani ◽  
Ofir Hershko ◽  
...  
2009 ◽  
Vol 25 (1) ◽  
pp. 109-127 ◽  
Author(s):  
Andrzej Gębura ◽  
Tomasz Tokarski

The Monitoring of the Bearing Nodes with Excessive Radial Clearances Using the FAM-C and FDM-A Methods The paper has been intended to present findings resulting from the monitoring of the bearing support elements with increased radial clearances with the FAM-C1 and FDM-A2 methods. The role the lubricant film plays in this type of the rolling-elements' wear has been described. Discussed are symptoms, parameters, and hazards to the resonant state in bearing nodes, as well as capabilities of diagnosing them with the FAM-C and FDM-A methods. Hypotheses about subsequent stages of the wearing process in aircraft turbojet engine's bearing support assemblies, including how the resonant state occurs, have been presented. The mechanism of the resonance in rolling-element bearings has been described, with particular attention paid to the effects of gyrostatic moments upon the bearing support elements, both in micro- and macro-scale. Theoretical analyses have been supplemented with findings resulting from the diagnostic work carried out by the Authors, and with data from the mechanical verification of engines in the course of the authorised dismantling thereof.


2021 ◽  
Author(s):  
◽  
Timothy James McKenzie Makarios

<p>This thesis describes the mechanization of Tarski's axioms of plane geometry in the proof verification program Isabelle. The real Cartesian plane is mechanically verified to be a model of Tarski's axioms, thus verifying the consistency of the axiom system. The Klein–Beltrami model of the hyperbolic plane is also defined in Isabelle; in order to achieve this, the projective plane is defined and several theorems about it are proven. The Klein–Beltrami model is then shown in Isabelle to be a model of all of Tarski's axioms except his Euclidean axiom, thus mechanically verifying the independence of the Euclidean axiom — the primary goal of this project. For some of Tarski's axioms, only an insufficient or an inconvenient published proof was found for the theorem that states that the Klein–Beltrami model satisfies the axiom; in these cases, alternative proofs were devised and mechanically verified. These proofs are described in this thesis — most notably, the proof that the model satisfies the axiom of segment construction, and the proof that it satisfies the five-segments axiom. The proof that the model satisfies the upper 2-dimensional axiom also uses some of the lemmas that were used to prove that the model satisfies the five-segments axiom.</p>


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