Modelling of thermal stresses in bearing steel structure generated by electrical current impulses

Author(s):  
Mihails Birjukovs ◽  
Andris Jakovics ◽  
Walter Holweger
2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Josip Sertić ◽  
Dražan Kozak ◽  
Ivan Samardžić

The values of reaction forces in the boiler supports are the basis for the dimensioning of bearing steel structure of steam boiler. In this paper, the application of the method of equivalent stiffness of membrane wall is proposed for the calculation of reaction forces. The method of equalizing displacement, as the method of homogenization of membrane wall stiffness, was applied. On the example of “Milano” boiler, using the finite element method, the calculation of reactions in the supports for the real geometry discretized by the shell finite element was made. The second calculation was performed with the assumption of ideal stiffness of membrane walls and the third using the method of equivalent stiffness of membrane wall. In the third case, the membrane walls are approximated by the equivalent orthotropic plate. The approximation of membrane wall stiffness is achieved using the elasticity matrix of equivalent orthotropic plate at the level of finite element. The obtained results were compared, and the advantages of using the method of equivalent stiffness of membrane wall for the calculation of reactions in the boiler supports were emphasized.


2018 ◽  
Vol 157 ◽  
pp. 02024 ◽  
Author(s):  
Bohuš Leitner ◽  
Lucia Figuli

Problems of fatigue life prediction of materials and structures are discussed in the paper. Service loading is assumed as a continuous loading process with possible discontinuous events, which are caused by various operating conditions. The damage in a material is due to a cumulative degradation process. The damaging process is then represented either by rain-flow matrices or by a fatigue damage function which is derived using some hypothesis of a fatigue failure criterion. Presented theoretical procedure enables a very effective estimation of a service life and/or reliable evaluation of residual life of any structures under various types of loading and environmental conditions. This approach creates a good basis for powerful expert systems in structural and mechanical engineering. The aim of the paper is to present briefly some results of analysis of load-bearing steel structure loads of special railway crane PKP 25/20i which was utilized in some specific ad relatively hard operating conditions. Virtual models of the structure were being used in an analysis of acting working dynamics loads influence to be able to forecast fatigue life of load-bearing of the crane jib.


1960 ◽  
Vol 82 (2) ◽  
pp. 302-306 ◽  
Author(s):  
Richard C. Drutowski ◽  
Ernie B. Mikus

The rolling friction, contact plastic deformation, and elastic limit were determined for SAE 52100 steel structures with retained austenite contents from zero to 18.4 per cent. The force necessary to roll a ball on a plate decreased as the retained austenite was decreased. The contact stress necessary for the initiation of plastic deformation and the elastic limit of the material increased as the retained austenite content decreased from 18.4 to 3.9 per cent. No further change occurred when the retained austenite was reduced to zero. The extent of plastic deformation at very high contact stresses was reduced by the presence of retained austenite contents up to at least 7.4 per cent. These observations were applied to the problem of selecting the best steel structure for an instrument ball bearing.


2011 ◽  
Vol 18 (4) ◽  
pp. 1203-1211 ◽  
Author(s):  
Predrag D. Jovančić ◽  
Dragan Ignjatović ◽  
Miloš Tanasijević ◽  
Taško Maneski

2006 ◽  
Vol 12 (2) ◽  
pp. 118-123
Author(s):  
Valentinas Skaržauskas ◽  
Valentin Jankovski ◽  
Juozas Atkočiūnas

This paper presents the analysis of the spatial prismatic sloped overlay of irregular shape with a spherical surface upon. This bearing steel structure is under a dead‐load of a framed glass packet and under snow. Mathematical model of prism and spheroid geometry is developed. Construction geometry of a rectangularly profiled pipe and snow pressure is modelled in finite elements, using special software is developed by authors. This software is designed for the evaluation of glass structures and is easily adopted for a data exchange with commercial software. Computer aided design of the overlay and structure stress‐deformation analysis is realized by ANSYS.


2021 ◽  
Vol 145 ◽  
pp. 106078
Author(s):  
Benjamin Gould ◽  
Nicholas Demas ◽  
Robert Erck ◽  
Maria Cinta Lorenzo-Martin ◽  
Oyelayo Ajayi ◽  
...  

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