Publication detail
On the Mechanism of Factory-Roof Formation
POKLUDA, J. SLÁMEČKA, K. ŠANDERA, P.
Czech title
On the Mechanism of Factory-Roof Formation
English title
On the Mechanism of Factory-Roof Formation
Type
conference paper
Language
en
Original abstract
The investigated factory-roof (F-R) patterns were produced by cyclic torsion loading of V-notched cylindrical specimens made of the high-strength low-alloy steel. A three-dimensional model of the F-R pattern was constructed by means of the stereophotogrammetry. This allowed us to recognize the geometrical proportions as well as to understand the basic geometrical rules of its formation. The theoretical analysis revealed that the F-R initiates by elementary mode I branches at the front of semi-elliptical surface cracks. The exact positions of such branches can be analytically determined in terms of the maximum synergy of mode II and mode III loadings. An increasing density of semi-elliptical cracks initiated on the surface results in the refinement and the size reduction of F-R patterns. This effect can, together with strong wear damage, explain the fact that the F-R patterns are usually not observed in the low-cycle fatigue region.
Czech abstract
The investigated factory-roof (F-R) patterns were produced by cyclic torsion loading of V-notched cylindrical specimens made of the high-strength low-alloy steel. A three-dimensional model of the F-R pattern was constructed by means of the stereophotogrammetry. This allowed us to recognize the geometrical proportions as well as to understand the basic geometrical rules of its formation. The theoretical analysis revealed that the F-R initiates by elementary mode I branches at the front of semi-elliptical surface cracks. The exact positions of such branches can be analytically determined in terms of the maximum synergy of mode II and mode III loadings. An increasing density of semi-elliptical cracks initiated on the surface results in the refinement and the size reduction of F-R patterns. This effect can, together with strong wear damage, explain the fact that the F-R patterns are usually not observed in the low-cycle fatigue region.
English abstract
The investigated factory-roof (F-R) patterns were produced by cyclic torsion loading of V-notched cylindrical specimens made of the high-strength low-alloy steel. A three-dimensional model of the F-R pattern was constructed by means of the stereophotogrammetry. This allowed us to recognize the geometrical proportions as well as to understand the basic geometrical rules of its formation. The theoretical analysis revealed that the F-R initiates by elementary mode I branches at the front of semi-elliptical surface cracks. The exact positions of such branches can be analytically determined in terms of the maximum synergy of mode II and mode III loadings. An increasing density of semi-elliptical cracks initiated on the surface results in the refinement and the size reduction of F-R patterns. This effect can, together with strong wear damage, explain the fact that the F-R patterns are usually not observed in the low-cycle fatigue region.
Keywords in Czech
factory roofs; únava; krut; V-vrub
Keywords in English
factory roofs; fatigue; torsion; V-notch
RIV year
2009
Released
01.10.2009
Publisher
University of Parma
Location
Vicenza, Italy
ISBN
0000000000000
Book
Crack Paths
Pages from–to
155–166
Pages count
12
BIBTEX
@inproceedings{BUT30037,
author="Jaroslav {Pokluda} and Karel {Slámečka} and Pavel {Šandera},
title="On the Mechanism of Factory-Roof Formation",
booktitle="Crack Paths",
year="2009",
month="October",
pages="155--166",
publisher="University of Parma",
address="Vicenza, Italy",
isbn="0000000000000"
}