Fatigue and fracture of threaded connections

Published on Jan 1, 1994
· DOI :10.1016/B978-0-444-81645-0.50017-2
J. Toribio1
Estimated H-index: 1
Sources
Abstract
This paper presents stress intensity factor (SIF or K) solutions for a semi-elliptical surface crack in a bolt subjected to tension, bending, residual stresses and nut loading. Solutions were numerically computed by a 3D finite element method (FEM) with quarter-point singular isoparametric elements along the crack line. The stress intensity factor was calculated through the stiffness derivative method, by using a virtual crack extension technique to compute the energy release rate. SIF solutions for different loading conditions are given along the crack front related to the ratio of crack depth/bolt minor diameter and to the crack aspect ratio. A second order polynomial interpolation was carried out on the results, in order to provide analytical expressions useful for fatigue life predictions.
📖 Papers frequently viewed together
6 Citations
2 Citations
References71
Newest
Se ha estudiado el problema de la fractura de armaduras de acero en las que existe una fisura en forma de lunula, como es el caso de las generadas por fatiga o corrosion bajo tension. Utilizando los principios de mecanica de fractura se han llegado a establecer cinco criterios de fractura para alambres que permiten predecir el esfuerzo de traccion que provocara la rotura del alambre conocidos su estado de fisuracion y las caracteristicas del material que lo constituye. Cada uno de los criterios ...
25 Citations
Abstract An elliptical-arc surface crack in a round bar under cyclic axial loading with constant amplitude is considered. The stress-intensity factor along the crack front is calculated through a finite-element analysis by employing isoparametric solid elements. Then the fatigue crack propagation is examined by means of the Paris-Erdogan law. The aspect ratio a/b of the initial flaw is made to vary from 0.0 (straight crack front) to 1.0 (circular-arc crack front). Moreover, different material pr...
145 CitationsSource
The structural integrity and the reliability of sheet structures, especially those of high risk like pressure vessels and pipes, is a relevant topic which has centered the attention of many researchers. This paper offers an engineering approach to determine the fatigue life of sheet structures under cyclic loading. The theoretical development presents a general method for calculating, by using a micro-computer, the initiation and fracture loci and the two-parameter crack growth paths as well as ...
1 CitationsSource
The crack aspect ratio influence on the stress-intensity factor of elliptical-arc edge flaws in solid round bars under tension or bending loading is discussed. The relative crack depth ξ=a/D between the depth a of the crack's deepest point and the bar diameter D ranges from 0.1 to 0.6, while the aspect ratio a/b of the flaw is made to vary from 0.0 (straight crack front) to 1.0 (circular-arc crack front). For each value of ξ being considered, the maximum stress-intensity factor is attained in co...
89 CitationsSource
#1Andrea Carpinteri (UNIPD: University of Padua)H-Index: 44
Abstract An automated procedure is developed to determine the influence of a crack detected in a structural element subjected to cyclic combined axial and bending loadings with constant amplitude. A theoretical formulation for fatigue crack growth analysis is presented and the results obtained are compared with the experimental data of the Wohler curves. The critical crack configurations for which the fatigue failure occurs after a given number of loading cycles can be obtained from the above-me...
10 CitationsSource
Abstract The stress intensity factors along the crack front are calculated for straight-fronted edge cracks in bars with circular cross-section subjected to tension or bending loading. The results are deduced by means of a three-dimensional finite element analysis and the stress field singular behaviour in the vicinity of the flaw is obtained by shifting the finite element midside nodes near the crack front to quarter-point positions. Different crack depths are examined and the stress intensity ...
44 CitationsSource
— The crack propagation of a semi-elliptical surface flaw subjected to cyclic combined axial and bending loadings with constant amplitude is numerically examined according to Paris-Erdogan law. The critical crack, for which a given number of cycles is necessary to cause fatigue failure, can be determined from interaction between the theoretical results obtained and the experimental data of the Wohler curves. Some examples are presented for different stress ranges Δσt and loading eccentricities g...
13 CitationsSource
#1Jesús Toribio (Complutense University of Madrid)H-Index: 26
This paper presents the calculation of stress intensity factor (K) solutions for surface cracks in the thread ground of bolts subjected to axial loading directly applied by the nut. The stress-strain computations have been done by means of the finite element method with quarter-point singular isoparametric elements along the crack front. The stress intensity factor is calculated through the stiffness derivative method, by using a virtual crack extension technique to compute the energy release ra...
11 CitationsSource
Abstract The main macroscopic variables (in the continuum mechanics sense) which govern the microscopic fracture of notched samples of high strength steel are studied. The investigation, performed in inert and aggressive environments, offers therefore a quantitative relationship between the macroscopic and microscopic approaches to fracture, and allows a prediction of the size of the critical microstructural zone by numerical computation. The experimental programme included fracture tests on not...
33 CitationsSource
#1J Toribio (Complutense University of Madrid)H-Index: 1
#2J.M. Campos (Complutense University of Madrid)H-Index: 2
Last. V. Sanchez-Galvez (Complutense University of Madrid)H-Index: 3
view all 3 authors...
AbstractThis paper deals with the measurement of the residual stress on the thread root of an M30 bolt. The results are used in the computation of the stress intensity factor – on the cracked bolt – generated by the prior residual stresses. The optimum measurement parameters have been carefully chosen: relative position between the X-ray beam and the sample, and the irradiated spot size. The results are tensile type stresses in the bolt surface – the opposite to the few existing bibliographic da...
6 CitationsSource
Cited By2
Newest
#1Jesús Toribio (University of Salamanca)H-Index: 26
#2N. Álvarez (University of Salamanca)H-Index: 1
Last. Juan-Carlos Matos (University of Salamanca)H-Index: 11
view all 4 authors...
Abstract In this paper different stress intensity factor (SIF) solutions numerically obtained by previous researchers on transversely cracked cylinders subjected to tension loading are analyzed. Solutions are compared in the matter of stress intensity values at the centre of the crack front and at the external surface of the cylinder, and a wide range of crack aspect ratios and relative crack depths are studied, in order to provide the engineer with solutions applicable to different real situati...
50 CitationsSource
The paper gives a bibliographical review of finite element methods applied for the analysis of fastening and joining from the theoretical as well as practical points of view. The bibliography at the end of the paper contains 726 references to papers and conference proceedings on the subject that were published between 1990 and 2002. These are classified in the following categories: pin joints; thread connections; bolted joints, screws, nuts; rivets; fittings; tubular joints; expansion joints; ga...
96 CitationsSource