Investigation of the fatigue life and crack growth in torque tightened bolted joints

2011 ◽  
Vol 15 (4) ◽  
pp. 304-313 ◽  
Author(s):  
T.N. Chakherlou ◽  
M. Mirzajanzadeh ◽  
J. Vogwell ◽  
B. Abazadeh
Keyword(s):  
Fatigue Life ◽  
Crack Growth ◽  
Bolted Joints

scholarly journals Fatigue Crack Growth Analysis with Extended Finite Element for 3D Linear Elastic Material

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 397
Author(s):  
Yahya Ali Fageehi
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Crack Propagation ◽  
Crack Growth ◽  
Mixed Mode ◽  
Propagation Path ◽  
Loading Conditions ◽  
Extended Finite Element ◽  
Linear Elastic

This paper presents computational modeling of a crack growth path under mixed-mode loadings in linear elastic materials and investigates the influence of a hole on both fatigue crack propagation and fatigue life when subjected to constant amplitude loading conditions. Though the crack propagation is inevitable, the simulation specified the crack propagation path such that the critical structure domain was not exceeded. ANSYS Mechanical APDL 19.2 was introduced with the aid of a new feature in ANSYS: Smart Crack growth technology. It predicts the propagation direction and subsequent fatigue life for structural components using the extended finite element method (XFEM). The Paris law model was used to evaluate the mixed-mode fatigue life for both a modified four-point bending beam and a cracked plate with three holes under the linear elastic fracture mechanics (LEFM) assumption. Precise estimates of the stress intensity factors (SIFs), the trajectory of crack growth, and the fatigue life by an incremental crack propagation analysis were recorded. The findings of this analysis are confirmed in published works in terms of crack propagation trajectories under mixed-mode loading conditions.

Energy for crack growth in model rubber components

1972 ◽  
Vol 7 (2) ◽  
pp. 132-140 ◽  
Author(s):  
P B Lindley
Keyword(s):  
Fatigue Life ◽  
Crack Growth ◽  
Crack Surface ◽  
Uniform Stress ◽  
Numerical Techniques ◽  
Surface Displacements ◽  
Tearing Energy ◽  
Crack Growth Rates ◽  
Essential Prerequisite

The determination of tearing energy, i.e. the energy available for crack growth, is an essential prerequisite for the estimation of the fatigue life of rubber components. Three methods of determining tearing energy are considered: from changes in total energy, from crack surface displacements, and by comparison with known values for the same crack growth rates. It is shown by applying experimental and numerical techniques to plane-stress testpieces, not necessarily of uniform stress or thickness, that the methods are satisfactory.

Effects of countersunk hole geometry errors on the fatigue performance of CFRP bolted joints

2021 ◽  
pp. 095440542110285
Author(s):  
Xuda Qin ◽  
Xingfeng Cao ◽  
Hao Li ◽  
Meng Zhou ◽  
Ende Ge ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Bolted Joints ◽  
Fatigue Performance ◽  
Machining Process ◽  
Fe Model ◽  
Hole Making ◽  
Hole Geometry ◽  
Geometry Error ◽  
The Relationship ◽  
Hole Machining

Due to good aerodynamic performance and reliability, countersunk bolt joint is one of the most commonly used connection methods for carbon fiber reinforced polymer (CFRP) components in the aircraft. However, the countersunk hole machining process is inevitably accompanied by geometric errors, which will directly affect the mechanical properties of the joint structure. This paper presents a numerical and experimental investigation on the effect of countersunk hole geometry errors on the fatigue performance of CFRP bolted joints. FE model of CFRP countersunk bolted joints with designed geometry errors are established, and the rationality of the FE analysis was verified by fatigue life and failure forms. The CFRP bolted structure failure mechanism under fatigue load and influence of hole-making geometry error (including countersunk fillets radius, countersunk depth, and countersunk angle) on the fatigue life are investigated. Based on the relationship between fatigue life and the geometry error, the corresponding tolerances for CFRP bolt joint countersunk hole are determined as well. The research results can provide a reference for establishing reasonable geometric accuracy requirements for CFRP joint hole machining.

Handling Uncertainty in the Remnant Fatigue Life Assessment of Offshore Process Pipework

2016 ◽  
Author(s):  
Arvind Keprate ◽  
R. M. Chandima Ratnayake
Keyword(s):  
Fatigue Life ◽  
Crack Growth ◽  
Life Assessment ◽  
Assessment Process ◽  
Linear Elastic ◽  
Fatigue Life Assessment ◽  
Process Piping ◽  
Growth Laws ◽  
Elastic Fracture ◽  
Offshore Industry

A typical procedure for a remnant fatigue life (RFL) assessment is stated in the BS-7910 standard. The aforementioned standard provides two different methodologies for estimating RFL; these are: the S-N curve approach and the crack growth laws (i.e. using Linear Elastic Fracture Mechanics (LEFM) principles) approach. Due to its higher accuracy, the latter approach is more commonly used for RFL assessment in the offshore industry. Nevertheless, accurate prediction of RFL using the deterministic LEFM approach (stated in BS-7910) is a challenging task, as RFL prediction is afflicted with a high number of uncertainties. Furthermore, BS-7910 does not provide any recommendation in regard to handling the uncertainty in the deterministic RFL assessment process. The most common way of dealing with the aforementioned uncertainty is to employ Probabilistic Crack Growth (PCG) models for estimating the RFL. This manuscript explains the procedure for addressing the uncertainty in the RFL assessment of process piping with the help of a numerical example. The numerically obtained RFL estimate is used to demonstrate a calculation of inspection interval.

Effect of Processing Layer on Fatigue Strength of Extruded AZ61 Magnesium Alloy

2013 ◽  
Vol 577-578 ◽  
pp. 429-432 ◽  
Author(s):  
Yukio Miyashita ◽  
Kyohei Kushihata ◽  
Toshifumi Kakiuchi ◽  
Mitsuhiro Kiyohara
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Magnesium Alloy ◽  
Crack Initiation ◽  
Crack Growth ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Crack Growth Resistance ◽  
Az61 Magnesium Alloy

Fatigue Property of an Extruded AZ61 Magnesium Alloy with the Processing Layer Introduced by Machining was Investigated. Rotating Bending Fatigue Tests were Carried out with the Specimen with and without the Processing Layer. According to Results of the Fatigue Tests, Fatigue Life Significantly Increased by Introducing the Processing Layer to the Specimen Surface. Fatigue Crack Initiation and Propagation Behaviors were Observed by Replication Technique during the Fatigue Test. Fatigue Crack Initiation Life of the Specimen with the Processing Layer was Slightly Longer than that of the Specimen without the Processing Layer. Higher Fatigue Crack Growth Resistance was also Observed when the Fatigue Crack was Growing in the Processing Layer in the Specimen with the Processing Layer. the Longer Fatigue Life Observed in the Fatigue Test in the Specimen with the Processing Layer could be Mainly due to the Higher Crack Growth Resistance. it is Speculated that the Fatigue Strength can be Controlled by Change in Condition of Machining Process. it could be Effective way in Industry to Improved Fatigue Strength only by the Cutting Process without Additional Surface Treatment Process.

scholarly journals OBSERVATIONS ON FATIGUE CRACK GROWTH AND FATIGUE LIFE OF RIVETED LAP JOINTS

2012 ◽  
Vol 31 (3) ◽  
pp. 108
Author(s):  
Andrzej SKORUPA ◽  
Małgorzata SKORUPA ◽  
Tomasz MACHNIEWICZ ◽  
Andrzej KORBEL
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Lap Joints ◽  
Riveted Lap Joints
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