Crack propagation rate and failure life in biaxial low cycle fatigue at elevated temperatures

1987 ◽  
Vol 28 (5-6) ◽  
pp. 699-709 ◽  
Author(s):  
Masateru Ohnami ◽  
Masao Sakane
Keyword(s):  
Crack Propagation ◽  
Elevated Temperatures ◽  
Low Cycle Fatigue ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Cycle Fatigue ◽  
Failure Life

Crack Propagation Behavior at Sn37Pb-Copper Interface in Low Cycle Fatigue

2007 ◽  
Vol 353-358 ◽  
pp. 2962-2965
Author(s):  
Masao Sakane ◽  
Kazuhiro Itoh ◽  
Yutaka Tsukada ◽  
Kenji Terada
Keyword(s):  
Crack Propagation ◽  
Crack Path ◽  
Low Cycle Fatigue ◽  
Interfacial Crack ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Cycle Fatigue ◽  
Propagation Behavior ◽  
Integral Range ◽  
Crack Propagation Behavior

This paper studies the crack propagation at Sn37Pb-copper interface in push-pull low cycle fatigue. Bonded specimens of Sn37Pb and copper having notch holes with different distances from the interface were fatigued at 313K and the crack propagation paths were observed. Cracks propagated at the interface when the notch hole was near the interface but propagated in the solder when the notch hole was away from the interface. The propagation rate of the interfacial crack was faster than that of non-interface crack. The crack path and crack propagation rate of the two types of cracks were discussed in relation to J integral range calculated by finite element method.

scholarly journals Study of Mixed-Mode Cracking of Dovetail Root of an Aero-Engine Blade Like Structure

2019 ◽  
Vol 9 (18) ◽  
pp. 3825 ◽  
Author(s):  
Giacomo Canale ◽  
Moustafa Kinawy ◽  
Angelo Maligno ◽  
Prabhakar Sathujoda ◽  
Roberto Citarella
Keyword(s):  
Crack Propagation ◽  
Residual Life ◽  
Low Cycle Fatigue ◽  
Crack Propagation Rate ◽  
Tolerance Analysis ◽  
Propagation Rate ◽  
Design Parameters ◽  
R Ratio ◽  
Engine Industry ◽  
Aero Engine

Aerospace structures must be designed in such a way so as to be able to withstand even more flight cycles and/or increased loads. Damage tolerance analysis could be exploited more and more to study, understand, and calculate the residual life of a component when a crack occurs in service. In this paper, the authors are presenting the results of a systematic crack propagation analysis campaign performed on a compressor-blade-like structure. The point of novelty is that different blade design parameters are varied and explored in order to investigate how the crack propagation rate in low cycle fatigue (LCF, at R ratio R = 0) could be reduced. The design parameters/variables studied in this work are: (1) The length of the contact surfaces between the dovetail root and the disc and (2) their inclination angle (denoted as “flank angle” in the aero-engine industry). Effects of the friction coefficient between the disc and the blade root have also been investigated. The LCF crack propagation analyses have been performed by recalculating the stress field as a function of the crack propagation by using the FRacture ANalysis Code (Franc3D®).

Quantitative Analysis on Fatigue Fracture of Spray Formed GH738 Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 564-568 ◽  
Author(s):  
Dong Ye Yang ◽  
Wen Yong Xu ◽  
Zhou Li ◽  
Guo Qing Zhang ◽  
Zhing Liang Ning ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Crack Propagation ◽  
Fatigue Fracture ◽  
Low Cycle Fatigue ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Trapezoidal Formula ◽  
Propagation Zone ◽  
Relationship Of ◽  
The Relationship

Low-cycle fatigue (LCF) fracture of the spray formed GH738 alloy was investigated under total strain controlled mode at 650°C. Basic theory for evaluating fatigue lives by fatigue striations has been introduced. The crack length a and the crack propagation rate da/dN were measured and the curve of da/dN in crack propagation zone was obtained with Paris formula and tabulation trapezoidal formula, respectively. The size and symmetry of rapid fracture zone of fatigue were also studied. The results showed that the relationship of a and N was linear with tabulation trapezoidal formula, and the da/dN and a was conic with Paris formula. At last, quantitative analysis of fatigue fracture was also discussed.

An investigation of the roles of crack initiation, propagation and ratchetting in producing wear in metallic sliding contacts

2000 ◽  
Vol 214 (1) ◽  
pp. 63-74 ◽  
Author(s):  
J Liu ◽  
E. M. Kopalinsky ◽  
P. L. B. Oxley
Keyword(s):  
Wear Rate ◽  
Low Cycle Fatigue ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Wear Particles ◽  
Cycle Fatigue ◽  
Rotating Disc ◽  
Wear Model ◽  
Specimen Material ◽  
Frictional Forces

Experiments are described in which the edge of a hard wedge is loaded against the periphery of a rotating disc of softer specimen material. The normal and frictional forces and inward movement of the wedge as the disc wears are continually monitored throughout a test. The results obtained are used together with measurements of the wearing surfaces of metallographic sections to test a newly proposed wear model. In this model it is assumed that ratchetting causes failure of the surface and hence the production of wear particles, while low-cycle fatigue determines the crack propagation rate and hence the wear rate.

scholarly journals Mode I Crack Propagation Experimental Analysis of Adhesive Bonded Joints Comprising Glass Fibre Composite Material under Impact and Constant Amplitude Fatigue Loading

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4380
Author(s):  
Alirio Andres Bautista Villamil ◽  
Juan Pablo Casas Rodriguez ◽  
Alicia Porras Holguin ◽  
Maribel Silva Barrera
Keyword(s):  
Crack Propagation ◽  
Structural Integrity ◽  
Crack Propagation Rate ◽  
Fatigue Loading ◽  
Propagation Rate ◽  
Operating Conditions ◽  
Impact Testing ◽  
Mode I ◽  
Mode I Crack ◽  
Constant Amplitude

The T-90 Calima is a low-wing monoplane aircraft. Its structure is mainly composed of different components of composite materials, which are mainly bonded by using adhesive joints of different thicknesses. The T-90 Calima is a trainer aircraft; thus, adverse operating conditions such as hard landings, which cause impact loads, may affect the structural integrity of aircrafts. As a result, in this study, the mode I crack propagation rate of a typical adhesive joint of the aircraft is estimated under impact and constant amplitude fatigue loading. To this end, effects of adhesive thickness on the mechanical performance of the joint under quasistatic loading conditions, impact and constant amplitude fatigue in double cantilever beam (DCB) specimens are experimentally investigated. Cyclic impact is induced using a drop-weight impact testing machine to obtain the crack propagation rate (da/dN) as a function of the maximum strain energy release rate (GImax) diagram; likewise, this diagram is also obtained under constant amplitude fatigue, and both diagrams are compared to determine the effect of each type of loading on the structural integrity of the joint. Results reveal that the crack propagation rate under impact fatigue is three orders of magnitude greater than that under constant amplitude fatigue.

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