Effects of loading history on fatigue crack growth in high density polyethylene and toughened poly(methyl methacrylate)

1987 ◽  
Vol 27 (2) ◽  
pp. 110-115 ◽  
Author(s):  
C. B. Bucknall ◽  
P. Dumpleton
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Methyl Methacrylate ◽  
Crack Growth ◽  
High Density Polyethylene ◽  
High Density ◽  
Loading History ◽  
Poly Methyl Methacrylate

The use of crack layer theory to predict the lifetime of the fatigue crack growth of high density polyethylene

2009 ◽  
Vol 49 (7) ◽  
pp. 1421-1428 ◽  
Author(s):  
Byoung-Ho Choi ◽  
Werner Balika ◽  
Alexander Chudnovsky ◽  
Gerald Pinter ◽  
Reinhold W. Lang
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
High Density Polyethylene ◽  
High Density ◽  
Crack Layer

Assessment of Pipeline Fatigue Crack-Growth Life

2006 ◽  
Author(s):  
Carl E. Jaske
Keyword(s):  
Fatigue Crack ◽  
Cyclic Loading ◽  
Fatigue Crack Growth ◽  
Fracture Mechanics ◽  
Crack Growth ◽  
Flaw Size ◽  
Stress Intensity Factor Range ◽  
Loading History ◽  
Fatigue Crack Growth Life ◽  
Number Of Cycles

This paper describes an accepted approach for predicting fatigue crack-growth life in pipelines. Fatigue life is computed as the number of cycles for a crack-like flaw to grow from an initial size to a final critical size. This computation is performed by integrating a fracture-mechanics model for fatigue crack growth. The initial flaw size is estimated either from inspection results or by using fracture mechanics to predict the largest flaw that would have survived a hydrostatic pressure test. The final flaw size is estimated using fracture mechanics. Fracture-mechanics models for computing fatigue crack growth and predicting flaw size are reviewed. The anticipated cyclic loading must be characterized to perform the crack-growth calculations. Typically, cyclic loading histories, such as pressure cycle data, are analyzed and used to estimate future loadings. To utilize the crack-growth models, the cycles in the loading history must be counted. The rainflow cycle counting procedure is used to characterize the loading history and develop a histogram of load range versus number of cycles. This histogram is then used in the fatigue crack-growth analysis. Results of example calculations are discussed to illustrate the procedure and show the effects of periodic hydrostatic testing, threshold stress intensity factor range, and pressure ratio on predicted fatigue crack-growth life.

scholarly journals Delaying Effect of High-Density Electric Current on Fatigue Crack Growth in A6061-T6 Aluminum Alloy

2016 ◽  
Vol 57 (12) ◽  
pp. 2104-2109
Author(s):  
Jaewoong Jung ◽  
Yang Ju ◽  
Yasuyuki Morita ◽  
Yuhki Toku ◽  
Yoshihiko Uematsu
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Electric Current ◽  
Crack Growth ◽  
High Density

scholarly journals The effects of loading history on fatigue crack growth threshold.

1987 ◽  
Vol 53 (487) ◽  
pp. 428-435 ◽  
Author(s):  
Takeshi OGAWA ◽  
Keiro TOKAJI ◽  
Satoshi OCHI ◽  
Hideo KOBAYASHI
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Loading History ◽  
Growth Threshold

Loading history effect on creep-fatigue crack growth in pipe bend

2016 ◽  
Vol 139-140 ◽  
pp. 86-95 ◽  
Author(s):  
V.N. Shlyannikov ◽  
A.V. Tumanov ◽  
N.V. Boychenko ◽  
A.M. Tartygasheva
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Loading History ◽  
Pipe Bend ◽  
Creep Fatigue ◽  
History Effect ◽  
Creep Fatigue Crack

Rheological and mechanical properties of poly(α-methylstyrene-co-acrylonitrile)/ poly[(methyl acrylate-co-methyl methacrylate)] blends in miscible and phase separated regimes of various morphologies. Part IV: Influence of the morphology on the mechanical properties (IUPAC Technical Report)

2004 ◽  
Vol 76 (2) ◽  
pp. 389-413 ◽  
Author(s):  
V. Altstädt ◽  
L. Lucca de Freitas ◽  
D. W. Schubert
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Propagation ◽  
Methyl Methacrylate ◽  
Crack Growth ◽  
Methyl Acrylate ◽  
Solution Temperature ◽  
Thin Sections

Influences of the morphology on the thermal and mechanical properties of poly(α-methylstyrene-co-acrylonitrile)/poly[(methyl acrylate-co-methyl methacrylate)] (PαMSAN/PMMA) blends have been investigated. DSC measurements confirm that all blends were phase-separated due to the temperature at which they have been extruded and squeeze-molded. Based on the cloudpoints of 17 blends and TEM micrographs, the interaction parameters as a function of temperature and composition were calculated for the lower critical solution temperature (LCST) system. Varying the morphology by annealing without changing the composition of the system resulted in a finer morphology for the 85/15 blends, while the 40/60 blend showed an increase in the domain size with annealing time. Tensile strength and fracture toughness indicate that the PαMSAN domains in the tougher PMMA matrix cause a deterioration in the mechanical properties of the blends, while the PMMA domains in the PαMSAN matrix improve the mechanical properties. No clear conclusions on the influence of morphology on fracture toughness could be drawn because in one case (40/60 blend) the fracture toughness decreases slightly by annealing and in the other case (85/15 blend) fracture toughness values increase slightly with decreasing phase separation by annealing. In situ strained thin sections in the TEM indicated no effect of annealing on the micromechanical behavior. Shear deformation was observed as the prevailing deformation mechanism in the PαMSAN and fibrillized crazing in the PMMA-rich blends. From fatigue crack growth experiments it was concluded that the fatigue crack propagation threshold is higher for PMMA than for PαMSAN. Tests on the annealed samples of PαMSAN/PMMA 85/15 and 40/60 showed that the differences in morphology did not affect the fatigue crack growth resistance significantly. From the features of the fracture surface investigated by SEM, the conclusion can be drawn that the fatigue crack propagates faster in the more brittle PαMSAN phase, but the overall advance of the crack front is controlled at the interphases, resulting in a crack propagation gradient along the interphase.

Sign in / Sign up

Export Citation Format

Share Document