bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatitis B virus‐associated glomerulonephritis in adults
Authors: LAI KAR NENG
Published: April 2007

Summary: There is strong evidence that chronic hepatitis B virus (HBV) infection is associated with the development of glomerulonephritis (GN). Membranous nephropathy, mesangiocapillary nephropathy and mesangial proliferative glomerulonephritis (with IgA deposits) are the best documented HBV‐associated GN. Our findings indicate the presence of viral transcription in glomerular cells and renal tubular epithelia supporting an aetiological role of HBV in some chronic HBV carriers who develop co‐existing glomerulonephritis. Although the natural history of these glomerulonephritides is now better known, complete cure may not always be possible. Prevention by vaccinating newborns with HBV vaccine should be practised in endemic areas. Alfa‐interferon therapy should be tried in HBV‐associated glomerulonephritis in children or adult with short duration of infection.
Nephron endowment at birth and the pathogenesis of hypertension and chronic renal failure
Authors: MACKENZIE HARALD S , LAWLER ELIZABETH V , BRENNER BARRY M
Published: April 2007

Summary: It is well established that extensive ablation of renal mass initiates a cycle of accelerated, progressive glomerular injury in remnant kidneys. This process is associated with extreme nephron hypertrophy and hyperfiltration and systemic hypertension. Severe congenital deficiencies in nephron number are also associated with adverse effects on the kidney. In rodents, more subtle reductions in nephron supply are known to advance age‐related glomerular injury. Since intra‐uterine growth retardation is associated with formation of fewer nephrons, the recent observation that low birthweight is associated with increased risk of hypertension in later life raises the possibility that comparatively modest reductions in nephron complement may predispose to hypertension and renal injury over 4–5 decades. the finding of an association between short stature, a marker of low birthweight and nephropathy among type I diabetics also implies that a modest congenital nephron underendowment predisposes to glomerular injury. the numbers of viable nephrons supplied to renal allograft recipients may be critical determinants of late allograft success or failure, since unique circumstances combine to lower the nephron complement to levels akin to those seen in patients with surgical reduction of a solitary kidney, in whom predisposition to hypertension and glomerulosclerosis is evident. This article summarizes recent findings that suggest that congenital nephron endowment is a significant and overlooked factor in the pathogenesis of chronic renal disease and hypertension.
Comments on adequacy, nutrition and survival with peritoneal dialysis and haemodialysis
Authors: NOLPH KARL D
Published: April 2007

Summary: This paper summarizes the status of the worldwide peritoneal dialysis population at the end of 1994. Relative mortality risks on peritoneal dialysis and haemodialysis are compared. Clearance targets for continuous ambulatory peritoneal dialysis are discussed.
Morphometric insights into nephrotic syndrome in children: Are we any wiser?
Authors: DANILEWICZ Marian , WAGROWSKA‐DANILEWICZ Malgorzata
Published: April 2007

Summary: The present study was undertaken in the hope that conflicting opinions concerning interrelationships among minimal change disease (MCD), mesangial proliferative glomerulonephritis (MPG) and focal segmental glomeruloscierosis (FSGS) might be elucidated by morphometric methods performed by image analysis, as well as to study whether serum creatinine and changes in quantitatively analysed glomeruli could correlate with the interstitial fibrosis in these glomerulopathies. Fifteen renal biopsy specimens from children with MCD, 10 with primary MPG and 12 with FSGS for whom both light and electron microscopy as well as immunofluorescence microscopy and full clinical data were available, were examined quantitatively. As a control five biopsy and 10 autopsy specimens of the normal kidneys were used. Our quantitative study showed that in MCD, MPG and FSGS glomerular and interstitial values differed from normal. Morphometric differences between MPG and both MCD and FSGS groups were also shown. Although the mean values of total glomerular area and relative interstitial volume were increased in FSGS patients, in total glomerular cells per unit of glomerular area and mesangium (% of total glomerular area) were similar in both MCD and FSGS groups. In MPG strong positive correlations existed between interstitial volume and serum creatinine, interstitial volume and total glomerular cells per unit of glomerular area as well as between interstitial volume and glomerular mesangium (% of total glomerular area). In FSGS there was significant positive correlation between interstitial volume and serum creatinine. In the MCD group all correlations were weak and not significant. In conclusion, our morphometric studies suggest a close relationship between MCD and FSGS, and indicate that MPG is a separate morphologic entity in children.
Do macrophages participate in mesangial cell proliferation?
Authors: TESCH Gregory H , NIKOLIC‐PATERSON David J , LAN Hui Y
Published: April 2007

Summary: Mesangial cell proliferation is a harbinger of glomerulosclerosis, leading to end‐stage renal failure. It is, therefore, important to identify the factors that promote mesangial cell proliferation in order gain a better understanding of the progression of glomerular disease. A number of human and animal studies of glomerulonephritis have shown that infiltrating macrophages are prominent within mesangial proliferative lesions, suggesting that macrophages participate directly in the mesangial proliferative response. In vitro studies support a role for macrophages in mesangial cell proliferation. Macrophage interaction with mesangial cells through the action of leuckocyte adhesion molecules facilitates mesangial cell proliferation. This may be mediated by macrophage production of a number of mesangial cell growth factors or by modulating the mesangial matrix to promote mesangial cell growth. Mesangial cells may play an active role in this process, since mesangial cell production of chemoattractant molecules may be a key event in inducing macrophage recruitment into the injured mesangium. Taken together, these data suggest that macrophages and mesangial cells work in a co‐operative fashion in the development of mesangioproliferative disease.
Renin‐angiotensin system component gene polymorphisms in Japanese maintenance haemodialysis patients
Authors: KAWADA Noritaka , MORIYAMA Toshiki , YOKOYAMA Kenji , YAMAUCHI Atsushi , ANDO Akio , MIKAMI Hiroshi , FUJII Masamitu , KAJIMOTO Yoshiteru , HORIO Masaru , IMAI Enyu
Published: April 2007

Summary: The renin‐angiotension system (RAS) component gene polymorphisms was examined in 216 patients undergoing maintenance haemodialysis (HD) therapy and in 208 control subjects. the RAS polymorphisms selected for analysis were angiotensin I converting enzyme (ACE) I/D, angiotensinogen (Agt) T235/M235, angiotensin II type 1 receptor (AGT1R) A1166/C1166. the control allelic frequencies was ACE I/D (0.63/0.37), Agt T235/M235 (0.16/0.84), and AGT1R A1166/C1166 (0.94/0.06). Recently, relationships between ACE I/D and the progression of renal disease attract great attention in Japanese and Caucasian populations. ACE D allele was expected to be more frequent in HD population. However, no accumulation of ACE D allele or Agt T235 allele, AFT1R C1166 allele in Japanese end‐stage renal disease (ESRD) subjects was detected. to explain the paradoxical result of positive association of ACE D allele with progression of renal disease and no bias of ACE genotype in ESRD subjects, further investigation with systematic prospective study regarding the change of ACE genotype distribution around the period of entering dialysis therapy is required.
Effect of supplementation with antioxidants (α‐tocopherol and ascorbic acid) on markers of renal tubular injury in cardiac surgery patients
Authors: WESTHUYZEN Justin , COCHRANE Andrew D , TESAR Peter J , MAU Terrence , FLEMING Simon J
Published: April 2007

Summary: Cardiac surgery is accompanied by the risk of ischaemia‐reperfusion injury to both myocardial and peripheral tissues like the kidney due to the generation of oxygen‐derived free radicals. Supplementation with chain‐breaking antioxidants may trap free radicals and help protect tissues from injury. We therefore examined the effect of pre‐treating cardiac surgery patients with α‐tocopherol (vitamin E) and ascorbic acid (vitamin C) or placebo on a hypoxia‐sensitive tissue, the renal proximal tubule. Sixty‐nine subjects undergoing elective coronary artery bypass grafting participated in a prospective, double‐blind, placebo controlled randomized trail, receiving either placebo or both 750 IU/dL‐α‐tocopherol per day for 7‐10 days, and 1 g ascorbic acid 12 h prior to surgery. Plasma α‐tocopherol concentrations fell from elevated to normal levels in the supplemented group and from normal to negligible levels in the placebo group. Renal tubular markers (N‐acetyl‐β‐D‐glucosaminidase, adenosine deaminase binding protein, and γ‐glutamyl transpeptidase) increased significantly relative to creatinine in both groups following surgery (P > 0.001). However, there were no differences between the two patient groups. Thus, although antioxidant supplementation prior to cardiac surgery prevented the depletion of the primary lipid‐soluble antioxidant in plasma (α‐tocopherol), renal tubular injury was not measurably reduced.
1996 Hong Kong Renal Registry Report
Authors: Lui SF
Published: April 2007

Summary: This report was based on the data from the Renal Registry of the Hospital Authority of Hong Kong and accounted for approximately 90‐95% of all the patients on Renal replacement therapy (RRT) in Hong Kong. Patients receiving treatment under the private sectors were not included in this report. the data were as of 31 December 1996. There were 15 renal units (2.4 unit per million population [pmp]) and four major renal transplant centres. the number of patients on RRT was 3337 (530 pmp), of which 56% (299 pmp) were on peritoneal dialysis (PD), 15% (79 pmp) on haemodialysis (HD) and 29% (152 pmp) with functioning kidney transplants (TX). the net increase in the number of patients on RRT was +12% from the previous year. the incidence of end stage renal failure was 640 (102 pmp). the median age of patients on RRT was 49 years, of which 27% were above the age of 61 years. For new patients who commenced on RRT during 1996, the median age was 56 years, of which 36% were above the age of 61 years. the causes of renal failure were glomerulonephritis 37%, unknown 30%, diabetes 13%, inherited and congenital 5%, infection/reflux 3%, hypertensive/renal vascular disease 3%, urolithiasis 2%, obstructive 1% and others 5%. For new patients entered into the programme during 1996, 25% were due to diabetic nephropathy. Ten per cent of all the patients on RRT were serologically positive for hepatitis B infection (PD 12%, HD 6%, TX 9%). 5% of all the patients on RRT were positive for hepatitis C infection (PD 3%, HD 12%, TX 7%). Seventy‐nine per cent of all the patients on dialysis were on PD (1885 patients, 299 pmp), of which 96% were on CAPD. Thirty‐eight per cent of the patients on CAPD were on straight‐line systems, 35% on disconnecting systems and 20% on UV flash systems. Four‐hundred and ninety‐five patients (79 pmp) were on HD, of which 59% were on hospital based HD, 15% on satellite centre based HD, 10% on charitable centre based HD and 5% on home HD. Nine‐hundred and fifty‐seven patients (152 pmp) had a functioning kidney graft. 542 (57%) were transplanted in Hong Kong, of which 50% were cadaveric kidney transplantations. During 1996, 121 patients (19 pmp) received a kidney transplantation. Eighty‐four transplants were performed in Hong Kong, of which 58 were with cadaveric kidneys and 26 with living related kidneys. the annual mortality rate for all RRT was 7.3% (10% for PD, 8% for HD and 1% with TX). the major causes of death were infection (28%), cardiovascular (26%) and cerebral vascular accident (9%). Outcome indicators were on patients entered into the RRT programme during 1995, thus allowing for 1 year of follow up. For CAPD as the first RRT, 1 year patient and technique survival (censored for death and non‐technique failure) were 94% and 93%. For living related kidney transplants performed in Hong Kong, 1 year patient and graft survival (censored for death) were both 100%. For cadaveric kidney transplants, 1 year patient and graft survival were 98% and 96%
Intercellular adhesion molecule‐1 and tumour necrosis factor‐α expression in human glomerulonephritis
Authors: MA Lijun , YANG Bin , NIKOLIC‐PATERSON David J , CHEN Yipu , ATKINS Robert C , WANG Haiyan
Published: April 2007

Summary: The relationship between renal expression of intercellular adhesion molecule‐1 (ICAM‐1), glomerular hypercellularity, renal function and renal tumour necrosis factor‐α (TNF‐α) expression was examined by immunohistochemistry staining in 64 cases of human glomerulonephritis. Glomerular anti‐ICAM‐1 antibody staining was increased in most cases of IgA nephropathy and lupus nephritis, but was unchanged compared to normal in membranous nephropathy and minimal change disease, and reduced in glomerular sclerosis. However, when taken together, patients with mild or no glomerular hypercellularity (group A) showed normal ICAM‐1 expression, those with moderate to severe hypercellularity (group B) had increased glomerular ICAM‐1 expression (P<0.001), while those with glomerular sclerosis (group C) had reduced glomerular ICAM‐1 expression. Patients in groups B and C also showed a significant increase in tubular ICAM‐1 expression (P<0.01) and interstitial infiltration of ICAM‐1 + cells (P<0.001). Indeed, tubular ICAM‐1 expression correlated with decreased creatinine clearance (r= ‐0.352; P<0.05). In situ hybridization demonstrated that increase in tubular ICAM‐1 staining was due to de novo gene expression, rather than absorption of soluble ICAM‐1 from the lumen. Focal expression of tumour necrosis factor‐α was seen in areas of leucocyte infiltration and strong ICAM‐1 expression. Indeed, TNF‐α staining correlated with increased renal ICAM‐1 expression in both glomerular and tubulointerstitial compartments (r=0.81; P<0.01). to confirm that TNF‐α can directly stimulate renal ICAM‐1 expression, TNF‐α was shown to transiently increase ICAM‐1 mRNA synthesis for 4‐8 h and cause a progressive increase in ICAM‐1 protein on the surface of cultured human mesangial cells. In summary; (i) increased glomerular ICAM‐1 expression was restricted to cases of moderate to severe hypercellularity; (ii) tubular ICAM‐1 expression correlated with both creatinine clearance and interstitial infiltration of ICAM‐1+ cells; and (iii) TNF‐α expression was shown to correlate with the degree of renal ICAM‐1 expression, suggesting that local TNF‐α plays an important role in the up‐regulation of ICAM‐1 in human glomerulonephritis.
Fibrillary glomerulonephritis in a patient with familial sensorneural deafness
Authors: ICHIKAWA Haruo , IKEDA Shuji , HASHIMOTO Masami , NAGAKE Yoshio , HIRONAKA Kazue , SHIKATA Kenichi , MAKINO Hirofumi
Published: April 2007

Summary: A 47‐year‐old woman was admitted to the hospital for evaluation of proteinuria. Bilateral sensorineural deafness had been diagnosed previously at age 35. She had a positive family history of deafness going back three generations. A renal biopsy showed the presence of highly organized fibrillary deposits in the subendothelial mesangial areas. the microfibrils had a diameter of 11‐16 nm, larger than the diameter of amyloid fibrils, and did not have a microtubular appearance. the renal specimen was negative for Congored staining. There was no clinical or serologic evidence of paraproteinaemia, cryoglobulinaemia, light‐chain disease, or systemic lupus erythematosus. the diagnosis was fibrillary glomerulonephritis. This is the first known case of fibrillary glomerulonephritis in a patient with familial sensorineural deafness.
Involvement of MAP kinase phosphatase‐1 in mesangial cell growth regulation
Authors: MORIYAMA Toshiki , XIA Chen , MIYAI Akiko , AKAGI Yoshitaka , ISAKA Yoshitaka , KANEKO Tetsuya , KAWADA Noritaka , UEDA Naohiko , YAMAUCHI Atsushi , HORIO Masaru , ANDO Akio , IMAI Enyu , HORI Masatsugu
Published: April 2007

Summary: Mitogen‐activated protein (MAP) kinase phosphatase‐1 (MKP‐1) is encoded by the mitogen‐inducible gene 3CH 134. MKP‐1 has recently been shown to be a dual specificity (serine/threonine, tyrosine) protein phosphatase, which dephosphorylates and inactivates MAP kinases in vitro and in vivo. to seek the role of MKP‐1 in growth regulation of mesangial cells, expression of MKP‐1 mRNA in cultured mesangial cells and in glomeruli isolated from anti‐Thy 1.1 mesangial proliferative glomerulonephritis rats was studied. the effect of inhibition of endogenous MKP‐1 by use of antisense‐DNA technology on the regulation of MAP kinase activity and the growth regulation of rat cultured inesangial cells was also studied. By northern blot analysis, it was demonstrated that in mesangial cells, MKP‐1 mRNA expression was rapidly induced after the stimulation by serum, growth factors and vasoactive peptides. Maximal signals were found in 30‐60 min in all growth factors tested. Fetal calf serum (FCS) was the most potent stimulus of MKP‐1 mRNA expression, followed by platelet‐derived growth factor (PDGF)‐B and arginine vasopressin. to elucidate a possible involvement of MKP‐1 in disease development of mesangial proliferative glomerulonephritis, MKP‐1 mRNA expression was examined in rat anti‐Thy 1.1 glomerulonephritis model. A marked increase in MKP‐1 mRNA level in isolated glomeruli was observed at day 3 after disease induction (4.3‐fold over control). In situ hybridization of MKP‐1 mRNA in Thy 1.1 glomerulonephritius rats confirmed the enhanced glomerular expression of MKP‐1. to study the role of MKP‐1 in mesangial cell growth regulation, phosphorothioate oligodeoxynucleotide (ODN) were used to modulate MKP‐1 expression. an antisense ODN targeting the translation initiation site of MKP‐1 mRNA inhibited stimulated (by FCS, or PDGF‐B) DNA synthesis and FCS‐ or PDGF‐induced mitogenesis in mesangial cells. Sense ODN or mismatched ODN had no effect on the DNA synthesis or mitogenic response of mesangial cells. These results suggest that MKP‐1 is an immediately early gene in rat mesangial cells and it plays a critical role in growth regulation of mesangial cells in vitro.
A clinicopathological study of adult Japanese IgA nephropathy patients: Early stage cases and cases with exacerbation
Authors: SHIMADA Hisaki , IMAI Naofumi , MIYAKAWA Yoshikazu , NAKAMARU Tukasa , KARASAWA Ryo , OSAWA Yutaka , UENO Mitsuhiro , NISHI Shinichi , SUZUKI Yasushi , ARAKAWA Masaaki
Published: April 2007

Summary: Most cases of adult type IgA nephropathy (IgAN) have an insidious onset and asymptomatic course. However, some patients reveal recurrent macroscopic haematuria following episodes of respiratory or urinary tract infections. In order to clarify the correlation between clinical features and histological alterations or prognosis, 42 cases of early stage IgAN and 40 cases with acute exacerbation episodes were investigated and compared with a control group. Early stage cases were defined as having had a renal biopsy within 1 year after the first detection of urinary abnormalities, and had normal urinary findings within the 12 months before the first detection of urinary abnormalities. Acute exacerbation cases were defined as macroscopic haematuria or worsening of urinary abnormalities after acute infectious episodes and undergoing a renal biopsy within 120 days after the onset of these episodes. the early stage cases had better renal function and lower systolic and diastolic blood pressure than that of control group. They also showed milder changes in mesangial cell proliferation, mesangial matrix increase, totally sclerotic glomeruli, and tubulo‐interstitial changes. However, it is important to note that glomerular and interstitial sclerotic changes were observed even in early stage cases. Endothelial detachment was noticed more frequently in the early stage cases. Acute exacerbation cases revealed lesions of endocapillary proliferation, mesangiolysis and endothelial detachment more frequently, although these changes were segmental in each glomerulus. There was no statistical difference in disease prognosis between cases with and without acute exacerbation. These data indicated that there are characteristic histological changes in early stage cases and acute exacerbation cases of IgAN.
A D.C. POTENTIAL DROP METHOD TO MONITOR CRACK GROWTH IN NOTCHES SUBJECTED TO TORSION
Authors: HAY E. , BROWN M. W.
Published: April 2007

Abstract—

A d.c. potential drop formula has been established for monitoring crack growth in circular notched members subjected to torsion. Changes in crack depth of 20 μm can be detected in cracks growing up to 2 mm in depth.
STRESS INTENSITY AND FATIGUE CRACK GROWTH IN MULTIPLY‐CRACKED, PRESSURIZED, PARTIALLY AUTOFRETTAGED THICK CYLINDERS*
Authors: PARKER A. P.
Published: April 2007

Stress intensity factors are determined for internally and externally cracked, pressurized thick cylinders with partial autofrettage (less than 100% overstrain). The solutions are based on a superposition of existing solutions which does not involve any loss of accuracy. Implications of the stress intensity factor results for the safe‐life design of pressure vessels subjected to fatigue are discussed.
FATIGUE LIFE BEHAVIOR OF COPPER SINGLE CRYSTALS. PART II: MODEL FOR CRACK NUCLEATION IN PERSISTENT SLIP BANDS
Authors: CHENG ALEX S. , LAIRD CAMPBELL
Published: April 2007

A crack nucleation model is constructed based on the random slip of the dislocations within the fatal persistent slip band (PSB). From such a model, we derive the notch‐peak probability function. The crack is considered to nucleate when a critical notch depth is attained. This depth is constant for applied strains corresponding to the plateau of the cyclic stress‐ strain curve because the stress is constant. The PSBs behave in such a way that the more concentrated their localized slip the fewer the cycles required to attain the critical notch depth. Using the experimental relation between the applied strain and the magnitude of the slip offsets (reported in Part I) in conjunction with observations of the notch distributions along the gage surface, we have obtained the relation between the applied strain and the cycles for crack nucleation. A log‐log plot of this relation shows a slightly different slope from that of the Coffin‐Manson life data, previously reported. However, by allowing for cycles spent in Stage II propagation, good agreement is obtained.
MIXED‐MODE FATIGUE THRESHOLDS
Authors: HUA GAO , BROWN M. W. , MILLER K. J.
Published: April 2007

Abstract— Near threshold fatigue crack growth under mixed‐mode loading and elastic plane‐strain conditions has been studied in 316 stainless steel in laboratory air at room temperature. Particular emphasis was placed on the influence of the mode II component. Crack growth from the starter crack, although initially coplanar, branches to be perpendicular to the maximum normal stress. However the threshold for the branched crack growth is controlled not only by mode I displacement, but also by the mode II component. Upper and lower bound curves are obtained for the threshold condition and discussed in terms of crack tip reversed plastic deformation, crack surface rubbing and oxide‐induced closure. A theoretical method for predicting the lower bound curve is proposed and compared with the maximum normal stress and strain energy density criteria. The new theory shows the best agreement with experimental results, giving a safe prediction for design purposes.
FATIGUE CRACK PROPAGATION IN A CAST MAGNESIUM ALLOY
Authors: Chuan‐Yao Chen , Da‐Xing Gao
Published: April 2007

Abstract—Fatigue crack propagation behaviour in a cast Mg‐Al‐Zn alloy was examined. The fatigue crack growth rate of the alloy under constant amplitude loading and the threshold resulting from a number of tests are given. Delayed retardation after the application of a single tension overload is explored in detail and described by using the model proposed by Matsuoka and Tanaka. From these observations, it may be seen that the Matsuoka model can be applied to the cast magnesium alloy as well as steels and aluminium alloys. Changes in the extent of retadation and the overload affected zone size with respect to the ratio of peak‐to‐baseline stress intensity factor range are discussed. Two phenomena, delayed arrest and acceleration in the later stages of retardation are reported.
ESTIMATING INITIATION TIMES OF SECONDARY FATIGUE CRACKS IN DAMAGE TOLERANCE ANALYSIS
Authors: Brussat T. R.
Published: April 2007

Abstract—Fatigue cracking of complex structure often involves several interacting cracks developing in a sequence of crack growth, arrest and reinitiation. A “combined” method of damage tolerance analysis is presented which employs fracture mechanics concepts to calculate crack growth and fatigue data from notched coupons with the appropriate notch radius for the crack initiation phase. The notched coupon data, plotted as peak elastic notch stress vs cycles to crack initiation, are shown to be applicable even when limited yielding occurs at the notch root. For several practical reasons it is recommended to select the initial crack size,ai, for the crack growth phase to be as large as possible, but in accord with two selection criteria. First,ai, must be within a notch‐root region wherein the elastic stress distributions near a variety of notches are virtually identical. Secondly,aimust be small enough not to significantly influence the stress distributions for other cracks. The Combined Method is illustrated by means of an example involving fatigue crack growth along a widthwise row of holes in 305 mm wide test panels.
PROPAGATION AND NON‐PROPAGATION OF SHORT FATIGUE CRACKS AT A SHARP NOTCH
Authors: Tanaka K. , Nakai Y.
Published: April 2007

Abstract— Sharply notched specimens of a structural low‐carbon steel were fatigued under several ratios of the maximum to minimum loads. The growth behavior of a short fatigue crack near the notch tip was analyzed based on crack closure measurements. A fatigue crack first decelerates with increasing crack length, and then accelerates or becomes non‐propagating depending on the applied stress. A similar deceleration is seen when the rate is correlated to the stress intensity range. The effective stress intensity range is a unique parameter in correlating the growth rate of a short crack for all the stress levels examined, and the relation is identical to that obtained for a long crack. By considering the increase in crack closure with crack length, a quantitative method is proposed for predicting the non‐propagating crack length and the fatigue limit of notched specimens as a function of the applied stress and the notch geometry.
SLOW FATIGUE CRACK GROWTH AND THRESHOLD BEHAVIOUR IN IMI 685
Authors: HICKS M. A. , JEAL R. H. , BEEVERS C. J.
Published: April 2007

Abstract— Fatigue thresholds and crack growth rates up to 10−4 mm cycle −1 have been measured in β processed IMI 685. The results obtained in laboratory air for material having an aligned α microstructure and a random basketweave microstructure displayed a pronounced load ratio dependence which increased with decreasing ΔK. This sensitivity to mean load was also apparent from the threshold results determined in a vacuum of 5 ± 10−6 torr.

Fractographic observations, compliance measurements, pd output and crack path replication have indicated that contacts can be made between the fracture faces at a number of points behind the crack tip during the load cycle. These contacts wedge the crack open, thus preventing the stress intensity from falling to the value associated with the minimum applied load. A critical stress intensity, Kop, has been determined which relates to the crack being fully “open” and the results are reanalysed and discussed in terms of an effective stress intensity range, ΔKeff.
FATIGUE STRENGTH OF 7075‐T6 ALUMINIUM ALLOY UNDER COMBINED AXIAL LOADING AND TORSION
Authors: Tanaka, K. , Matsuoka S. , Kimura M.
Published: April 2007

The fatigue strength of 7075‐T6 aluminium alloy under combined axial loading and torsion was examined. The S‐N relations were correlated with the von Mises criterion for the high cycle region (Nf≥ 104 cycles) and with the Tresca criterion for the low cycle region (Nf < 104 cycles), where Nf is the cycles to failure. This transition at Nr= 104 cycles was related to the occurrence of macroscopic plastic straining and a change in fracture modes. The results are discussed in comparison with those for a high strength steel (SNCM8) in a previous study. Particular attention is given to differences in cyclic deformation behaviour, fracture modes and fatigue crack growth rates between the two materials.
EFFECT OF PROCESSING ON THE HIGH TEMPERATURE LOW CYCLE FATIGUE PROPERTIES OF MODIFIED 9Cr‐1Mo FERRITIC STEEL
Authors: Ebi G. , McEvily A. J.
Published: April 2007

The high temperature low cycle fatigue properties of modified 9Cr‐1Mo ferritic steel in a hot forged and a hot rolled condition have been evaluated. The hot forged material exhibited inferior fatigue properties as compared to the finer grained hot rolled material. Analysis of the data indicates that a larger grain size adversely affects the initiation stage but has little effect on the propagation stage. A steeper slope on the Coffin‐Manson plot results when the number of cycles to initiation is reduced.
FATIGUE BEHAVIOR OF A RAIL STEEL
Authors: Scutti J. J. , Pelloux R. M. , Fuquen‐Moleno R.
Published: April 2007

The fatigue behavior of a hot‐rolled, control‐cooled, plain carbon eutectoid rail steel has been characterized. The data include monotonic and cyclic stress‐strain curves, low cycle fatigue data and near‐threshold fatigue crack growth rate behavior in air and in vacuo. The effects of environment and mean stress on the near‐threshold fatigue crack growth rates of rail steel are significant. At a low stress ratio (R), ΔKo is lower in vacuum (7 MPa √m) than in moist air (10 MPa √m). At high R, ΔKo is higher in vacuum (6 MPa √m) than in air (4 MPa √m). The beneficial effect of moist air on FCGR at low ΔK and low R is attributed to an increase in closure due to fracture surface roughness and oxide film.
SHEAR FATIGUE CRACK GROWTH: A LITERATURE SURVEY
Authors: Liu H. W.
Published: April 2007

A fatigue crack is often initiated by a localized cyclic plastic deformation in a crystal where the active slip plane coincides with the plane of maximum shear stress. Once a crack is initiated, the crack will propagate on the maximum shear plane for a while and, in the majority of the cases, will eventually change to the plane of the applied tensile stress. The “shear” and “tensile” modes of fatigue crack propagation are termed stage I and stage II fatigue crack growth. They are also known as mode II and mode I fatigue crack growth. However, the mechanism of the tensile mode fatigue crack propagation is shear in nature.

Considerable progress has been made recently in the understanding of mode II fatigue crack growth. This paper reviews the various test methods and related data analyses.

The combined mode I and mode II elastic crack tip stress field is reviewed. The development and the design of the compact shear specimen are described and the results of fatigue crack growth tests using the compact shear specimens are reviewed. The fatigue crack growth tests and the results of inclined cracks in tensile panels, center cracks in plates under biaxial loading, cracked beam specimens with combined bending and shear loading, center cracked panels and the double edge cracked plates under cyclic shear loading are reviewed and analyzed in detail.
AN EGF EXERCISE IN PREDICTING DUCTILE INSTABILITY: PHASE 1, COMPACT TENSION SPECIMENS
Authors: Milne I.
Published: April 2007

The results of a round robin exercise in predicting ductile instability in two compact tension test specimens are presented and analysed. Many techniques were used, both to analyse the given raw data and to analyse the specimen behaviour, and large differences were obtained especially in defining J‐resistance parameters. Despite these differences there was little scatter in the final result principally because the specimens failed at plastic collapse. It was concluded that all the techniques were broadly satisfactory provided a plastic collapse analysis is performed, either as part of the analysis or independently.
PREDICTION AND EVALUATION OF LONG‐TERM CREEP‐FATIGUE LIFE
Authors: Yamaguchi Koji , Nishijima Satoshi
Published: April 2007

Ordinary short‐term creep fatigue tests were carried out on a servo‐hydraulic testing machine for various heat resistant steels. From these results a life prediction method in the long‐term creep‐fatigue regime is proposed using creep rupture ductility data up to 105 h. To verify the predicted life the authors have developed a new type of testing machine driven by thermo‐actuator which can evaluate the long‐term creep‐fatigue behaviour of materials beyond 104 h.
A NEW METHOD TO PREDICT THE LIFE UNDER HIGH‐TEMPERATURE LOW CYCLE FATIGUE CONDITIONS
Authors: Danzer R. , Bressers J.
Published: April 2007

The low cycle fatigue lives of some nickel‐base alloys tested at high temperature are predicted using a linear time dependent damage accumulation rule. Based on stress rupture data, the rule correctly predicts the cyclic life provided that the ratio of the inelastic strain rate in the cycle to the minimum creep rate in a stress rupture test (performed at the maximum cycle stress and at the same temperature) is near to one. If this ratio is much larger than one, the rule gives an upper limit to the cyclic life time. For that case a modified rule is proposed with a single fitting parameter which is adjusted to high frequency low‐cycle fatigue test data. Using the nickel‐base alloy data it is shown that life extrapolations to (i) low testing frequencies, (ii) a higher temperature and (iii) different cycle shapes, are possible too within a factor of two.
ANALYSIS OF FATIGUE CRACK PROPAGATION UNDER BIAXIAL LOADING USING AN INCLINED STRIP YIELD ZONE MODEL OF CRACK TIP PLASTICITY
Authors: Ahmad J. , Leis B. N. , Kanninen M. F.
Published: April 2007

The work reported in this paper is based upon an inclined strip yield zone model of crack tip plasticity under biaxial remote loading. Equations are developed to predict fatigue crack growth rate under steady state conditions. A qualitative agreement between model predictions and experimental data is shown.
ON DIMENSIONAL ANALYSIS OF FATIGUE CRACK GROWTH RATE AND GEOMETRICAL SIMILITUDE OF CRACKS
Authors: Navarro A. , Rios E. R. de los
Published: April 2007

Dimensional analysis has been applied to the fatigue failure of a material. The growth rate of cracks propagating within the limitations of LEFM can be described unequivocably by ΔK, as for example, in the Paris law. However, in the more general case, when LEFM conditions are violated or when the crack is short, an extra term, relating plastic zone size to crack length, is needed to preserve the physical similarity.
OVERLOAD RETARDATION IN A STRUCTURAL STEEL
Authors: Shin C. S. , Fleck N. A.
Published: April 2007

The mechanisms causing crack growth retardation after an overload were examined for BS4360 50B steel. It was found that plasticity‐induced crack closure is the main cause of retardation when the pre‐overload growth rate is in the mid‐regime of the growth rate versus stress intensity range plot. When the pre‐overload growth rate is near threshold it is argued that retardation at the surface of the specimen is primarily due to strain hardening and to the build‐up of a favourable residual stress distribution in the material ahead of the crack tip. Supporting evidence for this argument is provided by a preliminary test on 2014A‐T4 aluminium alloy. Plasticity‐induced crack closure may be a further cause of retardation in the bulk, plane strain regions of the specimens made from BS4360 50B steel and 2014A‐T4 aluminium alloy, when the pre‐overload growth rate is near threshold.
LIFE PREDICTION OF 316 STAINLESS STEEL UNDER CREEP‐FATIGUE LOADING
Authors: Yagi K. , Kanemaru O. , Kubo K. , Tanaka C.
Published: April 2007

Life prediction for creep‐fatigue loading conditions should be related to creep damage mechanisms. In order to examine the effect of the creep damage mode on rupture life under creep‐fatigue loading, a “combined creep‐fatigue loading test” was carried out on 316 stainless steel. In this method, creep loading and fatigue loading are repeated alternately. The fracture criteria under combined loading closely depend on the creep fracture modes of the static creep test. A new life prediction method which uses this new fracture criterion is proposed. The criteria are changed when the creep damage mode varies. In order to verify the adequacy of this method, fatigue tests with a tensile strain‐hold wave form were carried out. It is clear that rupture life in such fatigue tests is dependent on the chosen fracture criteria.
PREDICTION OF THE LENGTH OF NON‐PROPAGATING FATIGUE CRACKS
Authors: Yates J. R. , Brown M. W.
Published: April 2007

Abstract— Non‐propagating cracks have been observed at notch roots by several workers. A simple linear elastic fracture mechanics model based on the Kitagawa‐Takahashi diagram is presented in this paper to predict the occurrence and length of non‐propagating cracks. Predicted crack lengths are compared with experimental data taken from the literature.
RAIN FLOW CYCLE DISTRIBUTIONS FOR FATIGUE LIFE PREDICTION UNDER GAUSSIAN LOAD PROCESSES
Authors: Lindgren G. , Rychlik I.
Published: April 2007

Abstract— We present a new and simple definition of the Rain Flow Cycle count method for the analysis of a random load process. It is combined with the Palmgren‐Miner damage rule, and a stochastic model for the fatigue life and fatigue limit variability. Algorithms are presented which make it possible to calculate the RFC‐amplitude distribution, based on a Markov Chain approximation of local maxima and minima. The method derived would apply to structures subjected to random fatigue loads such as acoustic noise, random vibration or sea waves, etc.
CONSTITUTIVE EQUATIONS FOR RIGID PLASTIC OR VISCOPLASTIC MATERIALS CONTAINING VOIDS
Authors: Guennouni T. , Francois D.
Published: April 2007

Abstract— A systematic numerical study is reported that uses a homogenization technique to consider the plastic and viscoplastic potential of a porous medium; the study also takes account of the interactions between cavities. Calculations are carried out in plane strain with cylindrical cavities for various stress states characterized by the ratio of the principal stresses and for various values of the porosity as well as of the strain hardening exponent of the matrix.

It is shown that the cavity growth rate is a strong function of the porosity, of the strain hardening exponent of the matrix and that it is a linear function of the stress triaxiality ratio. It is demonstrated that the growth models in an infinite body of Rice and Tracey or of Budiansky et al. can underestimate the cavity growth rate for intermediate stress triaxiality ratios, even for porosities as low as 1%.
CREEP CRACK INITIATION AND GROWTH IN INCONEL 718 ALLOY AT 650°C
Authors: Diboine A. , Pineau A.
Published: April 2007

Creep cracking tests were performed on a nickel base superalloy, Inconel 718, using CT type specimens at 650°C in an air environment. Both time to initiate creep crack propagation (T1) and creep crack growth rate (ȧ) were measured as a function of the stress‐intensity factor, K. It is shown that crack initiation behaviour and early crack growth (stage I) are strongly dependent on test procedures. Furthermore there is no unique correlation between ȧ and K, except in the regime corresponding to relatively high crack growth rates (stage II). This conclusion was reached by conducting tests both under increasing and under decreasing K. The reasons for this behaviour are briefly discussed in relation to environmental effects. A simple model (based upon a theoretical stress‐strain field for creeping cracked solids and the ductility exhaustion concept) is used in an attempt to explain the results. The limitations for the application of this model are discussed. It is shown that this approach can explain a number of experimental results provided that it is accepted that creep ductility is time‐dependent because of environmental effects.

Finally, the results of these crack propagation tests are used in conjunction with the theoretical results derived from the Riedel and Rice analysis to model both crack initiation and crack growth behaviour of Inconel 718 under sustained load.
AN ANALYSIS OF FRICTIONAL EFFECTS ON CYLINDRICAL MODE III FATIGUE CRACK PROPAGATION SPECIMENS
Authors: Gross T. S. , Mendelsohn D.
Published: April 2007

Abstract— A model predicting the magnitude of frictional effects from fracture surface roughness on mode III fatigue crack growth is presened. Analysis of published data indicates that fracture surface roughness of the order of micrometers or less is enough to account for mode III fatigue crack growth retardation observation for increasing crack lengths for growth at constant ΔK. The model suggests that high strength materials will exhibit a greater resistance to shear crack growth than low strength materials. It also suggests that the resistance to shear crack growth will be more prominent at low nominal applied shear stress. The results of the analysis suggest that the concept of similitude does apply to mode III fatigue crack growth when the effects of friction on the stress intensity factor are included.
FRICTIONAL EFFECTS ON FATIGUE CRACK GROWTH IN β ‐ANNEALED Ti‐6Al‐4V
Authors: Gross T. S. , Bose S. , Zhong L.
Published: April 2007

Abstract— The crack tip cyclic heat generation rate, fatigue crack growth rate, and the crack closure stress were measured in a β‐annealed Ti‐6Al‐4V for R ratios of ‐0.1, 0.1 and 0.2. The R= ‐0.1 and 0.1 cases exhibited macroscopic crack closure and the R = 0.2 case exhibited no macroscopic crack closure as measured by strain gage techniques. There was a transition in the slope of the da/dN vs ΔK curve for the closure cases and no transition for the no‐closure case. The crack tip heat generation rate above the transition for the closure cases was an order of magnitude greater than for the no‐closure case. Also the crack tip heat generation rate below the transition was greater for the closure cases than for the no‐closure case. The transition in the heat generation rate and the crack growth rate was attributed to a transition from static frictional locking of shear branch cracks to sliding of the branch crack surfaces. Below the transition the crack faces are locked open creating a large roughness‐induced closure component. When the branch cracks are allowed to undergo reverse shear, the amount of roughness‐induced closure markedly decreases and the fracture surface becomes less tortuous. The relative sliding generates the increased heat.
THE EFFECT OF PRIOR FATIGUE CYCLING ON TENSILE PROPERTIES OF COPPER AND ALUMINIUM WIRES
Authors: Kumar V. M. , Gupta N. K.
Published: April 2007

Abstract— Having previously been subjected to cyclic loading below the elastic limit, wire specimens of aluminium and copper were subjected to uniaxial tension tests. The results obtained are presented with a view to studying the accumulated changes in stress‐strain behaviour during fatigue. The data obtained for virgin as well as for cyclic preloaded specimens were fitted to the Ramberg‐Osgood relation and useful empirical relationships were developed between its parameters and the prior cyclic stress amplitude as well as the number of prior fatigue cycles. Using these relations, progressive changes in the width and the area of hysteresis loops have been computed and the results obtained have been compared with the experiments.
THERMAL FATIGUE OF MAR‐M509 SUPERALLOY—I. THE INFLUENCE OF SPECIMEN GEOMETRY
Authors: Rezai‐Aria F. , François M. , Rémy L.
Published: April 2007

Abstract— The thermal fatigue behaviour of a cast cobalt superalloy was investigated. Wedge type specimens were tested on a rig using flame heating. A standard cycle from 200 to 1100°C was used for most tests and the specimen geometry was changed to investigate a broad range of thermal fatigue lives. The maximum temperature was also varied for a single specimen geometry. The thermal fatigue life to create a 1 mm deep crack ranges from a few tens to one thousand cycles. Crack initiation occurs early in life at oxidised interdendritic carbides as in high‐temperature, low‐cycle fatigue. Precipitation of small chromium‐rich carbides was found to occur in the dendrites during thermal fatigue cycling. An identical precipitate distribution could be induced by a two stage thermal treatment as shown by quantitative metallography. The isothermal stress‐strain behaviour at high temperature was so shown to be almost insensitive to the microstructure changes induced by thermal fatigue.
A NON‐LINEAR CONTINUOUS FATIGUE DAMAGE MODEL
Authors: Chaboche J. L. , Lesne P. M.
Published: April 2007

Abstract— ‐A non‐linear cumulative fatigue damage model proposed previously is applied to different steels and various loading situations, including two‐level tests and block‐programs. Its ability to describe all the main features of fatigue damage and the ease of its practical use for engineers are discussed and several examples cited. The relationship with other formulations are pointed out together with the main advantages of the proposed model. A generalization is proposed for both cyclic temperature and multiaxial loading conditions.
A TORSION‐BENDING LOADING FRAME FOR A UNIAXIAL FATIGUE TEST MACHINE
Authors: Yates J. R. , Miller K. J.
Published: April 2007

Abstract— A novel mixed‐mode loading frame has been designed to fit a uniaxial servo‐hydraulic test machine. The frame allows fatigue tests to be performed on circurnferentially slit round bars under combined in‐phase torsion and bending loads at positive mean stresses. The growth of fatigue cracks was monitored using a direct current potential drop technique. An empirical equation relating crack depth and voltage is presented.
A MICROSTRUCTURALLY‐SHORT FATIGUE CRACK GROWTH EQUATION
Authors: Navarro A. , de los Rios E. R.
Published: April 2007

Abstract— A brief outline of a recently developed model which describes the microstructurally short and the physically short crack periods of fatigue crack growth is presented. A single equation to describe both regimes is discussed and the model applied to data on a medium carbon steel. Good predictions relating to the actual experimental lifetime were achieved. The results are compared with the prediction of fatigue life based on a previously reported two‐equation approach.