摘要:

AbstractAn experimental investigation into the growth and closure behaviour of small corner cracks has been conducted on a low carbon steel (ASTM A516 Grade 70). This ferritic/pearlitic steel has been chosen to investigate the complexities of small crack behaviour in the dual phase material. Innovative procedures are used for compliance measurement and opening load determination. The closure and growth behaviour of the small corner cracks are presented in terms of shape and size. The results are divided into two stages, the first pertaining to the “stationary crack”, and the second dealing with the crack as it grows. The cracks are shown to exhibit an irregular growth rate, which is in part, shown to correspond with microstructural features of the material. In the short crack regime, the linear fracture mechanics parameter, ΔKdoes not correlate with the data and the use of a ΔKeffbased on the effective applied load provided little improv

ISSN:8756-758X    

DOI:10.1111/j.1460-2695.1995.tb00910.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe boundary element method (BEM) is used to develop an effective calibration method for the localized DCPD crack measurement technique. Electrical potentials are obtained from a three‐dimensional BEM analysis of a flat plate specimen containing a pair of coplanar coalescing surface cracks. This calibration technique is developed as part of a study of fatigue crack propagation and coalescence. The development of this calibration technique is presented with an evaluation based on the experimental result

ISSN:8756-758X    

DOI:10.1111/j.1460-2695.1995.tb00911.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractApproximate equations were developed to describe the stress fields in stress concentration regions. A uniaxial tension loading condition was considered. For infinite bodies, the stress equations contain two parameters, the stress concentration factorKtand the notch root radius ρ; for finite bodies, a finite size correction factorfwwhich involves the notch depth,t, and the length of ligament ahead of the notch tip,d, was introduced. After the approximate equations reach their minimum value, a uniform distribution is assumed. The accuracy of this description of the stress field was verified by comparison with analytical solutions and the results of numerical analysis. The new equations give better estimations of stress fields than currently available approximate expressions

ISSN:8756-758X    

DOI:10.1111/j.1460-2695.1995.tb00912.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe structure and mechanical properties of electrophoretically deposited t‐ZrO2/Al2O3lamellar composites are described. The fracture behavior of, and crack paths in, such composites with strong interfaces has been evaluated using indentation and 4‐point bend tests. The effect of residual and induced stresses is considered. It is shown that significant crack deflection can be obtained in t‐ZrO2/Al2O3composites by incorporating a number of closely spaced, thin Al2O3l

ISSN:8756-758X    

DOI:10.1111/j.1460-2695.1995.tb00913.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractA concept for minimising the error associated with theKgradient and the interval of crack length measurement in fatigue crack growth testing has been extended to include crack configurations where crack size is significant relative to specimen width. This was used to develop a procedure for deriving the da/dnvs. ΔKrelationship from crack growth data. The procedure was applied to several test data, utilizing six measurement points of length vs. cycles data and experimenting with various sizes of crack measurement interval (up to 85% of crack size). The accuracy of the derived da/dnvs. ΔKdata was examined by comparison with the baseline data curves. The results were within a few per cent of the actual test data and were usually more accurate than those obtained by secant methods. Increasing the number of data points used in the analysis generally improved the accuracy of the present procedure more than it did with the standard secant method result

ISSN:8756-758X    

DOI:10.1111/j.1460-2695.1995.tb00914.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:8756-758X    

DOI:10.1111/j.1460-2695.1995.tb00899.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY