摘要:

This paper reviews recent work on the effect of biaxial stress on magnetic properties obtained from hysteresis loops. Both experimental and theoretical work are discussed. Biaxial stress measurements were performed on SAE-4130 and mild steel cruciform specimens. The theoretical model, applied to polycrystalline steels, reduces the problem to that of computing an effective stress and substituting that effective stress into the Schneider-Cannell-Watts model for uniaxial stress. The effective stress under biaxial stress is equal to plus or minus one of the deviatoric (i.e distortional) normal stress components. depending on whether tension or compression acts. and depending on which of the normal stress axes is parallel to the applied magnetic field. Computer results are compared to experimental results. Good qualitative agreement is found.An NDE procedure for determining the biaxial stress difference from magnetic properties is discussed.

ISSN:1058-9759    

DOI:10.1080/10589759508952837

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A number of power laws for ultrasonic attenuation have been proposed in the non-destructive evaluation (NDE) literature empirically or derived analytically, for various regimes of wavelength relative to size of inhomogeneity. In this paper we view these laws in a unifying framework and analyse published data on the dependence of ultrasonic attenuation on inspection frequency and parameters describing the microstructure of an inspected solid by using generalised dimensional analysis based on various "self-similarity hypotheses". We establish universal power laws for newly defined NDE variables, involving attenuation derivatives. These variables are readily accessible to measurement and can be of great importance when characterising the solid's microstructure and, specifically, stages of damage accumulation. All the corresponding powers are found by curve-fitting techniques or by reference to known experimental results. They depend on the conditions of the experiment.

ISSN:1058-9759    

DOI:10.1080/10589759508952838

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

THE JAPANESE SOCIETY OF NON-DESTRUCTIVE INSPECTION (JSNDI) THE 12TH INTERNATIONAL ACOUSTIC EMISSION SYMPOSIUM

ISSN:1058-9759    

DOI:10.1080/10589759508952839

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:1058-9759    

DOI:10.1080/10589759508952840

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The oxidation behavior of a cold rolled motor lamination (CRML) steel was investigated in a simulated exothermic atmosphere and a nitrogen/hydrogen atmosphere. The weight gain and the surface composition after annealing were studied using Thermo-gravimetric Analysis (TGA) and X-ray photoelectron spectroscopy (XPS). respectively. We found that annealing in the exothermic atmosphere increased the surface oxidation. The nitrogen/hydrogen annealing atmosphere significantly reduced the surface oxidation.

ISSN:1058-9759    

DOI:10.1080/10589759508952841

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A new nondestructive technique for monitoring the hydration process of cement within concrete and measurement of the compressive strength of concrete is presented. The technique called the Nuclear Magnetic Resonance (NMR) has so far been primarily used in the fields of chemistry and medicine. Its application to construction materials has been very limited or nonexistent. In this study, NMR is used to monitor the. hydration of cement paste in concrete with two different water cement ratios. The first objective of this study was to distinguish between the amounts of remaining free water, and water consumed in the hydration process during the 28 days monitoring period. The second objective was to relate the compressive strength of concrete to NMR signals. A number of standard compression tests were performed in parallel with the NMR tests. Correlation of the responses from nondestructive tests with NMR and those of standard compression tests indicated almost a linear relationship.

ISSN:1058-9759    

DOI:10.1080/10589759508952842

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor