Neutron scattering in engineering applications

Webster, G. A.; Ezeilo, A.N.

doi:10.1016/s0921-4526(96)01221-5

Cited by 19 publications

(8 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Neutron strain scanning is already established as an excellent method for nondestructive 3D probing of stresses existing within bulk engineered components [8][9][10][11]. In this method, the crystal lattice is used as a built in sensor capable of detecting minor elastic distortions of the crystal lattice (changes of interplanar spacing) due to the effect of stress (Fig.…”

Section: Neutron Strain Scanning Methodsmentioning

confidence: 99%

“…The direct calculation of stress from the piece-wise measured elastic strains using equations 2-5 is the common approach widespread in the literature [8][9][10][11]. Its main advantage is that the calculated stress state originates directly from the elastic strains measured in particular measurement points.…”

Section: Figure 15 Herementioning

confidence: 99%

“…Since we were interested in internal stress changes with temperature, all destructive methods were naturally excluded. Probably the best experimental method for such a task is neutron strain scanning [8][9][10][11]. We performed conceptual neutron strain scanning experiments on steel plate coupons with a single NiTi insert exposed to varying temperature [4] and stress [5].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Internal stresses in steel plate generated by shape memory alloy inserts

et al. 2012

View full text Add to dashboard Cite

Neutron strain scanning was employed to investigate the internal stress fields in steel plate coupons with embedded prestrained superelastic NiTi shape memory alloy inserts. Strain fields in steel were evaluated at T=21°C and 130 °C on virgin coupons as well as on mechanically and thermally fatigued coupons. Internal stress fields were evaluated by direct calculation of principal stress components from the experimentally measured lattice strains as well as by employing inverse FE modelling approach. It is shown that if the NiTi inserts are embedded into the elastic steel matrix following a carefully designed technological procedure, the internal stress fields vary with temperature in a reproducible and predictable way. It is estimated that this mechanism of internal stress generation can be safely applied in the temperature range from -20 °C to 150 °C and is relatively resistant to thermal and mechanical fatigue. The predictability and fatigue endurance of the mechanism is of essential importance for development of future smart metal matrix composites or smart structures with embedded shape memory alloy components.

show abstract

Section: Neutron Strain Scanning Methodsmentioning

confidence: 99%

Section: Figure 15 Herementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Internal stresses in steel plate generated by shape memory alloy inserts

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Often the determination of the residual stress state, rather than simply the residual strains is the objective. Generally, six independent strain directions are needed to calculate stress, however usually the principal stress directions are known, thus it is sufficient to measure strain along each of these directions [14]. For example, the stress in a principal direction X, is given by:…”

Section: Experimental Methodology and Materialsmentioning

confidence: 99%

A non-destructive method for the measurement of residual strains in semi-crystalline polymer components

Hughes¹,

Heeley²,

Curfs³

2011

Materials Letters

View full text Add to dashboard Cite

A new non-destructive tool is presented, enabling the measurement of locked-in residual strains in semi-crystalline polymer-based components. The technique employs high-energy synchrotron X-rays to probe the variation of diffraction angle within a well-defined 'gauge volume' with a spatial resolution of the order of 1 mm. Lattice strain is calculated from the diffraction angles.An overview of the experimental methodology and underlying principles involved in the nondestructive evaluation of residual strain in polymer-based components is given. Preliminary results show that synchrotron X-rays can be used successfully to measure the internal elastic residual strain field in polymer components, being potentially applicable to other materials. The method was used successfully to measure residual strains in a commercial high density polyethylene gas pipeline sample.

show abstract

“…[1][2][3] The analysis of neutron diffraction profiles can provide some useful microstructural parameters, such as a lattice strain, e hkl , and microscopic strain. 4) The determination of e hkl is based on the measurement of small angular displacements of diffraction peaks caused by small variations in lattice plane spacing, Dd hkl , in a sampled specimen with respect to the stressfree lattice plane spacing, d 0 hkl , (e hkl ϭDd hkl /d 0 hkl ).…”

Section: Introductionmentioning

confidence: 99%

Bauschinger Effect in .ALPHA.-.GAMMA. Dual Phase Alloys Studied by In Situ Neutron Diffraction.

et al. 2002

View full text Add to dashboard Cite

In situ neutron diffraction experiments during tension-compression deformation were performed on five Fe-Cr-Ni alloys with the volume fraction of ferrite (a) ranging from 0.0 to 100 %. Tensile deformation was applied in a step by step manner up to a strain of 1.3-2.0 % followed by compressive deformation, and neutron diffraction spectra were recorded during temporary stops of a deformation machine with fixed crosshead. (111) reflection of austenite and (110) of ferrite, respectively, were measured simultaneously by using a position sensitive detector. Elastic lattice strains in both constituent phases were evaluated from measured diffraction spectra as a function of external load. Based on these experimental results, heterogeneous deformation behavior in the a-g dual phase alloys is discussed considering the Bauschinger effect. It is concluded that large compressive residual lattice strains detected in the g phase after tensile pre-straining, causes the large Bauschinger effect in a-g dual phase alloys.KEY WORDS: in situ strain measurement; neutron diffraction; a-g dual phase alloy; tension-compression deformation; Bauschinger effect.fractometer TKSN400 installed at the medium-power reactor LWR-15 in Nuclear Physics Institute (NPI). A twocrystal sandwich monochromator has permitted us to use neutrons with two different wavelengths simultaneously; l 1 ϭ0.147 nm (Ge(311)) and l 2 ϭ0.27 nm (Si(111)). The diffractometer was also equipped with a deformation device enabling both tensile and compressive tests up to a maximum loading of Ϯ20 kN.The geometric arrangement of the in situ strain measuring system is illustrated in Fig. 1, where width of two Cdmasks was of 2.0 mm. Shape and dimensions of tensioncompression specimens were the same as those used in Ref. 7). Overall specimen strain was measured by means of a strain gauge glued on specimen surface. From here on, it is called macroscopic strain. A specimen was strained in tension in a step-by-step manner up to 0.013-0.020 followed by unloading, and subsequently deformed in compression similarly down to reversed strains of 0.010-0.0013. Diffraction spectra were collected during temporary stops upon a crosshead-fixed regime. An exposure time of 4 ks was necessary to obtain sufficient statistics to perform a reliable analysis of diffraction profiles. After the crosshead was fixed, the applied stress decreased rapidly within 0.4 ks and afterwards slowly by less than 10 MPa as reported in Ref. 7). Such relaxation behavior was observed in all examined cases. Diffraction profiles were measured for 4.0 ks and the uncertainty of the applied stress during the diffraction experiments is then considered to be approximately of 10 MPa. If we employ the testing method with constant load control, the resulting data will suffer from similar ambiguity in strains because of creep deformation. Therefore, such a kind of experimental error cannot be avoided in this case. In the present analysis, the applied stresses and the macroscopic strains recorded after holding time of 4 ks were us...

show abstract

Neutron scattering in engineering applications

Cited by 19 publications

References 8 publications

Internal stresses in steel plate generated by shape memory alloy inserts

Internal stresses in steel plate generated by shape memory alloy inserts

A non-destructive method for the measurement of residual strains in semi-crystalline polymer components

Bauschinger Effect in .ALPHA.-.GAMMA. Dual Phase Alloys Studied by In Situ Neutron Diffraction.

Contact Info

Product

Resources

About