Measuring and testing – Testing by impact or shock
Patent
1996-06-14
1998-06-23
Dombroske, George M.
Measuring and testing
Testing by impact or shock
73 82, G01H 700, G01N 330, G01N 332
Patent
active
057707910
ABSTRACT:
Methods and apparatus for the accurate determination of impact fracture behavior of materials. Test specimens are thermally preconditioned in-situ by flowing a thermally conditioned gas over the surfaces of the specimen which contain the volume of material near the notch and/or precrack which influences the fracture properties. Upper shelf energy is determined using miniature specimens which is quantitatively equivalent to the upper shelf energy which would have been obtained using conventional ASTM E 23 specimens. Percent shear fracture area and lateral expansion are measured using a computerized image capture system to reproduce a digitized image of the fracture surface on a computer which is then quantitatively analyzed. A high frequency response load cell, consisting in part of two active strain gages installed near the center of percussion on the tapered portion of an impact striker, well within one stress wavelength of the striking surface, is used to measure the force-time curve. Balancing resistors are used to complete a Wheatstone bride circuit and these balancing resistors are not mounted on the striker to avoid sensing reflected stress waves. The instrumented striker is calibrated after it is installed in the test machine by placing a calibrated load cell and a hydraulic jack within a load reaction frame which surrounds the instrumented striker, calibrated load cell, and hydraulic jack.
REFERENCES:
patent: 4168620 (1979-09-01), Schrader
patent: 4405243 (1983-09-01), Kuraoka et al.
patent: 4546654 (1985-10-01), Isherwood et al.
patent: 4567774 (1986-02-01), Manahan
patent: 4864867 (1989-09-01), Manahan
patent: 5165287 (1992-11-01), Manahan
ASTM Draft Standard, "Proposed ASTM Standard Method for Instrumented Charpy V-Notch and Miniaturized Charpy V-Notch Impact Tests on Metallic Materials", 1996, Entire Document.
Lucas et. al., "Subsized Bend and Charpy V-Notch Specimens for Irradiated Testing", 1986, pp. 307-310.
Corwin et. al., "Effect of Specimen Size and Material Condition on the Charpy Impact Properties of 9Cr-1Mo-V-Nb Steel", 1986, pp. 332-334.
Manahan, "Miniaturized Charpy Test Optimization for Applications in the Power Industry", Jun., 1995, Entire Report.
ASTM Standard E23-93a, "Standard Test Methods for Notched Bar Impact Testing of Metallic Materials", 1993, pp. 206-219.
Nanstad et al., "Influence of Thermal Conditioning Media on Charpy Specimen Test Temperature", 1990, pp. 195-198.
Kumar et al., "Recent Improvements in Size Effects Correlations for DBTT and Upper Shelf Energy of Ferritic Steels", 1993, pp. 47-59.
Manahan et al., "A Generalized Methodology for Obtaining Quantitative Charpy Data from Test Specimens of Now Standard Dimensions", 1989, pp. 247-256.
Dombroske George M.
Noori Max H.
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