A Dispersant Effectiveness Test Based on the Drop-Weight Interfacial Tension Test Method

This paper reports results of tests on flow and ductile fracture of a very high toughness steel with Charpy V-notch absorbed energy (CVN energy) at room temperature of 471 J. The microstructure of the steel is bainite/ferrite and its strength is equivalent to X80 grade. The flow stress was determined using tensile tests at temperatures between 150°C and −147°C and strain rates of 0.00075, 0.02 and 1 s−1, and was fitted to a proposed constitutive equation. Charpy tests were carried out at an initial impact velocity of 5.1 ms−1 using drop-weight machines (maximum capacity of 842 J and 4029 J). The samples were not broken during the test, i.e. they passed through the anvils after significant bending deformation with only limited crack growth. Most of the absorbed energy was due to deformation. There was little effect of excess energy on absorbed energy up to 80% of machine capacity (i.e. the validity limit of ASTM E 23). As an alternative to the CVN energy, the crack tip opening angle (CTOA) measured using the drop-weight tear test (DWTT) has been proposed as a material parameter to characterize crack propagation resistance. Preliminary work on evaluating CTOA using the two-specimen CTOA test method is presented. The initiation energy is eliminated by using statically precracked test specimens. Account is taken of the geometry change of the specimens (e.g. thickening under the hammer) on the rotation factor and of the effect of strain rate on flow stress.

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Tension Test Method and Thermal Degrandation of Fatigue Strength for Unidirectional CFRP Ring

Journal of the Society of Materials Science Japan ◽

10.2472/jsms.53.806 ◽

2004 ◽

Vol 53 (7) ◽

pp. 806-811

Author(s):

Tomohiro NARUSE ◽

Toshio HATTORI ◽

Haruo MIURA ◽

Kazuki TAKAHASHI

Keyword(s):

Fatigue Strength ◽

Tension Test ◽

Test Method

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An Innovative Test Method for Tensile Strength of Concrete by Applying the Strut-and-Tie Methodology

Materials ◽

10.3390/ma13122776 ◽

2020 ◽

Vol 13 (12) ◽

pp. 2776 ◽

Cited By ~ 1

Author(s):

Wen-Cheng Liao ◽

Po-Shao Chen ◽

Chung-Wen Hung ◽

Suyash Kishor Wagh

Keyword(s):

Tensile Strength ◽

Test Methods ◽

Standard Test ◽

Strength Test ◽

Tension Test ◽

Test Method ◽

Direct Tension ◽

Direct Tension Test ◽

Strut And Tie ◽

Tensile Strength Test

Tensile strength is one of the important mechanical properties of concrete, but it is difficult to measure accurately due to the brittle nature of concrete in tension. The three widely used test methods for measuring the tensile strength of concrete each have their shortcomings: the direct tension test equipment is not easy to set up, particularly for alignment, and there are no standard test specifications; the tensile strengths obtained from the test method of splitting tensile strength (American Society for Testing and Materials, ASTM C496) and that of flexural strength of concrete (ASTM C78) are significantly different from the actual tensile strength owing to mechanisms of methodologies and test setup. The objective of this research is to develop a new concrete tensile strength test method that is easy to conduct and the result is close to the direct tension strength. By applying the strut-and-tie concept and modifying the experimental design of the ASTM C78, a new concrete tensile strength test method is proposed. The test results show that the concrete tensile strength obtained by this proposed method is close to the value obtained from the direct tension test for concrete with compressive strengths from 25 to 55 MPa. It shows that this innovative test method, which is precise and easy to conduct, can be an effective alternative for tensile strength of concrete.

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Statistical Distribution of Failure Stress Values from Superpave® Direct Tension Test

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1810-09 ◽

2002 ◽

Vol 1810 (1) ◽

pp. 72-77

Author(s):

Raj Dongré ◽

Charles Antle

Keyword(s):

Weibull Distribution ◽

Standard Test ◽

Tension Test ◽

Failure Stress ◽

Test Method ◽

Direct Tension ◽

Data Set ◽

Direct Tension Test ◽

Data Points ◽

Made In

A statistically robust method was developed using the Weibull distribution to identify and eliminate outliers from the failure stress determinations. The method is applicable to any failure stress data set that follows the Weibull distribution; however, in this application, it was developed for the AASHTO standard test method for conducting the direct tension test (DTT). A large number of stress-at-failure measurements with the DTT were made in the course of instructing users of this device. These data, all for the same asphalt, provided the means for studying the nature of the distribution of the breaking strength of these asphalt specimens. The training database contains more than 900 data points. The current AASHTO practice of eliminating the lowest two stress values was found to be reasonable. However, it is an arbitrary method that may lead to problems in the future. On the basis of the results of this study, the procedure is recommended for use and implementation in the next AASHTO version of the DTT standard.

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