Pendulum Impact Testing Machine 750j ASTM E1820 Standard Test Method for Measurement of Fracture Toughness Pit752h

Pendulum Impact Testing Machine 750J ASTM E2298 Instrumented Impact Testing of Metallic Materials PIT752H

Application:

 
Standards
ASTM E23, ASTM E1820, ASTM E2298,
ISO 148, EN10045, ISO 148, EN10045, ISO 14556, JIS Z 2242, GOST 9454-78
 

ASTM E1820 Standard Test Method for Measurement of Fracture Toughness

1. Scope
1.1 This test method covers procedures and guidelines for the determination of fracture toughness of metallic materials using the following parameters: K, J, and CTOD (d). Toughness can be measured in the R-curve format or as a point value. The fracture toughness determined in accordance with this test method is for the opening mode (Mode I) of loading.
1.2 The recommended specimens are single-edge bend, [SE(B)], compact, [C(T)], and disk-shaped compact, [DC(T)]. All specimens contain notches that are sharpened with fatigue cracks.
1.2.1 Specimen dimensional (size) requirements vary according to the fracture toughness analysis applied. The guidelines are established through consideration of material toughness, material flow strength, and the individual qualification requirements of the toughness value per values sought.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate
safety and health practices and determine the applicability of regulatory limitations prior to use.

4. Summary of Test Method
4.1 The objective of this test method is to load a fatigue precracked test specimen to induce either or both of the following responses (1) unstable crack extension, including
significant pop-in, referred to as "fracture instability" in this test method; (2) stable crack extension, referred to as "stable tearing" in this test method. Fracture instability results in a single point-value of fracture toughness determined at the point of instability. Stable tearing results in a continuous fracture toughness versus crack-extension relationship (R-curve) from which significant point-values may be determined. Stable tearing interrupted by fracture instability results in an R-curve up to the point of instability.
4.2 This test method requires continuous measurement of force versus load-line displacement or crack mouth opening displacement, or both. If any stable tearing response occurs, then an R-curve is developed and the amount of slow-stable crack extension shall be measured.
4.3 Two alternative procedures for measuring crack extension are presented, the basic procedure and the resistance curve procedure. The basic procedure involves physical marking of the crack advance and multiple specimens used to develop a plot from which a single point initiation toughness value can be evaluated. The resistance curve procedure is an elasticcompliance method where multiple points are determined from a single specimen. In the latter case, high precision of signal resolution is required. These data can also be used to develop an R-curve. Other procedures for measuring crack extension are allowed.
4.4 The commonality of instrumentation and recommended testing procedure contained herein permits the application of data to more than one method of evaluating fracture toughness. Annex A4-Annex A11 define the various data treatment options that are available, and these should be reviewed to optimize data transferability.
4.5 Data that are generated following the procedures and guidelines contained in this test method are labeled qualified data. Data that meet the size criteria in Annex A4-Annex A11 are insensitive to in-plane dimensions.
4.6 Supplementary information about the background of this test method and rationale for many of the technical requirements of this test method are contained in (3). The formulas presented in this test method are applicable over therange of crack size and specimen sizes within the scope of this test method.

Significance of instrumentation impact test system
Compared with traditional pendulum impact testing machine, instrumented type is more useful for accurate analysis of material property during crack, facilitating the engineers to understand the most fragile part of materials when developing new materials.
In addition to providing an measure of total absorbed energy (Wt), instrumented testing enables the determination of characteristic force, energy, and displacement parameters, such as the pre-maximum force energy (Wm); the post maximum force energy; the general yield force (Fgy); the force at brittle fracture initiation (Fbf); the arrest force (Fa).
Wance is the leading R&D and manufacturing of instrumented impact testing system in China, and has experienced experts for force transducer design. Combined with our high speed data sampling system, Wance provides the full complement of solutions for laboratory, ranging from 0.1J for engineering plastic to 100,000J for steel DWTT test.
 
Machine structure
The basic model consists of a heavy steel base on which the specimen holder (anvil) and a heavy-duty cast steel upright are mounted.
 
 
Framework
The framework is processed with one body casting. Front and rear columns are symmetric with single beam support axis, with high stiffness and precision.
The framework is made from ductile cast iron with high strength and stiffness, and with good capability of vibration absorbing.
The seat mass is 822kg, 15 times than 750J pendulum mass (54.65), fully complying with standards that seat mass must be 12 times than pendulum mass.
 
Pendulum
Pendulum is designed with 3D CAD software, greatly ensuring the striking center accuracy and pendulum moment precision. High strength pendulum rod highly reduces vibration after impact.