5.1 Structural integrity assessments typically use values of strength and elastic modulus to predict crack initiation in graphite components and there is a suite of ASTM standards (Section 2, Test Methods C651, C695, C747, C749, C769, and D7775) to cover the measurement of these properties.5.2 The graphite component behavior after crack initiation depends on fracture mechanics parameters, such as fracture toughness and the work of fracture. Test Method D7779 provides the specification and requirements for measuring the fracture toughness of graphite based on linear-elastic stress analysis. Moreover, Test Method D7779 applies to cases where there are no restrictions on specimen size and on applicable machining and specimen preparation techniques.5.3 Most polycrystalline graphites are non-linear elastic, non-uniform, quasi-brittle materials. For such materials, an effective approach for the determination of fracture properties is the analysis of the global energy balance associated with crack extension, similar to Griffith's theory of brittle fracture. This approach does not have the mathematical complexity of the non-linear elastic fracture and is easier to implement in practice.5.4 Work of Fracture, γf (J/m2), is defined as the energy required to form a crack divided by the cross sectional area of the crack. It is assumed that the energy per unit area is constant during crack propagation. In general, components that have an excess of strain energy to the point of fracture, compared to the work needed to extend the crack to full dimension, fail by fast fracture. Any excess energy is converted into kinetic energy through a process that generates stress waves. If the amount of excess energy is sufficiently large, the stress waves will have peak magnitudes greater than the material strength, leading to the initiation and propagation of secondary cracks that could result in the fragmentation of the component.5.5 However, some components that have less strain energy at the point of fracture than the work needed to extend the crack to full dimension, fail in a quasi-brittle manner and result in stable cracks, crack bridging and distributed micro-cracking. Graphite components are generally tested in their as-manufactured state and fail somewhere between these extremes showing fast fracture with relatively minor amounts of secondary cracking and little tendency to fragment. The change in the WoF and strain rate of graphite components in a reactor environment is important in assessing the component’s tendency for secondary cracking and fragmentation.1.1 This guide provides general tutorial information and best practice for measuring the work of fracture on manufactured graphite and carbon specimens. Although applicable to all carbon and graphite materials, this guide is aimed specifically at measurements required on nuclear graphites, where there may be constraints on the geometry and/or volume of the test specimen.1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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PLUS 8300 Introduction - The Purpose of This Workbook The Publication CAN/CSA-Q830, A Model Code for the Protection of Personal Information, referred to as the CSA Code, (a) provides the principles for the management of personal information; (b)

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This specification covers the design testing of mechanical and electrical characteristics of structure-mounted insulating work platforms for electrical workers in conjunction with personal protective equipment while working on energized circuits. This shall include, but not limited to, insulating gloves with protectors or insulating and insulated hotsticks, or both and a fall protection device that does not compromise the electrical insulating protection of the platform. The platforms shall be subjected to electrical test to determine the leakage current and the ability of the specimen to withstand certain alternating-current potential without flashover between electrodes. Mechanical test shall also be conducted to allow deflection measurement under controlled loading and to determine the ability of the platform to withstand this loading without visible damages such as cracks, delamination, permanent deformation, or discoloration.1.1 This specification covers the design testing of mechanical and electrical characteristics of structure-mounted insulating work platforms used by electrical workers.1.2 Platforms covered by this specification are singleworker platforms not exceeding 9 ft (2.75 m) in length. Platforms designed to support more than one worker at a time are beyond the scope of this specification.1.3 Non-insulating platforms are not within the scope of this specification.1.4 The use and maintenance of this equipment are beyond