FORMAT
BOOKS
PACKAGES
EDITION
PUBLISHER
CONTENT TYPE
Act
Admin Code
Announcements
Bill
Book
CADD File
CAN
CEU
Charter
Checklist
City Code
Code
Commentary
Comprehensive Plan
Conference Paper
County Code
Course
DHS Documents
Document
Errata
Executive Regulation
Federal Guideline
Firm Content
Guideline
Handbook
Interpretation
Journal
Land Use and Development
Law
Legislative Rule
Local Amendment
Local Code
Local Document
Local Regulation
Local Standards
Manual
Model Code
Model Standard
Notice
Ordinance
Other
Paperback
PASS
Periodicals
PIN
Plan
Policy
Product
Program
Provisions
Requirements
Revisions
Rules & Regulations
Standards
State Amendment
State Code
State Manual
State Plan
State Standards
Statute
Study Guide
Supplement
Technical Bulletin
All
|
Description of ASTM-C1576 2010ASTM C1576 - 05(2010)Standard Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress Flexural Testing (Stress Rupture) at Ambient TemperatureActive Standard ASTM C1576 | Developed by Subcommittee: C28.01 Book of Standards Volume: 15.01 ASTM C1576Significance and Use The service life of many structural ceramic components is often limited by the subcritical growth of cracks. This test method provides an approach for appraising the relative slow crack growth susceptibility of ceramic materials under specified environments at ambient temperature. Furthermore, this test method may establish the influences of processing variables and composition on slow crack growth as well as on strength behavior of newly developed or existing materials, thus allowing tailoring and optimizing material processing for further modification. In summary, this test method may be used for material development, quality control, characterization, design code or model verification, and limited design data generation purposes. Note 4Data generated by this test method do not necessarily correspond to crack velocities that may be encountered in service conditions. The use of data generated by this test method for design purposes, depending on the range and magnitude of applied stresses used, may entail extrapolation and uncertainty. This test method is related to Test Method C1368 ( constant stress-rate flexural testing ), however, C1368 uses constant stress rates to determine corresponding flexural strengths whereas this test method employs constant stress to determine corresponding times to failure. In general, the data generated by this test method may be more representative of actual service conditions as compared with those by constant stress-rate testing. However, in terms of test time, constant stress testing is inherently and significantly more time- consuming than constant stress rate testing. The flexural stress computation in this test method is based on simple elastic beam theory, with the assumptions that the material is isotropic and homogeneous, the moduli of elasticity in tension and compression are identical, and the material is linearly elastic. The grain size should be no greater than one fiftieth (1/50) of the beam depth as measured by the mean linear intercept method ( E112 ). In cases where the material grain size is bimodal or the grain size distribution is wide, the limit should apply to the larger grains. The test specimen sizes and test fixtures have been selected in accordance with Test Methods C1161 and C1368 , which provides a balance between practical configurations and resulting errors, as discussed in Refs. (4,5). The data are evaluated by regression of log applied stress vs. log time to failure to the experimental data. The recommendation is to determine the slow crack growth parameters by applying the power law crack velocity function. For derivation of this, and for alternative crack velocity functions, see Appendix X1. Note 5A variety of crack velocity functions exist in the literature. A comparison of the functions for the prediction of long-term static fatigue data from short-term dynamic fatigue data [6] indicates that the exponential forms better predict the data than the power-law form. Further, the exponential form has a theoretical basis [7-10], however, the power law form is simpler mathematically. Both have been shown to fit short-term test data well. The approach used in this method assumes that the material displays no rising R-curve behavior, that is, no increasing fracture resistance (or crack-extension resistance) with increasing crack length. The existence of such behavior cannot be determined from this test method. The analysis further assumes that the same flaw type controls all times-to-failure. Slow crack growth behavior of ceramic materials can vary as a function of mechanical, material, thermal, and environmental variables. Therefore, it is essential that test results accurately reflect the effects of specific variables under study. Only then can data be compared from one investigation to another on a valid basis, or serve as a valid basis for characterizing materials and assessing structural behavior. Like strength, time to failure of advanced ceramics subjected to slow crack growth is probabilistic in nature. Therefore, slow crack growth that is determined from times to failure under given constant applied stresses is also a probabilistic phenomenon. The scatter in time to failure in constant stress testing is much greater than the scatter in strength in constant stress-rate (or any strength) testing (Refs. (1, 11-13)), see Appendix X2. Hence, a proper range and number of constant applied stresses, in conjunction with an appropriate number of test specimens, are required for statistical reproducibility and reliable design data generation (Ref. (1-3)). This standard provides guidance in this regard. The time to failure of a ceramic material for a given test specimen and test fixture configuration is dependent on its inherent resistance to fracture, the presence of flaws, applied stress, and environmental effects. Fractographic analysis to verify the failure mechanisms has proven to be a valuable tool in the analysis of SCG data to verify that the same flaw type is dominant over the entire test range (Refs. 14 and 15), and it is to be used in this standard (refer to Practice C1322 ). 1. Scope 1.1 This standard test method covers the determination of slow crack growth (SCG) parameters of advanced ceramics by using constant stress flexural testing in which time to failure of flexure test specimens is determined in four-point flexure as a function of constant applied stress in a given environment at ambient temperature. In addition, test specimen fabrication methods, test stress levels, data collection and analysis, and reporting procedures are addressed. The decrease in time to failure with increasing applied stress in a specified environment is the basis of this test method that enables the evaluation of slow crack growth parameters of a material. The preferred analysis in the present method is based on a power law relationship between crack velocity and applied stress intensity; alternative analysis approaches are also discussed for situations where the power law relationship is not applicable.
ASTM Standards C1145 Terminology of Advanced Ceramics C1161 Test Method for Flexural Strength of Advanced Ceramics at Ambient Temperature C1322 Practice for Fractography and Characterization of Fracture Origins in Advanced Ceramics C1368 Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress-Rate Strength Testing at Ambient Temperature C1465 Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress-Rate Flexural Testing at Elevated Temperatures E4 Practices for Force Verification of Testing Machines E6 Terminology Relating to Methods of Mechanical Testing E112 Test Methods for Determining Average Grain Size E337 Test Method for Measuring Humidity with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures) E399 Test Method for Linear-Elastic Plane-Strain Fracture Toughness K Ic of Metallic Materials E1823 Terminology Relating to Fatigue and Fracture Testing Keywords Advanced ceramics; slow crack growth; slow crack growth parameters; time to failure; four-point flexure; flexural testing; constant stress testing; Advanced ceramics; Constant stress-rate flexural testing; Flexural testing--ceramics; Four-point flexure; Slow crack growth (SCG); Stress rupture; Time-to-failure (TTF); Advanced ceramics; Constant stress-rate flexural testing; Flexural testing--ceramics; Four-point flexure; Slow crack growth (SCG); Stress rupture; Time-to-failure (TTF); ICS Code ICS Number Code 81.060.30 (Advanced ceramics) DOI: 10.1520/C1576-05R10 ASTM International is a member of CrossRef. ASTM C1576The following editions for this book are also available...
This book also exists in the following packages...Subscription InformationMADCAD.com ASTM Standards subscriptions are annual and access is unlimited concurrency based (number of people that can access the subscription at any given time) from single office location. For pricing on multiple office location ASTM Standards Subscriptions, please contact us at info@madcad.com or +1 800.798.9296.
Some features of MADCAD.com ASTM Standards Subscriptions are: - Immediate Access: As soon as the transaction is completed, your ASTM Standards Subscription will be ready for access.
For any further information on MADCAD.com ASTM Standards Subscriptions, please contact us at info@madcad.com or +1 800.798.9296.
About ASTMASTM International, formerly known as the American Society for Testing and Materials (ASTM), is a globally recognized leader in the development and delivery of international voluntary consensus standards. Today, some 12,000 ASTM standards are used around the world to improve product quality, enhance safety, facilitate market access and trade, and build consumer confidence. ASTM’s leadership in international standards development is driven by the contributions of its members: more than 30,000 of the world’s top technical experts and business professionals representing 150 countries. Working in an open and transparent process and using ASTM’s advanced electronic infrastructure, ASTM members deliver the test methods, specifications, guides, and practices that support industries and governments worldwide. |
GROUPS
|