Phase II Results of an Analytical Round Robin for Elastic-Plastic Analysis of Surface Cracked Plates

Abstract

Abstract The second phase of an analytical round robin for the elastic-plastic analysis of surface cracks in flat plates was conducted under the auspices of ASTM Interlaboratory Study 732. The interlaboratory study (ILS) had ten participants with a broad range of expertise and experience, and experimental results from a surface crack tension test in 4142 steel plate loaded well into the elastic-plastic regime provided the basis for the study. The participants were asked to evaluate a surface crack tension test according to the version of the surface crack initiation toughness testing standard published at the time of the ILS, ASTM E2899-13, Standard Test Method for Measurement of Initiation Toughness in Surface Cracks under Tension and Bending. Data were provided to each participant that represented the fundamental information that would be provided by a mechanical test laboratory prior to evaluating the test result. Participants were asked to interpret the test according to E2899, including evaluation of crack-front constraint, determination of a critical initiation angle along the crack front, determination of the deformation regime of the test, and determination of the critical J-integral value. The choice of finite element analysis constitutive models and treatment of the stress-strain data was left to the discretion of the participants. The hope was that this process would familiarize participants with the standard and provide the task group with very helpful feedback regarding the interpretation of the requirements as they are written. Overall the participants’ test analysis results were in good agreement and constructive feedback was received that has resulted in an improved published version of the standard E2899-15.