Session: CS-07-03: Recent Developments in ASME Codes and Standards - 3

Paper Number: 84861

84861 - A Viscoplastic Model for Alloy 800H for Use With the Section III, Division 5 Design by Inelastic Analysis Methods for Class A Components 

Recently, the ASME approved a new non mandatory appendix to Section III, Division 5, Subsection HB, Subpart B of the ASME Boiler & Pressure Vessel Code providing guidance on the Division 5 design by inelastic analysis methods for Class A components.  This appendix provides guidance on constructing and validating nonlinear constitutive models for use with the Code rules as well as approved material models the designer can use without additional validation.  An eventual goal for the new appendix is to provide reference models for all the HBB Class A materials.  This paper describes an inelastic constitutive model for Alloy 800H, suitable for use with the design by inelastic analysis methods.  The model uses a unified viscoplastic form and a detailed kinematic hardening model to capture the key features of high temperature cyclic behavior in Alloy 800H.  At lower temperatures the model switches to a rate independent reponse to better capture the available experimental data.  The paper describes the model form, calibration database, and details how the model was calibrated and validated against experiment data.  The goal for this model is to incorporate it into the ASME Code, via the newly approved appendix to Subsection HB, Subpart B, to continue to expand the range of prebuilt constitutive models available to designers. 

Presenting Author: Mark Messner Argonne National Laboratory

Presenting Author Biography: Mark Messner is a researcher at Argonne National Laboratory focusing on modeling, simulating, and designing high temperature materials and structures. His research areas include mesostuctural modeling, structural and material design and optimization, machine learning for design problems, the development of simulation methods, and engineering design method development.<br/><br/>He develops and maintains simulation tools for engineering-scale material simulation (NEML) and a crystal plasticity finite element method (CPFEM) package integrated into the open-source MOOSE simulation framework. He also develops tools for calibrating material models to large experimental databases and several material and structural optimization tools.<br/><br/>He participates as a member and chair of several of the ASME Section III Boiler and Pressure Vessel Code working groups responsible for high temperature design methods and has published more than 30 peer reviewed articles.

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