Methodology to obtain constant stress triaxiality during cruciform biaxial testing with center pocket specimen

Published

October 10, 2023

Author(s)

Dilip K. Banerjee, Jinjae Kim, Jordan Hoffman, Mark Iadicola, Brad Kinsey, Jinjin Ha

Abstract

A multi-interpolation method is proposed to determine the displacement trajectory along each axis of a cruciform specimen with the goal to achieve a linear stress path, corresponding to a constant stress triaxiality, in the center of the custom designed, non-standard specimen during in-plane biaxial testing. Finite element simulations are used to obtain the stress path from the given displacement trajectory. In every iteration, the displacement trajectory is updated using the interpolation between the target stress path and adjacent ones on each side of the curve. The iterations are repeated until a linearity tolerance is satisfied. In this study, the material is an austenitic stainless steel, SS316L, with a Hockett-Sherby isotropic hardening model and Yld2004-18p non-quadratic anisotropic yield function. The method is demonstrated on five stress states, including pure shear, biaxial compression/tension, and uniaxial, plane-strain, and equibiaxial tension. The results show the successful determination of a displacement trajectory for the non-standard cruciform specimen so that a linear stress path and constant triaxiality at the center area are achieved.

Citation

JOM Journal of the Minerals Metals and Materials Society

Pub Type

Journals

Download Paper

https://doi.org/10.1007/s11837-023-06158-x

Local Download

Keywords

biaxial test, cruciform specimen, stress triaxiality, finite element analysis.

Citation

Banerjee, D. , Kim, J. , Hoffman, J. , Iadicola, M. , Kinsey, B. and Ha, J. (2023), Methodology to obtain constant stress triaxiality during cruciform biaxial testing with center pocket specimen, JOM Journal of the Minerals Metals and Materials Society, [online], https://doi.org/10.1007/s11837-023-06158-x, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956183 (Accessed October 27, 2025)