Open AccessHigh Strain‐Rate Material Model Validation for Laser Peening Simulation
Author(s) -
Langer Kristina,
Olson Steven,
Brockman Robert,
Braisted William,
Spradlin Thomas,
Fitzpatrick Michael E.
Publication year - 2015
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2015.0118
Subject(s) - split hopkinson pressure bar , strain rate , peening , materials science , laser peening , shock (circulatory) , residual stress , structural engineering , stress (linguistics) , bar (unit) , shot peening , laser , composite material , optics , engineering , geology , physics , medicine , linguistics , philosophy , oceanography
Finite element modeling can be a powerful tool for predicting residual stresses induced by laser peening; however the sign and magnitude of the stress predictions depend strongly on how the material model captures the high strain rate response. Although a Johnson‐Cook formulation is often employed, its suitability for modeling phenomena at very high strain rates has not been rigorously evaluated. In this paper, we address the effectiveness of the Johnson‐Cook model, with parameters developed from lower strain rate material data (∼10 3 s –1 ), to capture the higher strain rate response (∼10 5 –10 6 s –1 ) encountered during the laser peening process. Published Johnson‐Cook parameters extracted from split Hopkinson bar testing were used to predict the shock response of aluminum samples during high‐impact flyer plate tests. Additional quasi‐static and split Hopkinson bar tests were also conducted to study the model response in the lower strain rate regime. The overall objective of the research was to ascertain whether a material model based on conventional test data (quasi‐static compression testing and split Hopkinson bar measurements) can credibly be used in FE simulations to predict laser peen‐induced stresses.