ORALS

Computational modeling of the damage response of a heterogeneous and anisotropic glass-reinforced plastics (GRP) under shock and impact is complex. Tsai et al [1] employed a plate impact test configuration to study shock wave propagation in a S-2 glass fiber – polyester matrix composite. They observed “Hugoniot Elastic Limit (HEL)” like points in the VISAR (“free surface velocity profiles”) data. The interpretations of experimentally observed HEL and nonlinearity in the data for two different GRP thicknesses at a range of impact velocities require further investigation remained speculative and inconclusive. Recently, Scott et al., [2] performed computational modeling of the plate impact tests with continuum damage mechanics based hyperelastic constitutive equations in ALE 3D finite element code [3]. The parameters for strain-based damage initiation and propagation models to describe: matrix shear cracking and volume expansion under compressive loading conditions, delamination, and fiber breaking in tension and shear were calibrated through comparisons between the VISAR data and computed free surface velocity profiles. Based on the simulation results, Scott et al., suggested that the HEL point is due to elastic-elastic cracking (EEC) of the matrix materials under compressive loading. In simulations, the damage (microcracking of the matrix) emanates from the impact plane and progressively damage the GRP target plate in the plate impact experiments. Fraser [4] implemented the hyperelasticity damage model in a commercial finite element code, Abequs [5] to study the response of GRP to projectile penetration. This work further examines the possibility of extending the CDM / hyperelasticity model to predict depth of penetration of a projectile into thick target plates at high velocities. In addition, the focus of the work is to validate the generality of the calibrated model parameters through comparison between the depth of penetration measured in ballistic tests and abequs simulations.

References:
[1] Liren Tsai, Fuping Yuan, Vikas Prakash, and Dattatraya P. Dandekar, “Shock compression behavior of a S2-glass fiber reinforced polymer composite,” Journal of Applied Physics, 105 (2009) 093526.
[2] Nicholas R. Scott, Arunachalam Rajendran, Matthew D. Nelms, and Vikas Prakash, “A New Woven Composite Constitutive Model Validated by Shock Wave Experiments, Accepted for publications in Journal of Applied Physics, 131, 2022 165905.
[3] ALE3D: Computational Manual Material Model, Developed at the Lawrence Livermore National Laboratory 7000 East Avenue • Livermore, CA 94550.
[4] James Fraser, “ABAQUS implementation of a hyperelastic damage model for glass-reinforced polymers under shock and impact loading,” A Thesis presented in partial fulfillment of requirements for the degree of Master of Science in the Department of Mechanical Engineering, The University of Mississippi, May 2022.
[5] Abaqus/Explicit, a special-purpose Finite-Element analyzer that employs explicit integration scheme to solve highly nonlinear systems with many complex contacts under transient loads. https://www.3ds.com/products-services/simulia/products/abaqus/