Dynamic characterization of Roma Plastilina No. 1 from Drop Test and inverse analysis

Development of numerical model for ballistic resistance evaluation of combat helmet and experimental validation

“…For the cases requiring the simulation of clay, the coefficient of friction between the metal and Roma Plastilina No. 1 was equal to 0.193 according to [31].…”

“…The laminates constituting the plate and the helmet were meshed with C3D6 elements (6 node linear triangular prism) [31] with an ele ment size equal to 4 mm. The FE model of the plates is limited to 4 layers in order to reduce computational cost and increase computational effi ciency [18].…”

“…1 color grey green. Hernandez et al [31] carried out experimental tests in order to determine the material parameters associated with a given constitutive model. The characterization methodology posed as an in verse problem of Drop Test was formulated and solved as an optimiza tion procedure.…”

“…The characterization methodology posed as an in verse problem of Drop Test was formulated and solved as an optimiza tion procedure. Hernandez et al [31] proposed Eq. (4) in order to use Roma Plastilina No.…”

“…where k = 0.202 and is the material constant; n = 0.010 and is the strain hardening coefficient, m= 0.101 and is the strain rate sensitivity coeffi cient and _ ε 0 is the initial strain rate usually set to 1. Other material prop erties are: density ρ = 1529 kg/m 3 , Young Modulus E = 4.92 MPa and Poisson coefficient ν = 0.49 obtained from [31,37].…”