PSI - Issue 72

Gusti Kid Faiq Syah et al. / Procedia Structural Integrity 72 (2025) 401–408

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maximum speed of 200 m/s. A camera was used to observe the value of the residual velocity. The simulation ends at 8ms because the bullet has successfully penetrated the target plate within that specified time.

Figure 2. Boundary condition constraints.

Figure 3. Plate mesh zones.

3. Results and Discussion The power law plasticity material model was used to define the material behavior of aluminum plates using the LS-DYNA/Explicit finite component code. This is an isotropic plasticity model with rate effects, which uses a power law hardening rule. A material's work hardening exponent, or n -value measures how quickly it gains strength when deformed. The n-value can be obtained from the slope of the true stress versus true strain curve in a tensile test plotted on a logarithmic scale. The relationship between stress and strain can be expressed in Equation 1. The demonstration consolidates the material flow using the mass density, Young’s modulus, Poisson’s ratio, strength coefficient, and hardening exponent due to impacts. The yield stress ( ) of the Power Law, theplasticity model, is expressed in Equation 2. = (1) = ( + ̅ ) (2) where ε yp is the elastic strain to yield and ε̅ p is the effective plastic strain (logarithmic). The power law plasticity model assumes that the k is a function of the strain rate ε .