Source code for pysph.sph.solid_mech.hvi

"""
Equations for the High Velocity Impact Problems
###############################################
"""

from math import sqrt
from pysph.sph.equation import Equation

[docs]class VonMisesPlasticity2D(Equation): def __init__(self, dest, sources, flow_stress): self.flow_stress2 = flow_stress*flow_stress self.factor = sqrt( 2.0/3.0 )*flow_stress super(VonMisesPlasticity2D,self).__init__(dest, sources)
[docs] def loop(self, d_idx, d_s00, d_s01, d_s11): s00a = d_s00[d_idx] s01a = d_s01[d_idx] s10a = d_s01[d_idx] s11a = d_s11[d_idx] J = s00a* s00a + 2.0 * s01a*s10a + s11a*s11a scale = 1.0 if (J > 2.0/3.0 * self.flow_stress2): scale = self.factor/sqrt(J) # store the stresses d_s00[d_idx] = scale * s00a d_s01[d_idx] = scale * s01a d_s11[d_idx] = scale * s11a
[docs]class MieGruneisenEOS(Equation): def __init__(self, dest, sources, gamma,r0, c0, S): self.gamma = gamma self.r0 = r0 self.c0 = c0 self.S = S self.a0 = a0 = r0 * c0 * c0 self.b0 = a0 * ( 1 + 2.0*(S - 1.0) ) self.c0 = a0 * ( 2*(S - 1.0) + 3*(S - 1.0)*(S - 1.0) ) super(MieGruneisenEOS, self).__init__(dest, sources)
[docs] def loop(self, d_idx, d_p, d_rho, d_e): rhoa = d_rho[d_idx] ea = d_e[d_idx] gamma = self.gamma ratio = rhoa/self.r0 - 1.0 ratio2 = ratio * ratio PH = self.a0 * ratio if ratio > 0: PH = PH + ratio2 * (self.b0 + self.c0*ratio) d_p[d_idx] = (1. - 0.5*gamma*ratio) * PH + rhoa * ea * gamma