0 kPa 0 kPa -500*heaviside((1.*t-0.)-(x-0.01))*heaviside((x+0.01)-(1.*t-0.)) 0 mm 1 0 0 0 mm 0 1 0 0 mm 0 0 1 0 MPa 0 MPa -500*heaviside((1.*t-0.1)-(x-0.01))*heaviside((x+0.01)-(1.*t-0.1))