*HEADING 1D transient wave propagation, acoustic medium, incident wave load and incident wave reflection, planar and defined through pressure amplitude ** *PREPRINT,ECHO=NO,HISTORY=yes,MODEL=YES *NODE,NSET=BRICK 1,-0.5,-0.5 2,0.5,-0.5 3,0.5,0.5 4,-0.5,0.5 5,-0.5,-0.5,-1. 6,0.5,-0.5,-1. 7,0.5,0.5,-1. 8,-0.5,0.5,-1. *NSET,NSET=PLATE 1,2,3,4 *ELEMENT,TYPE=AC3D8,ELSET=ACOUSTIC 1,1,4,3,2,5,8,7,6, ************************** *SURFACE,NAME=ABSORB 1,S2 *SURFACE,NAME=IW_LOAD 1,S1 ************************** *SOLID SECTION,MATERIAL=AIR,ELSET=ACOUSTIC *MATERIAL,NAME=AIR *DENSITY 1., *ACOUSTIC MEDIUM,BULK MODULUS 0.16E6, ************************** *INCIDENT WAVE PROPERTY,NAME=IWPROP,TYPE=PLANE 0.0,0.0,0. 0.0,10.0,10. *INCIDENTWAVE FLUID PROPERTY 0.16E6, 1. *AMPLITUDE,DEFINITION=periodic,NAME=PRESSUREVTIMESINE 1,350.0,0.0,0.0 0.0,1.0 *AMPLITUDE,DEFINITION=tabular,NAME=PRESSUREVTIMESTEP 0.0,0.0,0.01,1.0 ************************** *STEP,INC=1000 *DYNAMIC,ALPHA=0.0 0.001,0.06 ** *SIMPEDANCE,non=pl ABSORB, *INCIDENTWAVE,PRESSUREAMPLITUDE=PRESSUREVTIMESTEP,PROPERTY=IWPROP IW_LOAD,1.0 ** *INCIDENT WAVE REFLECTION 20.0, 0,-1,0, -1.0 ** *OUTPUT,FIELD,FREQ=999 *NODE OUTPUT,NSET=BRICK POR, *OUTPUT,HISTORY,FREQ=1 *NODE OUTPUT,NSET=PLATE POR, ** *END STEP *STEP,INC=1000 *DYNAMIC,ALPHA=0.0 0.001,0.09 ** *SIMPEDANCE,non=pl ABSORB, *INCIDENTWAVE,PRESSUREAMPLITUDE=PRESSUREVTIMESTEP,PROPERTY=IWPROP IW_LOAD,-3.0 ** *INCIDENT WAVE REFLECTION 15.0,0,-1,0, -1.0 ** *OUTPUT,FIELD,FREQ=999 *NODE OUTPUT,NSET=BRICK POR, *OUTPUT,HISTORY,FREQ=1 *NODE OUTPUT,NSET=PLATE POR, ** *END STEP