Next ‘’------------------------------------------------------------------------ ‘’-- compute viscous drag (aka friction) ‘’-d = 1.2 ‘’ drag coefficient for iprt = 0 to nprt - 1 a fraction of velocity ‘’-- drag force ( F = - d * v ) force = agaist iprt )( PRT_A ), f ) ‘’-- accumulate forces prts( iprt )( PRT_A ) = vector_add( prts( f = vector_scale( prts( iprt )( PRT_V ), -d ) a = vector_new( 0.0, 0.0, 0.0 ) ‘’-- zero mass -> zero acceleration/force end if prts( iprt )( PRT_V ) = vector_add( prts( iprt )( PRT_V ), a ) next --------- ‘’----------------------------------------------------------------- volume ‘’-- some safety rules against explosions ‘’-- or pseudo inelastic collision ‘’-- ie don’t allow particles outside a maximum ‘’-Dim xmin,ymin,zmin Dim xmax,ymax,zmax Dim reset next ‘delta = u or v (at least) ‘’-- a bounding cube size --------- ‘’----------------------------------------------------------------- delta=nx Rhino.AddLayer “Lines”, RGB(225, 100, 20) Rhino.LayerVisible “Lines”, False vbred ) ‘’-- draw forces ‘ for iprt = 0 to nprt - 1 ‘ p = prts( iprt )( PRT_P ) ‘ f = prts( iprt )( PRT_A ) ‘ l = rhino.addline( p, vector_add( p, f ) ) ‘ if( not isnull( l ) ) then call rhino.objectcolor( l, --------- ‘’----------------------------------------------------------------- for iprt = 0 to nprt - 1 ‘ next ‘’-- integrate positions using an euler solver ‘’-- this induces errors for large time steps! ‘’-- for iprt = 0 to nprt - 1 Dim dt dt = 0.01 ‘’-- time step p_old + v ) iprt )( PRT_P ), v ) ‘’-- position ( p_new = p_old + dp/dt = v = vector_scale( prts( iprt )( PRT_V ), dt ) prts( iprt )( PRT_P ) = vector_add( prts( ‘’-- velocity ( v_new = v_old + dv/dt = v_old + a = v_old + f / m ) if( prts( iprt )( PRT_M ) <> 0 ) then a = vector_scale( prts( iprt )( PRT_A ), dt / prts( iprt )( PRT_M ) ) else 192 xmin = -delta: xmax = delta ymin = -delta: ymax = delta zmin = -delta: zmax = delta ‘’-- on explosion reset velocity reset = false ‘’-- xmin < position.x < xmax if( prts( iprt )( PRT_P )( VERTEX_X ) < xmin ) then prts( iprt )( PRT_P )( VERTEX_X ) = xmin reset = true elseif( prts( iprt )( PRT_P )( VERTEX_X ) > xmax ) then prts( iprt )( PRT_P )( VERTEX_X ) = xmax reset = true end if ‘’-- ymin < position.y < ymax if( prts( iprt )( PRT_P )( VERTEX_Y ) < ymin ) then prts( iprt )( PRT_P )( VERTEX_Y ) = ymin reset = true elseif( prts( iprt )( PRT_P )( VERTEX_Y ) > ymax ) then prts( iprt )( PRT_P )( VERTEX_Y ) = ymax end if reset = true ‘’-- zmin < position.z < zmax if( prts( iprt )( PRT_P )( VERTEX_Z ) < zmin ) then prts( iprt )( PRT_P )( VERTEX_Z ) = zmin reset = true elseif( prts( iprt )( PRT_P )( VERTEX_Z ) > zmax ) then prts( iprt )( PRT_P )( VERTEX_Z ) = zmax reset = True end if ‘’-- exploded! if( reset ) then prts( iprt )( PRT_V )( VERTEX_X ) = 0.0 prts( iprt )( PRT_V )( VERTEX_Y ) = 0.0 prts( iprt )( PRT_V )( VERTEX_Z ) = 0.0 end if End If Next ‘’-------------------------------------------------------------------------}}} ‘’-- unblock screen rhino.enableredraw True next --------- ‘’----------------------------------------------------------------- rhino.deleteobject edgs( iedg )( EDG_O ) si = edgs( iedg )( EDG_S ) ei = edgs( iedg )( EDG_E ) sp = prts( si ) ep = prts( ei ) edgs( iedg )( EDG_O ) = rhino. addline( sp( PRT_P ), ep( PRT_P ) ) Rhino.ObjectLayer edgs( iedg ) ( EDG_O ), “Lines” Next ‘’-- ok show! rhino.enableredraw True Rhino.AddLayer “Supports”, RGB(255, 0, 0) Rhino.AddLayer “Forces”, RGB(0, 255,0) If( iteration Mod 10 = 0 ) Then ‘’-- graphics time! rhino.enableredraw False ‘’-- update particles and control points of grid(just update) for iprt = 0 to nprt - 1 rhino.pointcoordinates prts( iprt )( PRT_O ), prts( iprt)( PRT_P ) ReDim Preserve newpgrid(iprt) newpgrid(ipr t)=pr ts(ipr t) (PRT_P) Next ‘’--delete previous grid surface and redraw it with new coordinates rhino.deleteobject gridsurface gridsurface=Rhino.AddNurbsSurface (gridcount, newpgrid, arrKnotU, arrKnotV, arrDegree, arrWeights) ‘’-- update edges (delete and redraw) For iedg = 0 To nedg - 1 For i=0 To ubound(fixed_points) Rhino.ObjectLayer fixed_points(i), “Supports” Next For i=0 To ubound(ext_f_points) Rhino.ObjectLayer ext_f_points(i), “Forces” Next Rhino.AddLayer “Grid Surface”, RGB(255, 255, 255) Rhino.ObjectLayer gridsurface, “Grid Surface” Rhino.LayerVisible “Grid Surface”, True Dim pointsA(),pointsB() Dim i1,i2 Dim half_limit half_limit=((ubound(newpgrid)+1)/2)-1 For i1=0 To half_limit ReDim Preserve pointsA(i1) pointsA(i1)=newpgrid(i1) Next

Fibre Composite Adaptive Systems