Data Files for “Rolling Resistance Linear Contact Model: Single Ball on a Flat Surface” Problem

make_system.p2dat

;===========================================================================
; fname: make_system.p2dat
;===========================================================================
model new
model title ...
'Rolling Resistance Linear Contact Model: Single Ball on a Flat Surface'

; define domain extent and boundary conditions
model domain extent -1.0 1.0 -1e-1 2e-1 condition destroy

; set the defaults slots of the CMAT to use the rrlinear contact model
contact cmat default model rrlinear ...
                            method deformability emod 1e7 kratio 1.0 ...
                            property dp_nratio 0.2 dp_mode 3

; create the system and settle under gravity
wall generate plane
ball create radius 5e-3 position-y 5e-3
ball attribute density 2500.0
model gravity 9.81
model solve

; set up history monitoring
model mechanical time-total 0.0
model orientation-tracking on
model energy mechanical on
history interval  1
model history name "1" mechanical time-total
model history name "2" mechanical energy energy-kinetic
model history name "3" mechanical energy energy-slip
model history name "4" mechanical energy energy-rrslip
model history name "5" mechanical energy energy-dashpot
model history name "6" mechanical energy energy-strain
model history name "7" mechanical energy energy-rrstrain
ball history name "11" position-x id 1
ball history name "12" spin id 1
ball history name "13" velocity-x id 1
ball attribute velocity-x 1.0
model save 'system-ini'
program return
;===========================================================================
; eof: make_system.p2dat

test_system.p2dat

;===========================================================================
; fname: test_system.p2dat
;===========================================================================

; CASE HORIZONTAL-0: no rolling friction
model restore 'system-ini'
contact property fric 0.8
model solve time 1.5
model save 'final-horizontal-0.p2sav'

; CASE HORIZONTAL-1: friction and rolling friction
model restore 'system-ini'
contact property fric 0.8 rr_fric 0.1
model solve time 1.5
model save 'final-horizontal-1.p2sav'

; CASE HORIZONTAL-2: friction, rolling friction and damping 
model restore 'system-ini'
contact property fric 0.8 rr_fric 0.1 dp_sratio 0.2
model solve time 1.5
model save 'final-horizontal-2.p2sav'

; CASE INCLINED-1: rolling friction below tangent of the slope inclination
model restore 'system-ini'
[theta = math.degrad*10.0]
model gravity [-9.81*math.sin(theta)] [-9.81*math.cos(theta)]
contact property fric 0.8 rr_fric 0.1 dp_sratio 0.2
model solve time 1.5
model save 'final-inclined-1.p2sav'

; CASE INCLINED-2: rolling friction equal to tangent of the slope inclination
model restore 'system-ini'
[theta = math.degrad*10.0]
model gravity [-9.81*math.sin(theta)] [-9.81*math.cos(theta)] 
contact property fric 0.8 rr_fric [math.tan(theta)] dp_sratio 0.2
model solve time 1.5
model save 'final-inclined-2.p2sav'
program return
;=============================================================================
; eof: test_system.p2dat
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