Are there any examples of a drop test simulation in ANSYS LS-DYNA without
using the Drop Test Module (DTM) ?


Yes, please see the ANSYS LS-DYNA 8.1 example below of a bouncing ball.



fini
/clear

/title, Drop Test Simulation of a Bouncing Ball in ANSYS LS-DYNA 8.1

radius=8.0 ! sphere radius (inches) with origin at (0,0,0)
num_elem=8 ! number of elements in radial direction (must be even number)
drop_ht=30.0 ! drop height (inches) from top of base to bottom of ball
start_ht=1.0 ! height (inches) above base at start of analysis (use EDVEL)
termtime=2.00 ! solution time (seconds) -> account for initial velocity, ...

/plopts,info,1
/pnum,volu,1
/view,,1,2,3
/dscale,,1

/RGB,INDEX,100,100,100, 0
/RGB,INDEX, 80, 80, 80,13
/RGB,INDEX, 60, 60, 60,14
/RGB,INDEX, 0, 0, 0,15

/prep7
grav_acc=386.4 ! acceleration due to gravity (g), in/sec^2

et,1,SOLID164
r,1
mp,ex,1,30.0e6 ! elastic modulus, psi
mp,nuxy,1,0.30 ! Poisson's ratio, unitless
mp,dens,1,100.0*0.283/grav_acc ! 10 X mass density, lbf-sec^2/in^4
edmp,hgls,1,5 ! stiffness form of hourglass control

et,2,SOLID164
r,2
mp,ex,2,30.0e6 ! elastic modulus, psi
mp,nuxy,2,0.30 ! Poisson's ratio, unitless
mp,dens,2,100.0*0.283/grav_acc ! 10 X mass density, lbf-sec^2/in^4
edmp,rigid,2,7,7 ! fixed rigid body (target surface)

sph4,0.0,0.0,radius

vsbw,all
wprota,0,90,0
vsbw,all
wprota,0,0,90
vsbw,all

wpcsys,-1,0
wpstyle
vglue,all
numcmp,kp
numcmp,line
numcmp,area
numcmp,volu
vplot
/wait,1

mat,1
type,1
real,1
lesize,all,,,num_elem ! number of elements along radii (must be even #)
vmesh,all ! mesh bouncing ball (sphere)
cm,nball,node
cm,eball,elem
eplot

xdim=3*radius
ydim1=-2*radius-start_ht
ydim2=-radius-start_ht
zdim=3*radius

vsel,none
block,-xdim,xdim,ydim1,ydim2,-zdim,zdim
mat,2
type,2
real,2
nsel,none
esel,none
esize,,1 ! single element for base
vmesh,all ! rigid body (target surface)
vsel,all
cm,nblock,node
cm,eblock,elem
nsel,all
esel,all
/pnum,type,1
/num,1
eplot

! Calculate initial velocity for (drop height - start height) ...

init_vel = (2.0*grav_acc*(drop_ht-start_ht))**0.5

edvel,vgen,nball,0,-init_vel,0 ! initial velocity near impact ...

edcgen,ag ! automatic general contact

edpart,create
eddamp,all,,0.10 ! 10% alpha (mass) damping
eddamp,1,,1.0e-4 ! beta (stiffness) damping
fini

/solu
time,termtime
edrst,50
edhtime,500
edhist,nball
edenergy,1,1,1,1
edout,glstat
!!! edopt,add,,both

*dim,etime,,2,1,1
*dim,base_acc,,2,1,1
etime(1)=0.0,1.1*termtime
base_acc(1)=grav_acc,grav_acc
edload,add,acly,,nball,etime(1),base_acc(1)

nsel,s,loc,x,0 ! prevent round-off from becoming a problem ...
nsel,r,loc,z,0
d,all,ux,0.0
d,all,uz,0.0
nsel,all

save
solve
save
fini

/post26
file,,his
numvar,200

ntrack=node(0.0,-radius,0.0) ! identify node to track in POST26
nsol,2,ntrack,a,y,ay
nsol,3,ntrack,v,y,vy
nsol,4,ntrack,u,y,uy
store,merge

plvar,2
/wait,3
plvar,3
/wait,3
plvar,4

prvar,2,3,4

/eof


PARAMETER RADIUS = 8.000000

PARAMETER NUM_ELEM = 8.000000

PARAMETER DROP_HT = 30.00000

PARAMETER START_HT = 1.000000

PARAMETER TERMTIME = 2.000000

PARAMETER GRAV_ACC = 386.4000

PARAMETER INIT_VEL = 149.7037

Apply Initial Velocity to node component: NBALL
Translation : Vx = 0.0000 Vy = -149.70 Vz = 0.0000
Rotation : Omega = 0.0000
Rotation Axis: Xc = 0.0000 Yc = 0.0000 Zc = 0.0000
Ax = 0.0000 Ay = 0.0000 Az = 0.0000

Note:

The initial velocity was rounded from -149.70 to 150. when written to the .K file.

Also, the ball started one inch above the target surface, so the maximum downward
displacement is -1.0", and for a drop height of 30.0", the maximum displacement
upward would then be 29.0", assuming there was no damping.

With an initial downward displacement of -1.08", the ball slightly penetrates the
target surface (by roughly 0.08"), and then bounces back up to a maximum height of
28.02". Therefore, the total travel distance is roughly 29", which is one inch
less than that which would occur if there was no damping. However, there is 10%
alpha damping applied, which decays the maximum height on each bounce. The next
maximum height is 27.3" (26.3 - -1.0), followed by a maximum height of 25.7"...


***** ANSYS POST26 VARIABLE LISTING *****


TIME 10 AY 10 VY 10 UY
ay vy uy
0.0000 -386.400 -150.000 0.00000
0.39946E-02 -386.473 -151.483 -0.602174
0.79890E-02 495817. -128.643 -1.07669
0.11983E-01 254152. 73.0662 -1.05661
0.15983E-01 415649. 162.023 -0.557684
0.19998E-01 271148. 124.920 0.402851E-01
0.23995E-01 -508337. 120.341 0.644607
0.27994E-01 149839. 151.773 1.22387
0.31988E-01 -485978. 151.394 1.80565
0.35990E-01 -144399. 176.0032.37978
0.39985E-01 28619.4 189.467 2.94057
0.43981E-01 301016. 133.528 3.49798
0.47995E-01 66472.7 155.318 4.05911
0.51989E-01 449028. 130.780 4.59902
0.55983E-01 -56532.4 83.6180 5.14617
0.59997E-01 -214452. 118.468 5.68576
0.63991E-01 -232744. 135.495 6.20972
0.67986E-01 -141805. 135.840 6.73274
. . . .
. . . .
. . . .
0.38799 11922.5 21.6890 28.0049
0. . .
. . . .
. . . .


This input file (sphere.inp) is also attached to this record (Onyx Solution 335740) ...

.





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