rolling without slip

[kermher]

Can somebody give me a link, or a tutorial to learn how to make a cylinder roll without slip on a giant box. (I just search how to do : joint gear, wheel and tire ..).
We have already tried out what could work, but there is always errors in simulation. That's why we are looking for the right way to do it.

Ps: We are french students and beginners with msc adams view, so please be very complete and simple in your answers.

Thanks a lot.

 

[jslat]

A GCON is the easiest/most generic way to implement this.


Jesper Slattengren

http://www.prattmiller.com

 

[GregLocock]

I set up a simple roller dropping on to an inclined block.

Worked first time.

Here's the contact statement

! adams_view_name='CONTACT_1'
CONTACT/1, IGEOM = 2, JGEOM = 1, IMPACT, STIFFNESS = 1.0E+005, DAMPING = 10
, DMAX = 0.1, EXPONENT = 2.2, COULOMB_FRICTION = ON, MU_STATIC = 0.3
, MU_DYNAMIC = 0.1, STICTION_TRANSITION_VELOCITY = 100
, FRICTION_TRANSITION_VELOCITY = 1000
!

The roller hits the ramp, bounces, and then rolls down the ramp.

here's the entire adm

ADAMS/View model name: model_1
!
!-------------------------------- SYSTEM UNITS ---------------------------------
!
UNITS/FORCE = NEWTON, MASS = KILOGRAM, LENGTH = MILLIMETER, TIME = SECOND
!
!----------------------------------- PARTS -------------------------------------
!
!----------------------------------- Ground ------------------------------------
!
! adams_view_name='ground'
PART/1, GROUND
!
! adams_view_name='MARKER_9'
MARKER/9, PART = 1, QP = -150, -300, 0
!
!------------------------------------ Part -------------------------------------
!
! adams_view_name='PART_2'
PART/2, REULER = 30D, 0D, 0D, MASS = 608.478, CM = 5, IP = 2.953653623E+007
, 2.598708125E+007, 1.267662498E+007
!
! adams_view_name='MARKER_1'
MARKER/1, PART = 2, QP = -300, 50, 0
!
! adams_view_name='cm'
MARKER/5, PART = 2, QP = 25, -100, 200, REULER = 90D, 90.00000016D, 359.9999998D
!
! adams_view_name='MARKER_8'
MARKER/8, PART = 2, QP = -279.9038106, -184.8076211, 0, REULER = 330D, 0D, 0D
!
! adams_view_name='BOX_1'
GRAPHICS/1, BOX, CORNER = 1, X = 650, Y = -300, Z = 400
!
!------------------------------------ Part -------------------------------------
!
! adams_view_name='PART_3'
PART/3, QG = 0, 110, 960, REULER = 90D, 90D, 270D, MASS = 10.33912869, CM = 7
, IP = 81178.31507, 81178.31507, 7269.699857
!
! adams_view_name='MARKER_6'
MARKER/6, PART = 3, QP = 600, 150, 0, REULER = 90D, 90D, 0D
!
! adams_view_name='cm'
MARKER/7, PART = 3, QP = 750, 150, 0, REULER = 90D, 90D, 0D
!
! adams_view_name='CYLINDER_2'
GRAPHICS/2, CYLINDER, CM = 6, LENGTH = 300, RADIUS = 37.5
!
!---------------------------------- CONTACTS -----------------------------------
!
! adams_view_name='CONTACT_1'
CONTACT/1, IGEOM = 2, JGEOM = 1, IMPACT, STIFFNESS = 1.0E+005, DAMPING = 10
, DMAX = 0.1, EXPONENT = 2.2, COULOMB_FRICTION = ON, MU_STATIC = 0.3
, MU_DYNAMIC = 0.1, STICTION_TRANSITION_VELOCITY = 100
, FRICTION_TRANSITION_VELOCITY = 1000
!
!------------------------------ DYNAMIC GRAPHICS -------------------------------
!
!-------------------------------- CONSTRAINTS ----------------------------------
!
! adams_view_name='JOINT_1'
JOINT/1, FIXED, I = 8, J = 9
!
!------------------------- GRAVITATIONAL ACCELERATION --------------------------
!
ACCGRAV/JGRAV = -9806.65
!
!----------------------------- ANALYSIS SETTINGS -------------------------------
!
OUTPUT/REQSAVE, GRSAVE
!
RESULTS/XRF
!
END


Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[GregLocock]

However, I agree with jslat, if you cannot have any slip then you'll have to set up a gear coupler. That's covered in the tutorials.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[jslat]

Actually, a GCON is more generic than the coupler. And way cooler. But it needs the C++solver.
Here is a small testmodel (that I already posted on the MSC forum):

ADAMS/View model name: model_1
!
!-------------------------------- SYSTEM UNITS ---------------------------------
!
UNITS/
, FORCE = NEWTON
, MASS = KILOGRAM
, LENGTH = MILLIMETER
, TIME = SECOND
!
!----------------------------------- PARTS -------------------------------------
!
!----------------------------------- Ground ------------------------------------
!
! adams_view_name='ground'
PART/1
, GROUND
!
! adams_view_name='MARKER_1'
MARKER/1
, PART = 1
, QP = -550, 0, 0
!
! adams_view_name='BOX_1'
GRAPHICS/1
, BOX
, CORNER = 1
, X = 1150
, Y = -250
, Z = 500
!
!------------------------------------ Part -------------------------------------
!
! adams_view_name='PART_2'
PART/2
, MASS = 24.50756429
, CM = 3
, IP = 1.225378215E+005, 81691.88097, 81691.88097
, VX = 50
!
! adams_view_name='MARKER_2'
MARKER/2
, PART = 2
, QP = 0, 100, 0
!
! adams_view_name='cm'
MARKER/3
, PART = 2
, QP = 0, 100, 50
, REULER = 270D, 90D, 90D
!
! adams_view_name='CYLINDER_2'
GRAPHICS/2
, CYLINDER
, CM = 2
, LENGTH = 100
, RADIUS = 100
!
!-------------------------------- CONSTRAINTS ----------------------------------
!
! adams_view_name='GCON_1'
GCON/1
, I = 3
, FUNCTION = DY(3, 1, 1)-100
!
! adams_view_name='GCON_2'
GCON/2
, I = 3
, FUNCTION = VX(3, 1, 1)+100*WZ(3, 1, 1)
!
!------------------------- GRAVITATIONAL ACCELERATION --------------------------
!
ACCGRAV/
, JGRAV = -9806.65
!
!----------------------------- ANALYSIS SETTINGS -------------------------------
!
OUTPUT/
, REQSAVE
, GRSAVE
!
RESULTS/
, XRF
!
END




Jesper Slattengren

http://www.prattmiller.com