# $Header: /var/cvs/mbdyn/mbdyn/mbdyn-web/documentation/examples/rigidpendulum,v 1.3 2008/11/05 21:07:42 masarati Exp $

begin: data;
	integrator: multistep; # the default
end: data;

begin: multistep;
	initial time: 0.;
	final time: 1.;
	time step: 1.e-3;

	max iterations: 10;
	tolerance: 1.e-6;
end: multistep;

begin: control data;
	structural nodes: 
		+1    # node in the constraint
		+1    # node in the mass
		+2    # distance: mass+ground
	;
	rigid bodies:
		+1    # node in the constraint
		+1    # node in the mass
		+1    # distance: mass
	;
	joints:
		+1    # node in the constraint: revolute
		+1    # node in the mass: revolute
		+2    # distance: distance+ground
	;
	gravity;
end: control data;

set: integer Pendulum = 1;
set: integer Mass = 2;
set: real M = 1.;
set: real L = .5;
set: real Omega0 = .2;

reference: Pendulum,
	reference, global, null,
	reference, global, eye,
	reference, global, null,
	reference, global, 0., Omega0, 0.;
reference: Mass,
	reference, Pendulum, 0., 0., -L,
	reference, Pendulum, eye,
	reference, Pendulum, null,
	reference, Pendulum, null;

begin: nodes;
	structural: 1000+Pendulum, dynamic, 
		reference, Pendulum, null, 
		reference, Pendulum, eye, 
		reference, Pendulum, null, 
		reference, Pendulum, null;

	structural: 2000+Mass, dynamic,
		reference, Mass, null,
		reference, Mass, eye,
		reference, Mass, null,
		reference, Mass, null;

	# no dynamic dofs (it will be fully grounded)
	structural: 3000+Pendulum, static, 
		reference, Pendulum, null,
		reference, Pendulum, eye,
		reference, Pendulum, null,
		reference, global, null;
	# "global" means no angular velocity!

	structural: 3000+Mass, dynamic,
		reference, Mass, null,
		reference, Mass, eye,
		reference, Mass, null,
		reference, global, null;
	# "global" means no angular velocity!
end: nodes;

begin: elements;
	body: 1000+Mass, 1000+Pendulum, 
		M,
		reference, Mass, null,
		# the problem is non-singular, despite the null inertia,
		# because of the constraint that does not allow rotation
		null;
	joint: 1000+Mass, revolute pin,
		1000+Pendulum, 
			reference, Pendulum, null,
			hinge, reference, Pendulum, 
				1, 1.,0.,0., 3, 0.,1.,0.,
		reference, Pendulum, null,
		hinge, reference, Pendulum, 
			1, 1.,0.,0., 3, 0.,1.,0.;

	body: 2000+Mass, 2000+Mass,
		M,
		reference, Mass, null,
		# the problem is non-singular, despite the null inertia,
		# because of the constraint that does not allow rotation
		null;
	joint: 2000+Mass, revolute pin,
		2000+Mass, 
			reference, Pendulum, null,
			hinge, reference, Pendulum, 
				1, 1.,0.,0., 3, 0.,1.,0.,
		reference, Pendulum, null,
		hinge, reference, Pendulum, 
			1, 1.,0.,0., 3, 0.,1.,0.;

	body: 3000+Mass, 3000+Mass,
		M,
		reference, Mass, null,
		# otherwise the problem would be singular ...
		eye;
	joint: 3000+Pendulum, clamp,
		3000+Pendulum, node, node;
	joint: 3000+Mass, distance,
		3000+Pendulum,
		3000+Mass,
		const, L;

	gravity: 0., 0., -1., const, 9.81;
end: elements;