# --------------------------------------------------------------------------------------------------
# Example 1. portal frame in 2D
# static pushover analysis of Portal Frame, with gravity.
# all units are in kip, inch, second
# elasticBeamColumn ELEMENT
#		Silvia Mazzoni & Frank McKenna, 2006
#
#    ^Y
#    |
#    3_________(3)________4       __ 
#    |                                    |          | 
#    |                                    |          |
#    |                                    |          |
#  (1)                                 (2)       LCol
#    |                                    |          |
#    |                                    |          |
#    |                                    |          |
#  =1=                               =2=      _|_  -------->X
#    |----------LBeam------------|
#

# SET UP ----------------------------------------------------------------------------
wipe;						# clear opensees model
model basic -ndm 2 -ndf 3;				# 2 dimensions, 3 dof per node
file mkdir Data; 					# create data directory

# define GEOMETRY -------------------------------------------------------------
# nodal coordinates:
node 1 0 0;					# node#, X Y
node 2 504 0
node 3 0 432
node 4 504 432 

# Single point constraints -- Boundary Conditions
fix 1 1 1 1; 			# node DX DY RZ
fix 2 1 1 1; 			# node DX DY RZ
fix 3 0 0 0
fix 4 0 0 0

# nodal masses:
mass 3 5.18 0. 0.;					# node#, Mx My Mz, Mass=Weight/g.
mass 4 5.18 0. 0.

# Define ELEMENTS -------------------------------------------------------------
# define geometric transformation: performs a linear geometric transformation of beam stiffness and resisting force from the basic system to the global-coordinate system
geomTransf Linear 1;  		# associate a tag to transformation

# connectivity: (make A very large, 10e6 times its actual value)
element elasticBeamColumn 1 1 3 3600000000 4227 1080000 1;	# element elasticBeamColumn $eleTag $iNode $jNode $A $E $Iz $transfTag
element elasticBeamColumn 2 2 4 3600000000 4227 1080000 1
element elasticBeamColumn 3 3 4 5760000000 4227 4423680 1

# Define RECORDERS -------------------------------------------------------------
recorder Node -file Data/DFree.out -time -node 3 4 -dof 1 2 3 disp;			# displacements of free nodes
recorder Node -file Data/DBase.out -time -node 1 2 -dof 1 2 3 disp;			# displacements of support nodes
recorder Node -file Data/RBase.out -time -node 1 2 -dof 1 2 3 reaction;		# support reaction
recorder Drift -file Data/Drift.out -time -iNode 1 2 -jNode 3 4 -dof 1  -perpDirn 2 ;	# lateral drift
recorder Element -file Data/FCol.out -time -ele 1 2 globalForce;			# element forces -- column
recorder Element -file Data/FBeam.out -time -ele 3 globalForce;			# element forces -- beam

# define GRAVITY -------------------------------------------------------------
pattern Plain 1 Linear {
   eleLoad -ele 3 -type -beamUniform -7.94 ; # distributed superstructure-weight on beam
}




constraints Plain;     				# how it handles boundary conditions
numberer Plain;					# renumber dof's to minimize band-width (optimization), if you want to
system BandGeneral;				# how to store and solve the system of equations in the analysis
test NormDispIncr 1.0e-8 6 ; 				# determine if convergence has been achieved at the end of an iteration step
algorithm Newton;					# use Newton's solution algorithm: updates tangent stiffness at every iteration
integrator LoadControl 0.1;				# determine the next time step for an analysis, # apply gravity in 10 steps
analysis Static					# define type of analysis static or transient
analyze 10;					# perform gravity analysis
loadConst -time 0.0;				# hold gravity constant and restart time

# define LATERAL load -------------------------------------------------------------
# Lateral load pattern
pattern Plain 2 Linear {
	load 3 2000. 0.0 0.0;			# node#, FX FY MZ -- representative lateral load at top nodes
	load 4 2000. 0.0 0.0;			# place 1/2 of the weight for each node to get shear coefficient
}

# pushover: diplacement controlled static analysis
integrator DisplacementControl 3 1 0.1;		# switch to displacement control, for node 11, dof 1, 0.1 increment
analyze 100;					# apply 100 steps of pushover analysis to a displacement of 10

puts "Done!"