Portal 2D Frame - Dynamic EQ Ground Motion

Converted to openseespy by: Pavan Chigullapally
                      University of Auckland
                      Email: pchi893@aucklanduni.ac.nz

1. This is a simple model of an elastic portal frame with EQ ground motion and gravity loading. Here the structure is excited using uniform excitation load pattern

2. All units are in kip, inch, second

3. To run EQ ground-motion analysis, BM68elc.acc needs to be downloaded into the same directory)

4. The source code is shown below, which can be downloaded here.

5. The detailed problem description can be found here (example: 1b)

# -*- coding: utf-8 -*-
"""
Created on Mon Apr 22 17:29:26 2019

@author: pchi893
"""
# Converted to openseespy by: Pavan Chigullapally       
#                         University of Auckland  
#                         Email: pchi893@aucklanduni.ac.nz 
# Example 1b. portal frame in 2D
#This is a simple model of an elastic portal frame with EQ ground motion and gravity loading. Here the structure is excited using uniform excitation load pattern
# all units are in kip, inch, second
#To run EQ ground-motion analysis (BM68elc.acc needs to be downloaded into the same directory).
#the detailed problem description can be found here: http://opensees.berkeley.edu/wiki/index.php/Examples_Manual  (example: 1b)
# --------------------------------------------------------------------------------------------------
# elasticBeamColumn ELEMENT
#	OpenSees (Tcl) code by:	Silvia Mazzoni & Frank McKenna, 2006

#
#    ^Y
#    |
#    3_________(3)________4       __ 
#    |                                    |          | 
#    |                                    |          |
#    |                                    |          |
#  (1)                                 (2)       LCol
#    |                                    |          |
#    |                                    |          |
#    |                                    |          |
#  =1=                               =2=      _|_  -------->X
#    |----------LBeam------------|
#

# SET UP -----------------------------------------------------------------------------

import openseespy.opensees as op
#import the os module
import os
op.wipe()

#########################################################################################################################################################################

#########################################################################################################################################################################
op.model('basic', '-ndm', 2, '-ndf', 3) 

#to create a directory at specified path with name "Data"
#os.chdir('C:\\Opensees Python\\OpenseesPy examples')

#this will create the directory with name 'Data' and will update it when we rerun the analysis, otherwise we have to keep deleting the old 'Data' Folder
dir = "Data-1b"
if not os.path.exists(dir):
    os.makedirs(dir)

#this will create just 'Data' folder    
#os.mkdir("Data-1b")
    
#detect the current working directory
#path1 = os.getcwd()
#print(path1)

h = 432.0
w  =  504.0

op.node(1, 0.0, 0.0)
op.node(2, h, 0.0)
op.node(3, 0.0, w)
op.node(4, h, w)

op.fix(1, 1,1,1)
op.fix(2, 1,1,1)
op.fix(3, 0,0,0)
op.fix(4, 0,0,0)

op.mass(3, 5.18, 0.0, 0.0)
op.mass(4, 5.18, 0.0, 0.0)  

op.geomTransf('Linear', 1)
A = 3600000000.0
E = 4227.0
Iz = 1080000.0

A1 = 5760000000.0
Iz1 = 4423680.0
op.element('elasticBeamColumn', 1, 1, 3, A, E, Iz, 1)
op.element('elasticBeamColumn', 2, 2, 4, A, E, Iz, 1)
op.element('elasticBeamColumn', 3, 3, 4, A1, E, Iz1, 1)

op.recorder('Node', '-file', 'Data-1b/DFree.out','-time', '-node', 3,4, '-dof', 1,2,3, 'disp')
op.recorder('Node', '-file', 'Data-1b/DBase.out','-time', '-node', 1,2, '-dof', 1,2,3, 'disp')
op.recorder('Node', '-file', 'Data-1b/RBase.out','-time', '-node', 1,2, '-dof', 1,2,3, 'reaction')
#op.recorder('Drift', '-file', 'Data-1b/Drift.out','-time', '-node', 1, '-dof', 1,2,3, 'disp')
op.recorder('Element', '-file', 'Data-1b/FCol.out','-time', '-ele', 1,2, 'globalForce')
op.recorder('Element', '-file', 'Data-1b/DCol.out','-time', '-ele', 3, 'deformations')

#defining gravity loads
op.timeSeries('Linear', 1)
op.pattern('Plain', 1, 1)
op.eleLoad('-ele', 3, '-type', '-beamUniform', -7.94)

op.constraints('Plain')
op.numberer('Plain')
op.system('BandGeneral')
op.test('NormDispIncr', 1e-8, 6)
op.algorithm('Newton')
op.integrator('LoadControl', 0.1)
op.analysis('Static')
op.analyze(10)
    
op.loadConst('-time', 0.0)

#applying Dynamic Ground motion analysis
op.timeSeries('Path', 2, '-dt', 0.01, '-filePath', 'BM68elc.acc', '-factor', 1.0)
op.pattern('UniformExcitation', 2, 1, '-accel', 2) #how to give accelseriesTag?

eigen = op. eigen('-fullGenLapack', 1)
import math
power = math.pow(eigen[0], 0.5)
betaKcomm = 2 * (0.02/power)

op.rayleigh(0.0, 0.0, 0.0, betaKcomm)

op.wipeAnalysis()
op.constraints('Plain')
op.numberer('Plain')
op.system('BandGeneral')
op.test('NormDispIncr', 1e-8, 10)
op.algorithm('Newton')
op.integrator('Newmark', 0.5, 0.25)
op.analysis('Transient')
op.analyze(1000, 0.02)

u3 = op.nodeDisp(3, 1)
print("u2 = ", u3)

op.wipe()