Reinforced Concrete Shear Wall with Special Boundary ElementsΒΆ

  1. The original code was written for OpenSees Tcl by Lu X.Z. et al. (2015) <http://www.luxinzheng.net/download/OpenSEES/Examples_of_NLDKGQ_element.htm>.

  2. The source code is converted to OpenSeesPy by Anurag Upadhyay from University of Utah.

  3. Four node shell elements with LayeredShell sections are used to model the shear wall.

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

  5. Download the cyclic test load input and output files, RCshearwall_Load_input, RCshearwall_TestOutput.

  6. The details of the shear wall specimen are shown in the figure below, along with the finite element mesh.

  7. Run the source code and you should see the cyclic test plot overlaid by a pushover curve, shown at the end.

../_images/RCshearwall_Specimen-Mesh.png
  1
  2# Converted to openseespy by: Anurag Upadhyay, University of Utah.
  3# Units: N and m to follow the originally published code.
  4
  5from openseespy.opensees import *
  6
  7import numpy as np
  8import matplotlib.pyplot as plt
  9import os
 10import math
 11
 12pi = 3.1415
 13
 14AnalysisType = "Pushover" # Cyclic   Pushover   Gravity
 15
 16wipe()
 17
 18model('basic','-ndm',3,'-ndf',6)
 19
 20###################################
 21## Define Material
 22###################################
 23
 24# Define PSUMAT and convert it to plane stress material
 25nDMaterial('PlaneStressUserMaterial',1,40,7,20.7e6,2.07e6,-4.14e6,-0.002,-0.01,0.001,0.3)
 26nDMaterial('PlateFromPlaneStress',4,1,1.25e10)
 27
 28# Define material for rebar
 29uniaxialMaterial('Steel02',7,379e6,202.7e9,0.01,18.5,0.925,0.15)
 30uniaxialMaterial('Steel02',8,392e6,200.6e9,0.01,18.5,0.925,0.15)
 31
 32# Convert rebar material to plane stress/plate rebar 
 33# Angle 0 is for vertical rebar and 90 is for horizontal rebar
 34nDMaterial('PlateRebar',9,7,90.0)
 35nDMaterial('PlateRebar',10,8,90.0)
 36nDMaterial('PlateRebar',11,8,0.0)
 37
 38# Define LayeredShell sections. Section 1 is used for the special boundary elements and section 2 is used for the unconfined interior wall portion
 39section('LayeredShell',1,10,4,0.0125,11,0.0002403,11,0.0003676,4,0.024696,4,0.024696,4,0.024696,4,0.024696,11,0.0003676,11,0.0002403,4,0.0125)
 40section('LayeredShell',2,8,4,0.0125,11,0.0002403,10,0.0002356,4,0.0495241,4,0.0495241,10,0.0002356,11,0.0002403,4,0.0125)
 41
 42# ##################
 43# NODES
 44# ##################
 45#define nodes
 46node(1,0.0,0,0)
 47node(2,0.2,0,0)
 48node(3,0.5,0,0)
 49node(4,0.8,0,0)
 50node(5,1.0,0,0)
 51
 52node(6,0.0,0.2,0)
 53node(7,0.2,0.2,0)
 54node(8,0.5,0.2,0)
 55node(9,0.8,0.2,0)
 56node(10,1.0,0.2,0)
 57
 58node(11,0.0,0.4,0)
 59node(12,0.2,0.4,0)
 60node(13,0.5,0.4,0)
 61node(14,0.8,0.4,0)
 62node(15,1.0,0.4,0)
 63
 64node(16,0.0,0.6,0)
 65node(17,0.2,0.6,0)
 66node(18,0.5,0.6,0)
 67node(19,0.8,0.6,0)
 68node(20,1.0,0.6,0)
 69
 70node(21,0.0,0.8,0)
 71node(22,0.2,0.8,0)
 72node(23,0.5,0.8,0)
 73node(24,0.8,0.8,0)
 74node(25,1.0,0.8,0)
 75                 
 76node(26,0.0,1.0,0)
 77node(27,0.2,1.0,0)
 78node(28,0.5,1.0,0)
 79node(29,0.8,1.0,0)
 80node(30,1.0,1.0,0)
 81
 82node(31,0.0,1.2,0)
 83node(32,0.2,1.2,0)
 84node(33,0.5,1.2,0)
 85node(34,0.8,1.2,0)
 86node(35,1.0,1.2,0)
 87                 
 88node(36,0.0,1.4,0)
 89node(37,0.2,1.4,0)
 90node(38,0.5,1.4,0)
 91node(39,0.8,1.4,0)
 92node(40,1.0,1.4,0)
 93
 94node(41,0.0,1.6,0)
 95node(42,0.2,1.6,0)
 96node(43,0.5,1.6,0)
 97node(44,0.8,1.6,0)
 98node(45,1.0,1.6,0)
 99                 
100node(46,0.0,1.8,0)
101node(47,0.2,1.8,0)
102node(48,0.5,1.8,0)
103node(49,0.8,1.8,0)
104node(50,1.0,1.8,0)
105                
106node(51,0.0,2.0,0)
107node(52,0.2,2.0,0)
108node(53,0.5,2.0,0)
109node(54,0.8,2.0,0)
110node(55,1.0,2.0,0)
111
112##########################
113# ELEMENTS 
114##########################
115
116ShellType = "ShellNLDKGQ"
117# ShellType = "ShellMITC4"
118
119element(ShellType,1,1,2,7,6,1)
120element(ShellType,2,2,3,8,7,2)
121element(ShellType,3,3,4,9,8,2)
122element(ShellType,4,4,5,10,9,1)
123
124element(ShellType,5,6,7,12,11,1)
125element(ShellType,6,7,8,13,12,2)
126element(ShellType,7,8,9,14,13,2)
127element(ShellType,8,9,10,15,14,1)
128
129element(ShellType,9,11,12,17,16,1)
130element(ShellType,10,12,13,18,17,2)
131element(ShellType,11,13,14,19,18,2)
132element(ShellType,12,14,15,20,19,1)
133
134element(ShellType,13,16,17,22,21,1)
135element(ShellType,14,17,18,23,22,2)
136element(ShellType,15,18,19,24,23,2)
137element(ShellType,16,19,20,25,24,1)
138
139element(ShellType,17,21,22,27,26,1)
140element(ShellType,18,22,23,28,27,2)
141element(ShellType,19,23,24,29,28,2)
142element(ShellType,20,24,25,30,29,1)
143
144element(ShellType,21,26,27,32,31,1)
145element(ShellType,22,27,28,33,32,2)
146element(ShellType,23,28,29,34,33,2)
147element(ShellType,24,29,30,35,34,1)
148
149element(ShellType,25,31,32,37,36,1)
150element(ShellType,26,32,33,38,37,2)
151element(ShellType,27,33,34,39,38,2)
152element(ShellType,28,34,35,40,39,1)
153
154element(ShellType,29,36,37,42,41,1)
155element(ShellType,30,37,38,43,42,2)
156element(ShellType,31,38,39,44,43,2)
157element(ShellType,32,39,40,45,44,1)
158
159element(ShellType,33,41,42,47,46,1)
160element(ShellType,34,42,43,48,47,2)
161element(ShellType,35,43,44,49,48,2)
162element(ShellType,36,44,45,50,49,1)
163
164element(ShellType,37,46,47,52,51,1)
165element(ShellType,38,47,48,53,52,2)
166element(ShellType,39,48,49,54,53,2)
167element(ShellType,40,49,50,55,54,1)
168
169# P-delta columns
170
171element('truss',41,1,6,223.53e-6,7)
172element('truss',42,6,11,223.53e-6,7)
173element('truss',43,11,16,223.53e-6,7)
174element('truss',44,16,21,223.53e-6,7)
175element('truss',45,21,26,223.53e-6,7)
176element('truss',46,26,31,223.53e-6,7)
177element('truss',47,31,36,223.53e-6,7)
178element('truss',48,36,41,223.53e-6,7)
179element('truss',49,41,46,223.53e-6,7)
180element('truss',50,46,51,223.53e-6,7)
181
182element('truss',51,2,7,223.53e-6,7)
183element('truss',52,7,12,223.53e-6,7)
184element('truss',53,12,17,223.53e-6,7)
185element('truss',54,17,22,223.53e-6,7)
186element('truss',55,22,27,223.53e-6,7)
187element('truss',56,27,32,223.53e-6,7)
188element('truss',57,32,37,223.53e-6,7)
189element('truss',58,37,42,223.53e-6,7)
190element('truss',59,42,47,223.53e-6,7)
191element('truss',60,47,52,223.53e-6,7)
192
193element('truss',61,4,9,223.53e-6,7)
194element('truss',62,9,14,223.53e-6,7)
195element('truss',63,14,19,223.53e-6,7)
196element('truss',64,19,24,223.53e-6,7)
197element('truss',65,24,29,223.53e-6,7)
198element('truss',66,29,34,223.53e-6,7)
199element('truss',67,34,39,223.53e-6,7)
200element('truss',68,39,44,223.53e-6,7)
201element('truss',69,44,49,223.53e-6,7)
202element('truss',70,49,54,223.53e-6,7)
203
204element('truss',71,5,10,223.53e-6,7)
205element('truss',72,10,15,223.53e-6,7)
206element('truss',73,15,20,223.53e-6,7)
207element('truss',74,20,25,223.53e-6,7)
208element('truss',75,25,30,223.53e-6,7)
209element('truss',76,30,35,223.53e-6,7)
210element('truss',77,35,40,223.53e-6,7)
211element('truss',78,40,45,223.53e-6,7)
212element('truss',79,45,50,223.53e-6,7)
213element('truss',80,50,55,223.53e-6,7)
214
215# Fix all bottom nodes
216fixY(0.0,1,1,1,1,1,1)
217
218recorder('Node','-file','ReactionPY.txt','-time','-node',1,2,3,4,5,'-dof',1,'reaction')
219
220############################
221# Gravity Analysis
222############################
223
224print("running gravity")
225
226timeSeries("Linear", 1)					# create TimeSeries for gravity analysis
227pattern('Plain',1,1)
228load(53,0,-246000.0,0.0,0.0,0.0,0.0)	# apply vertical load
229
230recorder('Node','-file','Disp.txt','-time','-node',53,'-dof',1,'disp')
231
232constraints('Plain')
233numberer('RCM')
234system('BandGeneral')
235test('NormDispIncr',1.0e-4,200)
236algorithm('BFGS','-count',100)
237integrator('LoadControl',0.1)
238analysis('Static')
239analyze(10)
240
241print("gravity analysis complete...")
242
243loadConst('-time',0.0)					# Keep the gravity loads for further analysis
244
245wipeAnalysis()
246
247###############################
248### Cyclic ANALYSIS
249###############################
250
251if(AnalysisType=="Cyclic"):
252	
253	# This is a load controlled analysis. The input load file "RCshearwall_Load_input.txt" should be in the 
254	# .. same folder as the model file.
255	
256	print("<<<< Running Cyclic Analysis >>>>")
257	
258	timeSeries('Path',2,'-dt',0.1,'-filePath','RCshearwall_Load_input.txt')
259	pattern('Plain',2,2)
260	sp(53,1,1)								# construct a single-point constraint object added to the LoadPattern.
261
262	constraints('Penalty',1e20,1e20)
263	numberer('RCM')
264	system('BandGeneral')
265	test('NormDispIncr',1e-05, 100, 1)
266	algorithm('KrylovNewton')
267	integrator('LoadControl',0.1)
268	analysis('Static')
269	analyze(700)
270
271
272#######################
273# PUSHOVER ANALYSIS
274#######################
275
276if(AnalysisType=="Pushover"):
277	
278	print("<<<< Running Pushover Analysis >>>>")
279
280	# create a plain load pattern for pushover analysis
281	pattern("Plain", 2, 1)
282	
283	ControlNode=53
284	ControlDOF=1
285	MaxDisp= 0.020
286	DispIncr=0.00001
287	NstepsPush=int(MaxDisp/DispIncr)
288	
289	load(ControlNode, 1.00, 0.0, 0.0, 0.0, 0.0, 0.0)	# Apply a unit reference load in DOF=1
290	
291	system("BandGeneral")
292	numberer("RCM")
293	constraints('Penalty',1e20,1e20)
294	integrator("DisplacementControl", ControlNode, ControlDOF, DispIncr)
295	algorithm('KrylovNewton')
296	test('NormDispIncr',1e-05, 1000, 2)
297	analysis("Static")
298	
299	# Create a folder to put the output
300	PushDataDir = r'PushoverOut'
301	if not os.path.exists(PushDataDir):
302		os.makedirs(PushDataDir)
303	recorder('Node', '-file', "PushoverOut/React.out", '-closeOnWrite', '-node', 1, 2, 3, 4, 5, '-dof',1, 'reaction')
304	recorder('Node', '-file', "PushoverOut/Disp.out", '-closeOnWrite', '-node', ControlNode, '-dof',1, 'disp')
305
306	# Perform pushover analysis
307	dataPush = np.zeros((NstepsPush+1,5))
308	for j in range(NstepsPush):
309		analyze(1)
310		dataPush[j+1,0] = nodeDisp(ControlNode,1)*1000		# Convert to mm
311		dataPush[j+1,1] = -getLoadFactor(2)*0.001			# Convert to kN
312		
313	# Read test output data to plot
314	Test = np.loadtxt("RCshearwall_TestOutput.txt", delimiter="\t", unpack="False")
315	
316	## Set parameters for the plot
317	plt.rcParams.update({'font.size': 7})
318	plt.figure(figsize=(4,3), dpi=100)
319	plt.rc('font', family='serif')
320	plt.plot(Test[0,:], Test[1,:], color="black", linewidth=0.8, linestyle="--", label='Test')
321	plt.plot(dataPush[:,0], -dataPush[:,1], color="red", linewidth=1.2, linestyle="-", label='Pushover')
322	plt.axhline(0, color='black', linewidth=0.4)
323	plt.axvline(0, color='black', linewidth=0.4)
324	plt.xlim(-25, 25)
325	plt.xticks(np.linspace(-20,20,11,endpoint=True)) 
326	plt.grid(linestyle='dotted') 
327	plt.xlabel('Displacement (mm)')
328	plt.ylabel('Base Shear (kN)')
329	plt.legend()
330	plt.savefig("PushoverOut/RCshearwall_PushoverCurve.png",dpi=1200)
331	plt.show()
332	
333	
334	print("Pushover analysis complete")
../_images/RCshearwall_PushoverCurve.png