/[escript]/trunk/finley/test/python/seismic_wave.py
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Annotation of /trunk/finley/test/python/seismic_wave.py

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Revision 843 - (hide annotations)
Thu Sep 7 05:55:12 2006 UTC (13 years, 6 months ago) by gross
File MIME type: text/x-python
File size: 5221 byte(s)
some timing added
1 gross 842 """
2     seismic wave propagation
3    
4     @var __author__: name of author
5     @var __licence__: licence agreement
6     @var __url__: url entry point on documentation
7     @var __version__: version
8     @var __date__: date of the version
9     """
10    
11     __copyright__=""" Copyright (c) 2006 by ACcESS MNRF
12     http://www.access.edu.au
13     Primary Business: Queensland, Australia"""
14     __license__="""Licensed under the Open Software License version 3.0
15     http://www.opensource.org/licenses/osl-3.0.php"""
16     __author__="Lutz Gross, l.gross@uq.edu.au"
17     __url__="http://www.iservo.edu.au/esys/escript"
18     __version__="$Revision$"
19     __date__="$Date$"
20    
21     from esys.escript import *
22     from esys.escript.linearPDEs import LinearPDE
23     from esys.finley import Brick
24 gross 843 import time
25 gross 842
26 gross 843 output=False
27     n_end=100
28    
29 gross 842 resolution=4000. # number of elements per m
30     l=80000. # width and length m
31     h=30000. # height in m
32    
33     rho_bedrock=8e3
34     mu_bedrock=1.7e11
35     lambda_bedrock=1.7e11
36    
37     l_x_water=10000 # length of water in x
38     l_y_water=10000 # length of water in y
39     h_water=max(2000,resolution) # depth of water region
40    
41     water_tag=2
42     rho_water=1e3
43     mu_water=0.
44     lambda_water=1.e9
45    
46     d0_sand=10000 # thickness of sand region on surface
47     d_sand=max(2000,resolution) # thickness of sand layer under the water
48    
49     sand_tag=3
50     rho_sand=5e3
51     mu_sand=1.5e10
52     lambda_sand=1.5e10
53    
54    
55     # location and geometrical size of event:
56     xc=[30000.,40000.,10000.]
57     src_radius = 0.1*h
58     # direction of event:
59     event=numarray.array([1.,0.,0.])*1.e6
60     # time and length of the event
61     tc_length=2.
62     tc=sqrt(5.*tc_length)
63 gross 843 if output:
64     print "event location = ",xc
65     print "radius of event = ",src_radius
66     print "time of event = ",tc
67     print "length of event = ",tc_length
68     print "direction = ",event
69 gross 842
70 gross 843 t_end=20.
71 gross 842
72     def getDomain():
73     """
74     this defines a dom as a brick of length and width l and hight h
75    
76    
77     """
78 gross 843 global netotal
79 gross 842 ne_l=int(l/resolution+0.5)
80     ne_h=int(h/resolution+0.5)
81 gross 843 netotal=ne_l*ne_l*ne_h
82     if output: print "grid : %s x %s x %s"%(ne_l,ne_l,ne_h)
83 gross 842 dom=Brick(ne_l,ne_l,ne_h,l0=l,l1=l,l2=h,order=1)
84    
85     fs=Function(dom)
86     x=Function(dom).getX()
87     fs.setTags(sand_tag,wherePositive(x[0]-(l-l_x_water-d0_sand)) \
88     *wherePositive(x[1]-(l-l_y_water-d0_sand)) \
89     *wherePositive(x[2]-(h-h_water-d_sand)))
90     fs.setTags(water_tag,wherePositive(x[0]-(l-l_x_water)) \
91     *wherePositive(x[1]-(l-l_y_water)) \
92     *wherePositive(x[2]-(h-h_water)))
93     return dom
94    
95     def getMaterialProperties(dom):
96     rho =Scalar(rho_bedrock,Function(dom))
97     rho.setTaggedValue(sand_tag,rho_sand)
98     rho.setTaggedValue(water_tag,rho_water)
99    
100     lame_mu =Scalar(mu_bedrock,Function(dom))
101     lame_mu.setTaggedValue(sand_tag,mu_sand)
102     lame_mu.setTaggedValue(water_tag,mu_water)
103    
104     lame_lambda=Scalar(lambda_bedrock,Function(dom))
105     lame_lambda.setTaggedValue(sand_tag,lambda_sand)
106     lame_lambda.setTaggedValue(water_tag,lambda_water)
107    
108     return rho,lame_mu,lame_lambda
109    
110    
111     def wavePropagation(dom,rho,lame_mu,lame_lambda):
112     x=Function(dom).getX()
113     # ... open new PDE ...
114     mypde=LinearPDE(dom)
115     mypde.setSolverMethod(LinearPDE.LUMPING)
116     k=kronecker(Function(dom))
117     mypde.setValue(D=k*rho)
118    
119     v_p=sqrt((2*lame_mu+lame_lambda)/rho)
120 gross 843 if output: print "v_p=",v_p
121 gross 842 v_s=sqrt(lame_mu/rho)
122 gross 843 if output: print "v_s=",v_s
123 gross 842 dt=(1./5.)*inf(dom.getSize()/v_p)
124 gross 843 if output: print "time step size = ",dt
125 gross 842 # ... set initial values ....
126     n=0
127     t=0
128     # initial value of displacement at point source is constant (U0=0.01)
129     # for first two time steps
130     u =Vector(0.,Solution(dom))
131     u_last=Vector(0.,Solution(dom))
132    
133 gross 843 starttime = time.clock()
134     while t<t_end and n<n_end:
135     if output: print n+1,"-th time step t ",t+dt," max u and F: ",Lsup(u),
136 gross 842 # ... get current stress ....
137     eps=symmetric(grad(u))
138     stress=lame_lambda*trace(eps)*k+2*lame_mu*eps
139     # ... force due to event:
140     F=exp(-((t-tc)/tc_length)**2)*exp(-(length(x-xc)/src_radius)**2)*event
141 gross 843 if output: print Lsup(F)
142 gross 842 # ... get new acceleration ....
143     mypde.setValue(X=-stress,Y=F)
144     a=mypde.getSolution()
145     # ... get new displacement ...
146     u_new=2*u-u_last+dt**2*a
147     # ... shift displacements ....
148     u_last,u=u,u_new
149     # ... save current acceleration in units of gravity and displacements
150 gross 843 if output:
151     if n%10==0: saveVTK("disp.%i.vtu"%(n/10),displacement=u, amplitude=length(u))
152 gross 842
153     t+=dt
154     n+=1
155    
156 gross 843 endtime = time.clock()
157     totaltime = endtime-starttime
158     global netotal
159     print ">>number of elements: %s, total time: %s, per time step: %s <<"%(netotal,totaltime,totaltime/n)
160 gross 842 if __name__ =="__main__":
161     dom=getDomain()
162     rho,lame_mu,lame_lambda=getMaterialProperties(dom)
163     wavePropagation(dom,rho,lame_mu,lame_lambda)

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