Example 5.9 (Corner nodes: linear elements)
 
Input 
 
Number of Boundary Elements = 20 
 
Number of InteriorPoints = 3 
 
Coordinates of the Extreme Points  of the  Boundary Elements  
 
Point      X          Y
 1      10.0200     0.0000
 2      15.0000     0.0000
 3      20.0000     0.0000
 4      25.0000     0.0000
 5      29.9800     0.0000
 6      29.9930     0.6280
 7      27.7160    11.4800
 8      21.2130    21.2130
 9      11.4800    27.7160
10       0.6280    29.9930
11       0.0000    29.9800
12       0.0000    25.0000
13       0.0000    20.0000
14       0.0000    15.0000
15       0.0000    10.0200
16       0.2090     9.9970
17       3.8260     9.2380
18       7.0710     7.0710
19       9.2380     3.8260
20       9.9970     0.2090
 
Boundary  Conditions 

               First Node             Second Node
               Prescribed             Prescribed
Element     CODE   Value           CODE    Value
 1			 1     0.0000			 1     0.0000
 2			 1     0.0000			 1     0.0000
 3			 1     0.0000			 1     0.0000
 4			 1     0.0000			 1     0.0000
 5			 1     0.0000			 0   400.0000
 6			 0   400.0000			 0   400.0000
 7			 0   400.0000			 0   400.0000
 8			 0   400.0000			 0   400.0000
 9			 0   400.0000			 0   400.0000
10			 0   400.0000			 1     0.0000
11			 1     0.0000			 1     0.0000
12			 1     0.0000			 1     0.0000
13			 1     0.0000			 1     0.0000
14			 1     0.0000			 1     0.0000
15			 1     0.0000			 0  1000.0000
16			 0  1000.0000			 0  1000.0000
17			 0  1000.0000			 0  1000.0000
18			 0  1000.0000			 0  1000.0000
19			 0  1000.0000			 0  1000.0000
20			 0  1000.0000			 1     0.0000

Interior Point Coordinates

       Xi         Yi
    18.4770     7.6530
    14.1420    14.1420
     7.6530    18.4770
 


Solution: 

Boundary Nodes 
          (X,Y)               u       Prenodal q  Postnodal q
(   10.0200,     0.0000)   994.2385     0.0000     0.0000
(   15.0000,     0.0000)   775.7902     0.0000     0.0000
(   20.0000,     0.0000)   617.7277     0.0000     0.0000
(   25.0000,     0.0000)   495.1684     0.0000     0.0000
(   29.9800,     0.0000)   404.1536     0.0000     0.0000
(   29.9930,     0.6280)   400.0000   -20.6881   -20.6881
(   27.7160,    11.4800)   400.0000   -17.7511   -17.7511
(   21.2130,    21.2130)   400.0000   -18.4223   -18.4223
(   11.4800,    27.7160)   400.0000   -17.7511   -17.7511
(    0.6280,    29.9930)   400.0000   -20.6881   -20.6881
(    0.0000,    29.9800)   404.1536     0.0000     0.0000
(    0.0000,    25.0000)   495.1683     0.0000     0.0000
(    0.0000,    20.0000)   617.7277     0.0000     0.0000
(    0.0000,    15.0000)   775.7900     0.0000     0.0000
(    0.0000,    10.0200)   994.2382     0.0000     0.0000
(    0.2090,     9.9970)  1000.0000    61.6049    61.6049
(    3.8260,     9.2380)  1000.0000    53.1925    53.1925
(    7.0710,     7.0710)  1000.0000    55.4601    55.4601
(    9.2380,     3.8260)  1000.0000    53.1924    53.1924
(    9.9970,     0.2090)  1000.0000    61.6050    61.6050


Interior Points 
          (Xi,Yi)            u          q_x          q_y
(   18.4770,     7.6530)   618.6967   -25.3328    -10.5420
(   14.1420,    14.1420)   618.4972   -19.3454    -19.3454
(    7.6530,    18.4770)   618.6967   -10.5420    -25.3328