Page 61 - Using ANSYS for Finite Element Analysis A Tutorial for Engineers
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48  •   Using ansys for finite element analysis
                By using MATLAB, we can solve them and the results are as follows:

                                                  .
                                            ,
                                      .
                R =− .      kNR =   13 675 kN R = 15 680 kN
                              ,
                      7 6722
                  x 1            1 y          1
                R =−  13 483 kNR =−,  42 210.  kN , R = 44 311kN
                        .
                                      2
                                                    .
                  3 x            3 y            3
                R =−  4 4911kNR  4y =− 6 1025kN R = 7 5770kN
                                                         N
                                                    .
                              ,
                                       .
                                              ,
                       .
                  4x
                                                4
                d 2 x = 0 0632 mmd 2 y  = 0 0513 mm
                      .
                             ,
                                    .
                d  =  0 0109 mmd  =  0 0081 mm
                      .
                             ,
                                    .
                 5 x            5 y
                The displacement at point (250, 125) = (0.0109, 0.0081) mm
                We can determine the stresses in each element by using equation:
                 s {}=[][]{}
                      DB d
                The stress for element A, we then have
                                                                  d 1 
                                                                     x
                                                                 d 1y  
                           1  u   0       b   0  b  0   b   0    
                                                                      
                                                                  
                       E               1   1     5       4      d 5x 
                                                                      
                 s {}=      u 1   0   ×    0  g 1  0  g 5  0  g 4 4   
                                                                 
                         2
                       − ( 1  u )     2 A                        d 5y 
                                  1 − u     g   b  g  b  g   b 
                                                                4 
                           00              1  1   5   5   4      d  
                                  2                               4x 
                                                                   d 4y 
                                                                      
                                                                  
                Substituting numerical values for matrix [D], [B] given by the analysis of
                element A and the appropriate part of {d}, we can obtain:
                                                                     0  
                                                                     0  
                             1  0 3  0    −125  0  250  2  −1125  0    0 0109 
                                 .
                                                                  
                                       ×
                 s {}=  210000   03  1  0     0  − 250  0  0  0  250   .  
                              .
                     .
                    091 (62500 )                                 0 0081 1 
                                                                     .
                              0  0  035   − 250 − 125  0  250  250  − 125     
                                        
                                     .
                                                                     0  
                                                                     0  
                 s     10 0615
                       .
                   x      
                 s y   =  3 0185  Mpa
                       .
                 t    2..6169  
                  xy   
                1.9  fea: modeling, errors, and aCCUraCy
                Modeling is the simulation of a physical structure or physical process by
                means of a substitute analytical or numerical construct. It is not simply
                preparing a mesh of nodes and elements. Modeling requires that the phys-
                ical action of the problem be understood well enough to choose suitable
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