> with(linalg):
> A[0]:=matrix(1,4,[-6/l^2,-4/l,6/l^2,-2/l]);
> 

                      [   6                6           ]
              A[0] := [- ----    - 4/l    ----    - 2/l]
                      [    2                2          ]
                      [   l                l           ]

> A[1]:=matrix(1,4,[-2/l^2,-2/l,2/l^2,0]);
> 

                        [   2                2       ]
                A[1] := [- ----    - 2/l    ----    0]
                        [    2                2      ]
                        [   l                l       ]

> A[2]:=matrix(1,4,[2/l^2,0,-2/l^2,2/l]);
> 

                         [ 2              2         ]
                 A[2] := [----    0    - ----    2/l]
                         [  2              2        ]
                         [ l              l         ]

> A[3]:=matrix(1,4,[6/l^2,2/l,-6/l^2,4/l]);
> 

                        [ 6                6         ]
                A[3] := [----    2/l    - ----    4/l]
                        [  2                2        ]
                        [ l                l         ]

> M[0]:=multiply(transpose(A[0]),A[0]):
> M[1]:=multiply(transpose(A[1]),A[1]):
> M[2]:=multiply(transpose(A[2]),A[2]):
> M[3]:=multiply(transpose(A[3]),A[3]):
> K:=(EI*l/8)*(M[0]+3*M[1]+3*M[2]+M[3]);
> 

            K := 1/8 EI l (M[0] + 3 M[1] + 3 M[2] + M[3])

> K:=(2*EI/l^3)*evalm((l^4/16)*(M[0]+3*M[1]+3*M[2]+M[3]));
> 

                         [ 6     3 l      -6     3 l ]
                         [                           ]
                         [          2              2 ]
                         [3 l    2 l     -3 l     l  ]
                    2 EI [                           ]
                         [-6     -3 l     6      -3 l]
                         [                           ]
                         [         2                2]
                         [3 l     l      -3 l    2 l ]
               K := ----------------------------------
                                     3
                                    l

# Dieses Ergebnis stimmt mit der Steifigkeitsmatrix in (6.69b) und
# (3.95) in Band 1 berein.
> 
> 
