Page 134 - Marine Structural Design
P. 134

110                                               Part I Structural Design Principles

                           a  P   o   o   00
                           -Pao  o        00
                            0   01 0  00                                             (6.13)
                      [TI =
                            0   ooil  po
                            o   00-PRO
                            0   00 0      01
                 with A = cosa, p = sin a.
                 Similarly, we have for the nodal displacement components:

                      @I= [TW
                      @> = [TIT @I
                 where (i7) and (u) are defined by











                 Based on the element stifiess equation in the local axes,
                      @I= rm@)                                                        (6.14)

                 we may easily obtain, the element stiffness equation in the global axes,
                      [KI = [TIT[m [TI                                                (6.15)




















                             Figure 6.4   Nodal Forces for 3D Beam Element in Local Axes


                 If we write force and corresponding displacement vectors as
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