Bab 6- Kilasan aci

Contoh 3

Sebatang aci keluli bulat padu berdiameter 60 mm dipasang tegar ke dalam tiub aluminium yang berdiameter luar 130 mm. Kirakan momen luas kedua bagai kedua-dua bahan tersebut.

A solid circular steel shaft with a diameter of 60 mm mounted in rigid aluminium tube outer diameter 130 mm. Calculate the section moment of area like the tow materials

           

Penyelesaian :

Data Diberi:

D_keluli         = 60mm

D_Aluminium  = 130mm

Momen Luas Kedua Aci Keluli

       J_Keluli  =  J_padu

                                      πD⁴

      J_{aci keluli padu}       =   -------

                                      32

                             

                                     π (60 x 10^-3)⁴

                                =   ----------------

                                            32

     

                                 = 1.272 x 10-6³ m⁴

Momen luas Kudua Aci Aluminium                    

      

                            J_aluminium =  J_geronggong

                                                   π

      J_{aci aluminium geronggong}    =   ---- ( D⁴ – d⁴)

                                                 32

                                                  π

                                            =  ---- ( 0.13⁴ – 0.06⁴)

                                                 32

                                            =  2.677 x 10^-5 m⁴