Issue 41

Ch. F. Markides et alii, Frattura ed Integrità Strutturale, 41 (2017) 396-411; DOI: 10.3221/IGF-ESIS.41.51 400 In addition, with m =3,5,7,9,…,                                         2 2 2 2 2 2 2 1 2 1 1 2 2 1 2 1 1 2 1 1 1 1 1 1 2 1 2 1 1 2 2 1 2 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m t a t b t a t b A i t t t t t t t t t a t b t a t b B i t t t t t t t t                                                          (12) where     1,2 1,2 1,2 1 1 t i i      (13) and , , , m m m m a b a b     are the real and imaginary parts of the following constants (as coefficients of the Fourier series representation of the boundary conditions on L ): (14) What is more, and again for m =3,5,7,9,…,         2 2 2 2 2 2 1 ,2 1,2 1,2 1,2 1,2 1,2 1,2 1,2 1,2 1 1 1 1 m m m m m m P z z z R z z R R i                                    (15) Finally,                   0 0 0 1 1 1 1 1 1 1 1 , , x y xy b b Ri a a R a a Ri b b R             (16) indicate constant stresses throughout the disc cross-section [20], where the respective coefficients of Fourier series representation of the boundary conditions on L read as [14]: 2 1 2 2 2 1 1 2 sin 2 sin 2 cos 2 2 sin 2 sin 2 2 2 2sin 2sin i o i c o o o o o o o o o o o a P R e e b i                                                (17)     3 2 2 3 2 2 2 2 1 sin 2 cos 2 sin 4 1 sin 2 sin 2 6 2 4 2sin sin 4 2cos 2 sin 4 sin 2 cos4 2 3 2sin 1 sin 1 sin 1 1 2 1 2sin i c o o o o o o o o i o i o o o o o o o m o c m o a P R e b i e e a m m P R b i m m                                                                                                        1 2 2 2 1 1 cos 2 sin 1 2sin 2 cos 1 1 cos 4 1 1 sin 1 sin 1 1 5,7,... 2 1 1 2sin 1 cos 2 sin 1 2sin 2 cos 1 1 cos 4 1 o i m o o o o o o o c o i m o o o o m m m m m e m m m P R m i m m m m m m m e m                                                                                1 o  