PSI - Issue 59

Andrii Pavluk et al. / Procedia Structural Integrity 59 (2024) 566–574 Andrii Pavluk et al./ Structural Integrity Procedia 00 (2019) 000 – 000

570

5

z

z

z

2

2

2 1

1 2 2

( ) N fudA fu fbdz    ( ) ( )

(

( )

) ( 

) a z a dz  1 2 с

E z k с с  

z

1

1

2

с

2

c

z

z

z

1

1

1

3 2

z

z

2 1

1

1

1

1

2

2 3

2 2 a z dz E a  )

с

( E a z

( )

( )

E z a k 

a z k 

1

2 2

1

2

2

1 3

с

с с с

с

с

с

z

1

2

2 2 2

4 2 4

3 2 3

3

z

z

z

z

z

1

1

1

1

1

2

2

1

1

с

с

с

с

с

( )

( )

E a

k

a

k

a

E a

E a

2

2

1

2

2

1

2

с

с

с

2

3

4

3

z

z

1

1

2

2

1

1

с

с

( )

( )

,

k

a

k

a

2

1

2

2

4

3

(11) Substituting formulas (10) and (11) into equation (9), we obtain:

2

3

3

2

4

1

1

1

1

1

z

z

z

z

z

2

2

( N b E 

( )

)

( )

k

E a

E a

k

a

1

1

2

2

2

с

с

с

с

с

2

1

2

2

1

c

с

с

с

2

3

3

4 2

4

z 

3

3

2

3

1

1

1

1

1

z

z

z

z

2

2

2

( )

( )

( )

.

k

a

1 E a E a  с

k

1 a k  с

a

2

1

1

с

с

с

2

2

1

2

2

1

2

2

с

с

3

3

2

4

3

(12) The tensile force in the normal cross-section of the bending element:

1 t t N N N   t

,

2

(13)

z

z

z

2

1 z N fudA fubdz E xbdz E b          1 1 1 2 2 1 1 ( ) ( ) t t t t

,

1

t

2

0

0

0

(14)

z

z

z

z

1

1

2

2

2

2

1 z  z

2

( ) N fudA fu fbdz E z az adz        ( ) ( ) ( )

(

E a z

2

2

2

1

2

1

t

t

t

t

t

t

3 E a E a   1 1 1 t z

z

z

z

1

1

1

3

2

2

1

1

1

z

z

) E a z dz E a 

.

E a

2

2

1

t

t

t

2

1

2

1

2

t

t

t

t

t

t

3

2

3

2

(15) By substituting formulas (14) and (15) into equation (13), we obtain:

3

2

3

2

1

1

1

1

1

z

z

z

z

.

2 N E bz E a E a    t

1 E a E a  t

2

1

t

t

1

1

2

1

2

t

t

t

t

t

t

t

3

2

3

2

(16) The bending moment from the neutral axis for the compressed zone in the normal cross-section is equal to:

2 ,

1 c c M M M   c

(17)

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