Issue 51

F. Jafari et alii, Frattura ed Integrità Strutturale, 51 (2020) 136-150; DOI: 10.3221/IGF-ESIS.51.11

  

* V M C V M C   *

  

r

r

s

s





    





ACIG

0

(12)

& V B

* b d w

I

* b d w

I

The safety surface of bending-torsion-shear The following limit sate function ( ACIG states of shear, bending, and torsion.

, & ) V B T

is considered to obtain the safety surface of the ACI standard for three









   

* V M c  

   

 * T b d  1.7 * * r w

* T b d 

* 2

* 2

* M c

V

s

w

r

r

s

s

      













ACIG

0

(13)

, & V B T







2

2

I

* b d w

I

* b d w

w b d

w b d

* * 1.7

In Eqn. 13, three states of shear, bending and torsion effect appear simultaneously and by considering this limit state function, the safety surface is predicted. Sections and dimensions In order to calculate the beta index of T, L, and the rectangular cross-section beams, specified geometrical futures are assumed as shown in Fig. 1 and Tab. 2. The distributed load (25kN/m) is exerted on the beam length. Cross-sections of the mentioned beams are selected in such a way that the area of the T-shape section is twice that of L-shape section and the rectangular section area was  * w b d .

Figure 1 : Schematic figure of the L, T, and Rectangular sections

y f (MPa )

f (MPa) c 

w b (mm)

D q (kN/m)

e b (mm)

450

25

21

850

420



 t t

* ; D M ratio M ratio  L

 

d(mm)

L(mm)

1 /

f b (mm)

200

400

2000

0.4-1.0

Table 2 : The nominal parameters of this study

140