Strength of Elements Under Tensile Effect
If axial tensile elements are used together with bolted joints, yield stress will be reached earlier in the areas where bolt holes are located. This situation will affect the strength calculations made by using the load-displacement curve and assuming linear elastic.
In bolted and welded joints of tensile members, the cross-sectional area operating in load transfer is not equal to the entire cross-section area, as a result of the uneven distribution of the load.
Since the L and U sections used especially in the crosses are not connected with bolts or welding, a certain region called effective area in load transfer works. Due to this phenomenon called 'Shear Lag' effect, effective net area is used in the design of pulling elements.
3 different areas are used in the strength calculation in tensile members:
Lossless Area (Ag)
Net Area (Moment)
Effective Net Area (Ae)
Design with ÇYTHYE 2018
There are 3 different collapse conditions in the elements affected by the tensile force: Flow Limit State, Breaking Limit State and Block Breaking Limit State
The design tensile strength is taken as the minimum strength to be calculated according to the yield limit state, fracture limit state and block break limit state of the element under axial tensile force. Block breaking limit situation used in end joints of tensile members is given in ÇYTHYE 2018 Section 13.4.3. Block break limit state is an additional check for joins.
Pull element slenderness should be controlled. In accordance with article 7.1.1 of the regulation , the slender ratio should be less than 300.
Flow Limit State
The characteristic tensile strength for the yield limit state in tensile members is calculated by equation 7.2 using the cross-section area without loss T n .
Refraction Limit State
The characteristic tensile strength, T n , for the fracture limit state in tensile members is calculated by equation 7.3 using the effective net cross-sectional area.
Block Break Boundary Status
The characteristic block breaking strength is calculated by equation 13.19, based on the yield and fracture limit states along the Rn shear surface or surfaces and the rupture limit states along the vertical tensile surface.
Icons
A g : Cross-section area without loss
A e : Effective net cross-sectional area
A n : Net cross-section area
A gv : Area without loss under shear stress
A nv : Net area under shear stress
A nt : Net area under tensile stress
F y : Structural steel characteristic yield stress
F u : Structural steel characteristic tensile strength
K : Twisting length coefficient
L: Element length between supported points
i: Radius of inertia
U: Stress irregularity effect coefficient
U bs : A coefficient considering the spread of tensile stresses
T n : Design tensile strength