Shear Connection Design
Shear Connection design is made automatically according to the Design, Calculation and Construction Principles of Steel Structures (ÇYTHYEDY) (GKT and YDKT) and AISC 360-16 (ASD and LRFD) regulations. Bolt, weld and plate controls, geometry controls and strength controls are done automatically in accordance with the steel connection type.
Types of shear connections are listed below.
The failure mechanisms and strength assumptions used in the design of shear connections and connection elements are found as follows according to ÇYTHYEDY 2018 and AISC 360-16 regulations.
Design Criteria for Shear Connection
It is assumed that the entire shear force is resisted by the web of the cross-section.
There is no interaction between shear force and bending moment.
Shear strength is determined using the formula:
Shear Strength
In stiffened and unstiffened single and double symmetrical cross-sections, the characteristic shear strength in the web is calculated as follows:
The coefficients for the I-cross section elements according to the slenderness ratio are determined as follow:
The allowable shear strength is calculated as follow:
Bearing Connections
In the bearing connections, the strength is determined according to the smallest one by controlling 3 limit conditions.
Shear failure at bolt.
Bearing limit state in the plate.
i) Tear-out limit state of the plate.
ii) Bearing limit state of the plate.
Characteristic Tensile and Shear Stress Strengths of Bolts
Characteristic tensile strength Fnt of bolts is calculated depending on the characteristic tensile strength of bolt material Fub given in Table 2.2.
The characteristic shear stress strength of bolts, Fnv, is calculated in two different ways:
i) If the threaded part of the bolt is in the shear plane.
ii) If the threaded part of the bolt is outside of the shear plane.
Characteristic Tensile Force Strength of Bolt Under the Combined Effect of Tensile and Shear Force
The characteristic tensile force or shear strength of prestressed high strength bolts, simple tightened bolts and threaded cross sections are calculated according to the rupture limit state for the tensile forces or and tear-out limit state for shear forces.
Bearing Connections under the Combined Effect
Bearing Limit States in the Plate (Bolt Holes)
The compressive stresses that occur between bolt and plate are because of excessive deformations on the bolt and plate.
In order to compute the bearing stress between the bolt and the hole edge, the assumption of uniform distribution of stresses on this surface is defined.
Bearing Failure of the Bolt Hole
Tear-out Failure of the Plate
The characteristic bearing force resistance Rn of a bolt hole is calculated based on the bearing limit state under the shear effect as follow:
Regardless of the direction of the load, for connections formed from standard, oversized and short-slotted holes or long-slotted holes with oval longitudinal axis parallel to the direction of the load:
For connections formed with slotted holes with oval longitudinal axis perpendicular to the direction of the load:
Safety factors depend on the method being used:
Shear Resistance
The characteristic shear strength Rn of the cross-section and connection elements under shear effect for the yield and rupture limit states calculated as follow:
Yielding Limit State
Rupture Limit State
Block Shear Limit State
The characteristic block shear strength Rn is calculated on the basis of the yield and rupture limit states along the shear surface or surfaces and the rupture limit states along the tensile surface.
Tensile Strength
The characteristic tensile strength Rn of the cross-section and connection elements under the shear effect for tensile action is calculated for the yield and rupture limit states as follows:
Yielding Limit State
Rupture Limit State
Symbols
Ab: Non-threaded bolt characteristic cross-sectional area
Aw: Cross-section web area
Ag: Gross area
Ae: Effective net area
An: Net area
Agv: Gross shear area
Anv: Net shear area
Ant: Net tensile area
Cv: Coefficient of reduction for shear buckling
d: Characteristic of bolt diameter
dh: Bolt hole diameter
Fy: Specified yield stress of the type of steel being used, ksi (MPa)
Fu: Specified ultimate stress of the type of steel being used, ksi (MPa)
Fnt: Characteristic tensile tensile strength given in Table 13.7
F'nt: Reduced characteristic tensile stress obtained by considering shear force effect
Fnv: Characteristic shear stress strength given in Table 13.7
frv: The greatest shear stress in the characteristic thread area of the bolt under YDKT or GKT load combinations
Fyb: Bolt characteristic yield strength
Fub: Bolt characteristic tensile strength
nsp: Number of shear planes
Ubs: A coefficient considering the distribution of tensile stresses
s: Distance between bolt holes center
Le: The distance from the center of the bolt hole to the edge of the connected element
t: Plate thickness
Rnt : Characteristic tensile strength
Rnv : Characteristic shear strength
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