3d - Connection Design

3D - CONNECTION DESIGN

The stability of a structure soley depends on connections. About 90% of structures fail due to shear resulting mainly at joints. Simple design procedure has been furnished. Design Procedure a) Member end forces (as in Staad output): Beam

L/C

Node

Fx

Fy

Fz

Mx

My

Mz

b) Connection forces: Fxt = Fx + Q + Mz / D + My / B + Mx /√(D2 + B2 + D * B * Sin 4/4 * Cos 4/4) Fyt = Fy + Fz c) Bolts design: Capacity of the bolts in tension

=

Fxt / (Ft * Nr) ≤ 1.0

Capacity of the bolts in shear

=

Fyt / (Fs * Nt) ≤ 1.0

d) Combined capacity: Fxt / (Ft * Nr) + (Fyt + Fz) / (Fs * Nt) ≤ 1.0 e) Thickness of the connection plate ≥ bolt diameter. Notations D – Depth of the section, B – Breadth of the section, Fx – Linear shear (Axial force) in xaxis, Fy – Longitudinal shear in y-axis, Fz – Lateral shear in z-axis, Q – Prying force, Fxt – Total axial force, Fyt – Total shear force, Mx – Torsion along y-axis, My – Bending moment along z-axis, Mz – Bending moment along x-axis, Ft – Bolt capacity in tension, Fs – Bolt capacity in shear, Nr – Number of bolt rows, Nt – Total number of bolts. About the author Mahaveer Janapala is a Structural Engineer and Interface Manager in an EPC Company. Licensed to http://www.ghmc.gov.in. He is a postgraduate in Structural Engineering and a graduate in Civil Engineering from Osmania University (www.osmania.ac.in). He has a post

graduation

in

Biblical

Counseling

from

‘CARE’

Counseling

Institute

(http://carecounseling.mahalife.com/) affiliated to ‘TOPIC’ (www.topic.us). He was born (1977), brought up, educated, working and residing in Hyderabad, India.

1

06-July-09