INVESTIGATION OF COLD FORMED STEEL CONNECTIONS

Student:Udit Kumar RoyA2369914014M.Tech Structures

Guide:Mr. Nilesh B. Mishra

CONTENTS

• Introduction• Literature Survey• Objective • Methodology• Plan• Schedule of Project• References

INTRODUCTION• Cold-formed steel (CFS) are products made by rolling or pressing steel into semi-finished or finished goods at low temperatures. The sections are light-weight materials and suitable for low-rise building construction.

• Connection - important elements to achieve its structural stability. Three types of connections - Screw, Welded and Bolted.

• Both bolts and self-drilling screws - common fasteners in cold-formed steel construction. Bolted moment connections with high strength and stiffness are essential in safe, economical design and construction of purlin systems, and thus there are development of purlin-rafter connections in modern roof systems. They are basically beam-to-beam connections with different degrees of continuity to reduce mid-span moment and deflection.

• To extend the effective use of cold-formed steel in building, it is desirable to build safe and economical moment frames, and design information on bolted moment connections in beam-column sub-frames should be provided.

• Screw connection is a convenient method for joining thin steel section or steel sheeting. It does not require heavy and precise tools at site. The difficulty of self-drilling process increases with the increment of steel thickness and steel grade.

• Welded joints provide rigid joints between the cold-formed steel members, but the heat from welding process reduces the strength of the members.

• For ease of construction, the bolted connection is preferable in the construction sector. The reduction of skilled worker at construction site with bolted connection application is able to minimize the construction cost. Bolted connection in cold-formed steel structure is able to achieve semirigid behaviour according to stiffness classification.

LITERATURE SURVEY

• M F Wong and K F Chung (2000): Experimental Investigation of Cold Formed Steel Beam Column sub frames.

• This paper presents the findings of an experimental investigation on the structural performance of bolted moment connections in cold-formed steel beam-column sub-frames. A total of eight tests with three different connection configurations in both internal and external columns were carried out.

• Among the tests, three different modes of failure were identified and the measured moment resistances at the connections varied from 35-95% of the measured moment capacities of the cold-formed steel sections, demonstrating that bolted moment connections between cold-formed steel members are structurally feasible and economical.

• James B.P. Lim (2016): Lim and Nethercot have conducted full-scale cold-formed steel portal frame tests.

• This paper proposes that the difference in the moment carrying capacity of two frames can be attributed to the bimoment, even though back to back channel-sections were used.

• The paper has demonstrated that the Direct Strength Method (DSM)of design of cold formed steel structural members can be used to predict the strength of bolted moment connections in cold-formed steel portal frames where the connection involves either a long or short bolt-group.

OBJECTIVE

• The aim of this project is to investigate the strength of various Cold formed Steel connections using various sections and to study the structural performance.

• To Find best suitable method which can be less time consuming and can give more accurate result.

METHODOLOGY

• Selection of Codes which follow Cold formed Steel design analysis in construction.

• Selection of various sections and determining the strength of connections.

• Calculating various loads on connections as per the proposed and existing codes.

• Adopting the most efficient method for load calculation and study the strength parameters.

Welded Connection

Bolted Connection

PLAN AND ELEVATION

SCHEDULE OF PROJECT COMPLETION

Sr No Jan 2016 Feb 2016 Mar 2016 Apr 2016 May 2016

Status Completed Progress To be Done To Be done To be done

1 Problem Formulation

 Literature collection       

2  Literature collection

Calculation of Dead Load, Live Load      

3   Software learning Modeling in software    

4   Manual Calculations 

Validation of manual calculations

 Result & comparison

 Thesis writing

5       Thesis writing Publication

6       Seminar  Viva

REFERENCES

• IS 801 (1975) : Code of practice for use of Cold Formed steel design and Construction. • M F Wong and K F Chung (2000): Experimental Investigation of Cold Formed Steel Beam Column sub frames.

• James B.P. Lim (2016): DSM for ultimate strength of bolted moment connections between Cold formed steel channel members.

Thankyou