Foreword

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This document was prepared by Technical Committee ISO/TC 167, Steel and aluminium structures.

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Introduction

Structural safety is needed in high public occupancy facilities, tall or large-scale structures, and other important facilities. Higher performance is needed for structures subjected to seismic actions. In the case of steel frame structures, integrity of welded joints determines the structural safety of these structures, because welding is often used with beam to column connections, joints of steel members, member assembly, etc. It is especially important to ensure the strength and toughness of the welds.

This document addresses the mechanical testing methods and acceptance criteria for weld metal and heat affected zones. These mechanical properties, coupled with appropriate designs for the seismic force resisting system, proper connection designs and detailing, as well as appropriate weld quality and inspection criteria are essential to ensuring the high structural safety of steel structures of seismic design.

This document specifies the target performance regarding the strength and toughness of welded joints in the acceptance criteria, but does not mention the means for realizing the performance. Rather, the document intends to present the performance-based standards, in recognition of diverse construction methods and the need to promote and disseminate new technologies.

1 Scope

This document defines two performance levels for welded joints, namely Basic Demand and Critical Demand, for longitudinal tensile strength of weld metals, impact toughness of weld metals and heat affected zones (HAZ) to suit the level of seismic performance specifications required for welded steel structures.

This document supplements the provisions of the standards or codes for welding procedure qualification in the application of new steel materials, welding consumables, or complex joints, for welds that require the performance of Basic or Critical Demands as specified by the engineer in the contract.

2 Normative references

3 Terms and definitions

4 Welded joints

4.1 Applicable structural performance

4.2 Mechanical properties of base metal

5 Mechanical testing

5.1 Type of testing

5.2 Test specimens

5.3 Testing procedure

6 Acceptance criteria

6.1 Basic Demand

6.2 Critical Demand

7 Re-testing

8 Test reports

Bibliography