Assurance of Reliability in Fabricated Steel Structures Through Nondestructive Testing

Reliability in steel fabricating and erection through nondestructive testing is becoming a very important part of shipbuilding, bridge construction, and building construction. Requirements for nondestructive tests, so far as the method to be used and the techniques and criteria to be applied, are usually based upon current practices in other industries. Nondestructive testing in the structural industry and, for that matter, all inspection procedures, should be evaluated based upon the end result desired. Often rigid quality assurance requirements are imposed where only good quality control procedures are necessary. The acceptance standards chosen for a particular nondestructive test technique and application are often based upon acceptance requirements derived from nondestructive tests using a different method. Even when acceptance criteria recognize the ability and limitations of a particular technique, they seldom are based upon service experience or anticipated failure conditions. In fact, most of our acceptance criteria can be traced directly back to the ASME Boiler Code. Most of the considerations which go into the designing of a boiler are not valid for fabricated steel structures of other types. Reliability of welded structures at a cost commensurate with the value obtained can only be achieved when nondestructive tests, methods, techniques, and acceptance standards are designed around the specific application to which they will be applied.