Welded machine elements Design of basic joints

Analysis of the failure of prematurely damaged welded structures in service very often reveals that the main cause is an inappropriate design of the welded assembly, revealing that the most elementary rules have sometimes been ignored, and sometimes sacrificed to the economic imperative.

It is therefore essential for the designer of mechanically-welded assemblies to be aware of the most common geometric and dimensional configurations. This will enable them to refer to the accepted rules on the constructive provisions to be implemented in order to guarantee the service life of the structure subjected to static or repeated stresses during operation.

These provisions are based on general design principles, in particular layout rules and associated symbolization, as well as the conditions for admissibility of discontinuity at the root, general rules for edge preparation and recommendations specific to different types of elementary joints, such as butt joints or angular joints of flat elements.

The design of welded component assemblies, such as box girders, angular connections of welded frame sections or rotating parts, is covered in the article. [BM 5 192] .

The stakes are high, given that welding is the most common assembly method used in mechanical engineering.

Although this article is intended to be a logical extension of articles [BM 5 186] and [BM 5 187] The practitioner will consult it chronologically once he has decided on the grade of material, and it has been arranged here with this in mind.

At the end of the article, readers will find a glossary and a table of acronyms, notations and symbols.