Fasteners

Fasteners play a critical role in engineered structures as a method of nonpermanent joining for the aerospace, infrastructure, civil, automotive, energy generation/distribution, and many other industries.

The objective of this tutorial is to provide substantial introduction into the technology and physics of various, common fasteners.

Content
I. Introduction to Fasteners Lecture #1
I-A. Introduction
I-B. Bolts
I-C. Screws
I-D. Nuts and Washers
I-E. Rivets
I-F. Application Problems and Solutions
I-G. Stainless Steel Fasteners
I-H. Anchor Bolts
I-I. Bolt Plate Fasteners


II. Physics of Fasteners Lecture #2
II-A. Fastener Fatigue
II-B. Strength of threads
II-C. Corrosion of Fasteners
II-D. Fastener Materials and Standards
II-E. Modes of Failure of a Riveted Joint


Fastener failures can lead to disastrous consequences and substantial financial losses. One of the most common fastener failure modes is fatigue crack initiation and growth. Inadequate design considerations, material problems, insufficient preload, loosening, and excessive loads can all contribute to fastener fatigue. Similar to other metallic components, fastener failures include overload, corrosionrelated cracking, embrittlement, creep, and fatigue. Fastener overload can occur upon installation or in service due to an externally applied load. Fastener overload failure investigation should include assessment of the material properties to determine fastener strength, as well as the loads that contributed to the break. Stress corrosion cracking (SCC), or hydrogen embrittlement in some metals, represents an important failure mode in fasteners due to the static tensile nature of the loading in many applications.

The tutorial also discusses the expected stresses on fasteners and the material and environment mitigating SCC or hydrogen embrittlement potential.