Using Belleville Springs to Prevent Bolt Fatigue Failures
Bolted joints are critical to the safe operation of equipment for a wide range of industries and applications, from packaging to electrical connections, valves and flanges, petrochemical and refining operations, to deep sea and offshore drilling equipment, structural systems, crossbows and even ski lifts. Over time, bolts stretch and lose their load due to a variety of reasons. In applications where bolts are subjected to cyclic loading, it can be at risk of fatigue failure. Factors that can impact fatigue failures stem from issues such as insufficient preload, vibration, differential thermal expansion and embedment relaxation. These types of of failures culminates in catastrophic rupture and is preceded by a natural sequence of crack initiation, growth, and propagation.
Download the White Paper, Using Belleville Springs to Prevent Bolt Fatigue Failures
Fatigue failure can be prevented. There are many bolts that are subjected to alternating loads that will not fail due to fatigue. Additionally, the cycle life of any fastener can be predicted. In this paper, we will dicuss several tools that can be used to evaluate a bolt's fatigue limits relative to its application, including the installation of Belleville spring washers to the fastening system. Adding Belleville springs decreases the stiffness of the bolting system relative to that of the joint. Joint diagrams are useful in describing how changes to a bolt, such as stiffness, will influence the cyclical load on the fastener. Download the paper, Using Belleville Springs to Prevent Bolt Fatigue Failures, for a closer look at the science behind the elements of preventing bolting malfunctions and how installing Solon Belleville Springs & Washers increases the elasticity of the bolting system and maintains bolt preload.
Expert Engineering Solutions
If you'd like assistance determining if your existing bolts are suseptible to fatigue failures, or for assistance in selecting the correct Belleville spring washer arrangement, please contact our engineering team.
This article is part of a series on the use of Belleville springs in bolting applications:
- Using Belleville Springs to Maintain Bolt Preload
- Why Bolts Work (and why some don't)
- Why Increased Elasticity Leads to Reduced Self-Loosening
Calculator: Infinte Bolt Fatigue Life Calculator
Application: General Purpose Bolting
Application: Commercial Bolting Applications
Technical White Paper: Using Belleville Springs to Maintain Bolt Preload
Video: Solon Belleville Spring Washers
Other Product Selection Tools: Application Specific Calculators
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