WINTER 2023

98 THE DISTRIBUTOR’S

98 THE DISTRIBUTOR’S LINK GUY AVELLON WHAT DISTRIBUTORS NEED TO KNOW ABOUT JOINT STRENGTH from page 12 FIGURE 2 Figure 2 illustrates a bolt and joint with approximately the same stiffness, as they are both absorbing an equal amount of the applied load F. the use of a washer. In simple terms, the bolt does not experience the entire force of the external load. The vast majority of any additional load is absorbed by the clamped joint members because the joint is much softer than the bolt. In fact, it is five (5) times softer than the bolt. This is the reason why bolts tensioned at or near their yield point can often resist significant external loads. A good example are the head bolts on an engine. At some point, the external load can be great enough to cause the clamp load to become completely unloaded. Any further additional load from this point will become entirely added to the tension of the existing bolt. The following is a joint diagram (Figure 4) for a static service load. FIGURE 3 Figure 3 illustrates a softer or more springy fastener in a stiffer joint. The bolt has an increased strain and the joint is absorbing the greater amount of the load F. If the bolt is less stiff, with respect to the joint, the bolt will experience a smaller percentage of the external load, which depends upon the stiffness ratio of the bolt and joint. This helps in determining what type and size of bolt to use in the joint. The stiffness ratio can also help determine preloads, loss due to embedment and bolt failure. Other critical factors to consider are the hole size, surface finish of the contacting joint faces, flatness and FIGURE 4 Further completing the joint diagram under static load conditions, the initial bolt preload Fp is represented by the elastic load curve from O to A. The strain, or bolt deformation is B, represented by O to B. CONTINUED ON PAGE 146

THE DISTRIBUTOR’S LINK 99 NEW ENGLAND FASTENER DISTRIBUTORS ASSOCIATION PO Box 151, Lake Zurich, IL 60047 TEL 847-370-9022 FAX 847-516-6728 EMAIL nefda@nefda.com WEB www.nefda.com LAURA MURPHY NEW ADMINISTRATOR FOR NEFDA As Nancy Rich moves toward retirement from the NEFDA, Laura Murphy will be transitioning from Board Member to Administrator role for the organization. Nancy has been with NEFDA since 2014. Laura has been the Marketing Manager for DB Roberts for just over three years and has been involved with the NEFDA for two years. Prior to her role with DB Roberts, Laura worked in Marketing for a local electrical supply distributor. She holds her MBA from UMASS Dartmouth and a BA in Communications from the University of Missouri. She is looking forward to supporting the same incredible group in a new capacity! Emails can still be directed to nefda@nefda.com. ASSOCIATION ARTICLE Bowling Party March 23,2023 We had so much fun at our Bowling Party earlier in the year. We can’t wait to get together again for this event in 2023. The 2022 Bowling party hosted over 70 attendees. Attendees enjoyed a great night of visiting fastener friends, beverages, food and bowling. We hope to see all of you there in March!!! 2023 Event Schedule January 19 March 23 June 1 Hall of Fame Inductions/Annual Meeting O’Connors Restaurant, Worcester, MA Bowling Party 34th Scholarship Golf Outing NEFDA Welcomes New Members ¤ Big Bolt, LLC ¤ Goebel Fasteners, Inc. ¤ Huyett ¤ Impact Tool Supply NEW ENGLAND FASTENER DISTRIBUTORS ASSOCIATION