Design considerations for joining of tubular members subjected to impact loading

• Main Authors: Richard Leonard, III, Luke Luskin, Luliang Zhang, Jeffery Jinkerson, Justin Morse, Mark Horstemeyer, Haitham El Kadiri, Hongjoo Rhee, Josh Loukus, Wilburn Whittington
• Format: Article
• Language: English
• Published: Elsevier 2021-06-01
• Series: Journal of Advanced Joining Processes
• Subjects: Impact loading; Stress wave; Tube joining; Welding; Threading; Explicit finite element analysis
• Online Access: http://www.sciencedirect.com/science/article/pii/S2666330920300352

This study explores the effect of impact loading in structural bar and tube welded and threaded joints. Specifically, this work concentrates on stress wave propagation and mechanical impedance to show the effect of geometric parameters on stress distribution and history inside these joined members. In this experimental work, welded and threaded bar-and-tube networks are compared with equivalent length single bars to provide a measure of joint quality. Application to dynamic experimental equipment, known as Hopkinson Bars, is considered herein due to the stringent need for wave uniformity within these systems. Explicit finite element analysis on the experimental setup was performed to provide internal stress history information to provide more insight into the causes of stress risers and spurious load reflections. A key finding in this study shows that joint impact performance reduces when joint size is either too small or too large. This optimized joint size is found to depend on the joint'seffective mechanical impedance. This study serves as a new look at potential joining considerations under impact loading.