Preloaded Joint Analysis Methodology

In Preloaded Joint Analysis Methodology, you'll learn ...

• Bolt, nut, and screw geometry & terminology standard in the industry as applied to the typical bolted joint
• Eight major concepts covering the loads, the corresponding failure modes, and the methodology used to calculate the respective values and, ultimately, the margin of safety of fasteners
• Application of the analysis to four common bolted joint configurations as presented in four respective examples

Overview

Preview a portion of this course before purchasing it.

Credit: 3 PDH

Length: 46 pages

Much of the material presented here was first compiled in NASA Technical Memorandum 106943, Preloaded Joint Analysis Methodology for Space Flight Systems. Chambers, 1995 [1]. This is one of the best compilations and explanations of the bolted joint, having pulled many of the equations from Shigley & Mischke: Mechanical Engineering Design [2] and Bruhn, E. F.; Analysis and Design of Flight Vehicle Structures [3].

However, all stop short of putting everything together in a cookbook manner to guide the engineer through a complete and combined analysis. This course intends to review the methods for joint analysis and correct that with a recipe and examples in the final section.

As we begin this course, the reader will first review the bolt, nut, and screw geometry & terminology standard in the industry as applied to the typical bolted joint. Next, we will dive into eight major concepts covering the fastener loads, the corresponding failure modes, and the methodology used to calculate the respective values and, ultimately, the margin of safety.

Along the way, we will explore the derivation of several of these equations. Finally, we will put it all together by applying the analysis to the four common bolted joint configurations as presented in four respective examples. These examples will provide an excellent “go-by” from which the reader can either perform the calculations by hand or develop their own Excel, MathCAD, or other software-based models for repeated analytical use.

Learning Objectives

Upon completion of this course, participants will be able to:

• Identify bolt, nut, and screw geometry and terminology.
• Explain the fundamentals and purpose of a preloaded joint.
• Describe variations in joint stiffness and elasticity for different configurations.
• Identify common modes of failure within a fastener.
• Explain common modes of failure of the fastened material.
• Describe the criteria for joint gapping.
• Identify the failure modes of nuts and threaded inserts.
• Determine the applicable preload and corresponding torque.
• Explain the effects of lubricants and locking features on preload torque selection.
• Describe the effects of temperature and relaxation on preload.
• Apply the relevant equations to analyze preloaded joints using the two provided examples.

Certificate of Completion

You will be able to immediately print a certificate of completion after passing a multiple-choice quiz consisting of 20 questions. PDH credits are not awarded until the course is completed and quiz is passed.