Systems Engineering - ATI

Design and Analysis of Bolted Joints
For Aerospace Engineers
Recent attendee comments ...
“It was a fantastic course—one of the
most useful short courses I have ever
taken.”
“A must course for structural/mechanical
engineers and anyone who has ever
questioned the assumptions in bolt analysis”
(What I found most useful:) “strong
emphasis on understanding physical
principles vs. blindly applying textbook
formulas.”
“Excellent instructor. Great lessons
learned on failure modes shown from
testing.”
Summary
Just about everyone involved in developing
hardware for space missions (or any other purpose,
for that matter) has been affected by problems with
mechanical joints. Common problems include
structural failure, fatigue, unwanted and unpredicted
loss of stiffness, joint shifting or loss of alignment,
fastener loosening, material mismatch, incompatibility
with the space environment, mis-drilled
holes, time-consuming and costly assembly, and
inability to disassemble when needed.
• Build an understanding of how bolted joints
behave and how they fail.
• Impart effective processes, methods, and
standards for design and analysis, drawing on a mix
of theory, empirical data, and practical experience.
• Share guidelines, rules of thumb, and valuable
references.
The course includes many examples and class
problems; calculators are required. Each participant
will receive a comprehensive set of course notes.
subject to strict application of modern science.
Instructor
Tom Sarafin has worked full time in the space
industry since 1979, at Martin Marietta and Instar
Engineering. Since founding Instar in 1993, he has
consulted for DigitalGlobe, AeroAstro, AFRL, and
Design_Net Engineering. He has helped the U. S.
Air Force Academy design, develop, and test a
series of small satellites and has been an advisor to
DARPA. He is the editor and principal author of
Spacecraft Structures and Mechanisms: From
Concept to Launch and is a contributing author to all
three editions of Space Mission Analysis and
Design. Since 1995, he has taught over 150 short
courses to more than 3000 engineers and
managers in the space industry.
December 7-9, 2010
Beltsville, Maryland
$1590 (8:30am - 5:00pm)
"Register 3 or More & Receive $100 00 each
Off The Course Tuition."
Course Outline
1. Overview of Designing Fastened Joints.
Common problems with structural joints, a design
process, selecting the method of attachment, strength
analysis for sizing and assessment, establishing
design standards and criteria.
2. Introduction to Threaded Fasteners. Brief
history of screw threads, terminology and specification,
tensile-stress area, fine threads vs. coarse threads.
3. Developing a Concept for the Joint. Selecting
the type of fastener, configuring the joint, designing a
stiff joint, shear clips and tension clips, guidelines for
using tapped holes and inserts.
4. Calculating Fastener Loads. How a preloaded
joint carries load, temporarily ignoring preload, other
common assumptions and their limitations, calculating
bolt loads in a compact joint, examples, calculating
fastener loads for skins and panels.
5. Failure Modes, Assessment Methods, and
Design Guidelines. Typical strength criteria for
aerospace structures; an effective process for strength
analysis; bolt tension, shear, and interaction; tension
joints, shear joints, identifying potential failure modes,
riveted joints, fastening composite materials.
6. Thread Shear and Pull-out Strength. How
threads fail, computing theoretical shear engagement
areas, including a knock-down factor, selected test
results.
7. Selecting Hardware and Detailing the Design.
Selecting hardware and materials, guidelines for
simplifying assembly, establishing bolt preload, locking
features, recommendations for controlling preload.
8. Detailed Analysis: Accounting for Bolt Preload.
Mechanics of a preloaded joint, estimating the load
carried by the bolt and designing to reduce it, effects of
ductility, calculating maximum and minimum preload,
thermal effects on preload, fatigue analysis.
9. Recommended Design Practice for Ductile
Bolts Not Subject to NASA Standards. Applicability,
general recommendations, torque coefficients for steel
fasteners, establishing allowable limit bolt loads for
design, example.
10. Complying with NASA Standards. Factors of
safety, fracture control for fastened joints, satisfying the
intent of NSTS 08307A, simplifying: deriving reduced
allowable bolts loads, example.
42 – Vol. 104 Register online at www.ATIcourses.com or call ATI at 888.501.2100 or 410.956.8805