Page 19 - Shigley's Mechanical Engineering Design

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xvi Mechanical Engineering Design
a series of linked problems, a substantial analysis has been achieved, addressing
such things as deflection, stress, static failure, dynamic failure, and multiple
component selection. Since it comes one assignment at a time, it is no more
daunting than regular homework assignments. Many of the linked problems blend
very nicely with the transmission case study developed throughout the book, and
detailed in Chap. 18.
• Content changes. The bulk of the content changes in this edition falls into categories
of pedagogy and keeping current. These changes include improved examples, clari-
fied presentations, improved notations, and updated references. A detailed list of
content changes is available on the resource website, www.mhhe.com/shigley.

A few content changes warrant particular mention for the benefit of instructors familiar
with previous editions.
• Transverse shear stress is covered in greater depth (Sec. 3–11 and Ex. 3–7).
• The sections on strain energy and Castigliano’s method are modified in presenta-
tion of equations and examples, particularly in the deflections of curved members
(Secs. 4–7 through 4–9).
• The coverage of shock and impact loading is mathematically simplified by using an
energy approach (Sec. 4–17).
• The variable σ rev is introduced to denote a completely reversed stress, avoiding
confusion with σ a , which is the amplitude of alternating stress about a mean stress
(Sec. 6–8).
• The method for determining notch sensitivity for shear loading is modified to be
more consistent with currently available data (Sec. 6–10).
• For tension-loaded bolts, the yielding factor of safety is defined and distinguished
from the load factor (Sec. 8–9).
• The presentation of fatigue loading of bolted joints now handles general fluctuating
stresses, treating repeated loading as a special case (Sec. 8–11).
• The notation for bearing life now distinguishes more clearly and consistently be-
tween life in revolutions versus life in hours (Sec. 11–3).
• The material on tapered roller bearings is generalized to emphasize the concepts
and processes, and to be less dependent on specific manufacturer’s terminology
(Sec. 11–9).
• Streamlining for clarity to the student. There is a fine line between being compre-
hensive and being cumbersome and confusing. It is a continual process to refine
and maintain focus on the needs of the student. This text is first and foremost an
educational tool for the initial presentation of its topics to the developing engi-
neering student. Accordingly, the presentation has been examined with attentive-
ness to how the beginning student would likely understand it. Also recognizing
that this text is a valued reference for practicing engineers, the authors have en-
deavored to keep the presentation complete, accurate, properly referenced, and
straightforward.

Connect Engineering

The 9th edition also features McGraw-Hill Connect Engineering, a Web-based assign-
ment and assessment platform that allows instructors to deliver assignments, quizzes,
and tests easily online. Students can practice important skills at their own pace and on
their own schedule.