Civil Engineering: Building Structures Review
Filled with solved examples and problems, and key concepts and equations, this comprehensive review guide is for civil engineers who want to prepare for the building structures topics of the PE exam.
TABLE OF CONTENTS Civil Engineering: Building Structures Review
STRUCTURAL STEEL DESIGN
Elastic Design of Steel Beams
The allowable stress on flexural members depends on the shape of the section and the bracing used to prevent lateral instability. Sections are classified as compact, noncompact, and slender in accordance with the criteria given in AISC 14 Table B5.1. Most rolled W shapes qualify as compact sections. The exceptions are indicated in the AISC Tables of Properties by denoting the value of the yield stress F ? y and F ??? y at which a particular shape becomes noncompact. The allowable bending stress for compact symmetrical shapes is given by AISC Equation (F1-1) as
when the maximum unbraced length of the compression flange does not exceed the smaller of
where b f = flange width and A f = compression flange area. When the unbraced length of a compact shape exceeds L c but is less than the greater of
the allowable bending stress is given by AISC Section F1.3 as
| where r T | = radius of gyration of the compression flange plus one-third of the web area |
| C b | = bending coefficient defined in Section F1.3 and Part 5, Table 6 |
| = 1.75+1.05 M 1/ M 2+0.3( M 1/ M 2) 2, but not more than 2.3. |
The value of C b conservatively may be taken as unity. Examples of the derivation of C b are illustrated in Fig. 18. Values of
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