TABLEOFCONTENTS
CHAPTER1 INTRODUCTION..3.3VIERENDEEL BENDING IN COMPOSITE 1.1HISTORY.1BEAMS 1.2MANUFACTURING.3.3.1Calculation of Axial Force 1.3NOMENCLATURE.2and Vierendeel Moment at 1.4INTRODUCTION OF DESIGN GUIDE..3Each Opening......
3.3.2Calculation of Vierendeel Bending CHAPTER 2 USE OF CASTELLATED AND Moment of the Upper and CELLULAR BEAMS .. Lower Tees
3.3.3 Calculation of Available Axial and 2.1GENERAL.5Flexural Strength of Top and 2.2APPLICATIONS AND ADVANTAGES.5Bottom Tees. 2.2.1Parking Structures. . . ..53.4WEB POST BUCKLING. 2.2.2Industrial Facilities.63.4.1Web Post Buckling in 2.2.3Servicc/HVAC Integration.6Castellated Beams.19 2.2.4Construction Efficiency.63.4.2Web Post Buckling in 2.2.5Vibration Resistance.7Cellular Beams. .21 2.2.6Asymmetric Sections. ..73.5HORIZONTAL AND VERTICAL SHEAR.22 2.2.7Aesthetics.73.5.1 Calculation of Available Horizontal 2.3WEB OPENING SIZE AND SPACING Shear Strength .22 AND TYPICAL CONNECTIONS..83.5.2 Calculation of Available Vertical 2.3.1End Connections..8Shear Strength.22 2.3.2Inflling of Openings ..83.6LATERAL-TORSIONAL BUCKLING.23 2.3.3 Large Copes..93.7DEFLECTION.23 2.4SPECIAL CONSIDERATIONS..9CONCENTRATED LOADING.23 2.4.1Concentrated Loads..9 2.4.2Depth-Sensitive Projects. .9CHAPTER4DESIGNEXAMPLES.....25 2.4.3Erection Stability.94.1NONCOMPOSITE CASTELLATED 2.4.4Fireproofing..10BEAM DESIGN..25 2.45sass Sue4.2NONCOMPOSITE CELLULAR CHAPTER3 DESIGN PROCEDURES11BEAM DESIGN..40
4.3COMPOSITE CASTELLATED 3.1INTRODUCTION I1 BEAM DESIGN..55 3.2VIERENDEEL BENDING IN4.4COMPOSITE CELLULAR NONCOMPOSITE BEAMS . BEAM DESIGN...78 3.2.1Calculation of Axial Force and Vierendeel Moment at Each Opening . . SYMBOLS101 3.2.2Calcuation of Available Axial (Tensile/ Compressive) and Flexural Strength of REFERENCES.103 Top and Bottom Tees . . 3.2.3Check of Top and Bottom Tees FURTHER READING..105 Subjected to Combined Flexural and Axial Forces ..15
Chapter1 Introduction
1.1HISTORY manufacturing a castellated beam is presented in Figure 1-1. The idea of creating single web openings in wide-flange Once the section has been cut n the appropriate pattem (a). steel beams in order to pass service lines through the beam the two halves are offset (b). The waste at the ends of the stems back to the early use of steel sections. The design beam is removed (c), and the two sections are welded back of beams with web openings is addressed in AISC Design together to form the castellated section (d). A full or partial Guide 2. Design of Steel and Composite Beams wizh Web penetrationbutt weld is then typicallymade froone sideof Openings, which explicitly notes that the design provisions the web, without prior beveling of the edges if the web thick- seu ness is relatively small. A photograph of the manufacturing so an p e soos qmprocess of a castellated beam is shown in Figure 1-2. 1990). In this document, castellated beams are defined asCellular beams are fabricated in a similar manner using a steel beams with expanded sections containing hexagonal nested semicircular cutting patern In order to achieve the openings. Cellular beams are defined as expanded steel sec- repeating circular pattern, two cutting passes are required, tions with circular openings. as shown in Figure 1-3. The two cutting passes increase Beams with expanded web sections with repeating web the handling of the steel during the manufacturing process; openings were first used in I910 by the Chicago Bridge and consequently, the time to produce a cellular beam is slightly Iron Works (Das and Srimani, 1984). This idea was also greater than that of a castellated beam. The cuts are made in developed independently by G.M. Boyd in Argentina in 1935 a circular patterm instead of the zigzag used for the castel- and was later patented in the United Kingdom (Knowles. lated beams. The circular cutting produces additional waste 1991). In the 1940s, the use of castellated and cellular beamsas pared to castellated beams, as shown in Figure 1-3(b). increased substantially, in part due to the limited number Once the two cuts have been made, the two halves that have of structural sections that the steel mills could fabricate in been created are offset and welded back together to form a Europe. Steel mills could efficiently produce a number of cellular beam. A photograph of the manufacturing process of larger section sizes by manually expanding beams because of a cellular beam is presented in Figure 1-4. low labor-to-material cost ratios. However, steel mills in the United States did not experience the same section limitations and low labor costs as the mills in Europe: consequently, the Cut ine fabrication of such beams was not economically efficient. As a result, the use of castellated and cellular beams diminished until automated manufacturing techniques became avail-(a) able. The improved automation in fabrication, coupled with the need for architects and structural engineers to search for more efficient and less costly ways to design stee...
