Minor support beams

In large-diameter (> 10 to 12 ft) columns, one or more mqjor support beams (Fig. 7.1) are required, and these also support the minor support beams. In smaller-diameter (< 10 to 12 ft) columns, major support beams are often omitted, and trays are entirely supported by the support rings and minor support beams. In some cases, tie-rods are used for minimizing tray deflection. 

Support beams must be installed level, or tray levelness may be difficult to achieve, especially in large columns. Support beams are often equipped with levelling screws (288) to permit on-site levelling. A less satisfactory alternative is using slotted holes on the joint of a major support beam to its shell support brackets. Slotted holes, however, are often used on the joints of minor beams to the major support beam to allow levelling. 

Longitudinal tension and compression moduU Shear modulus In-plane shear modulus Second moment of area Major and minor axis second moments of area Span of simply supported beam Longitudinal tension and compression strengths Longitudinal in-plane shear strength Mid-span deflection Point load Shear stiffness ratio... 

The ratio between the major (ej) and minor ( 2) ellipse axes is determined by the tilt angle, i.e. the angle between the texture support plane and the plane normal to the electron beam (Fig. 6b). The tilting angle (p can be calculated from ... 

Minor beam -- - support clamp Peripheral ring clamps (Note Slotted tray is frictionally held to promote breathing) Subsupport tray ring (used with angle ring)... 

Recommendations (1) to (6) are for major-axis and (7) and (8) are for minor-axis connections. The beam is assumed to have rigid supports and vertical uniform loading only. 

Three-point bending tests were carried out on the WF-section beam and column members of the frame. Each WF-section member was simply supported on 25 mm diameter steel rollers (only one of which was free to roll) and loaded by a vertical line load at mid span. Both major and minor... 

Again, the three cycles used in this example produce very similar results, indicating again the presence of a single minimum. The reinforcement ratios for the columns are almost identical, while cycle 1 and cycle 2 show slight differences between the ratios for the beam at mid-span and over the supports. These differences, however, translate into minor differences in the weight of the steel reinforcement, while the prescribed reliability levels are always satisfied. 

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