Web Yielding and Web Crippling腹板屈服和腹板压跛.docVIP

外文翻译 Web Yielding and Web Crippling ——Come from Applied Structural Steel Design (Fourth Edition)，TSINGHUA UNIVERSITY PRESS. A beam that is subjected to concentrated loads applied normal to the flanges and symmetric to the web must be checked to ensure that a localized failure of the web does not occur. The ASDS, Section Kl, establishes requirements for beam webs under compression due to concentrated loads. When the stipulated requirements are exceeded, the webs of the beams should be reinforced or the length of bearing increased. Two conditions are considered: web yielding and web crippling. Figure 4-25 illustrates the type of deformation failure expected. Practical and commonly used bearing lengths N are usually large enough to prevent this type of failure from occurring. With respect to web yielding, the ASDS, Section K1.3, requires that the compressive stress at the toe of the fillet, shown in Figure 4-26, not exceed 0.66 .The assumption is made that the load spreads out so that the critical area for stress, which occurs at the toe of the fillet, has a length of (N + 2.5k) or (N + 5k) for end reactions and interior loads, respectively, and a width of . The dimension k, which locates the toe of the fillet, is tabulated for various shapes in the ASDM, Part 1. The controlling equations for web yielding are as follows: 1. For interior loads (defined as applied at a distance from the end of the member that is greater than the depth d of the member), ASDS Eq.(K1-2) FIGURE4-25 Web yielding/web crippling 2. For end reactions, ASDS Eq.(K1-2) where R is the applied concentrated load and N is the length of bearing. Should the web yielding stress be excessive, the problem may be corrected by increasing the bearing length ,by designing bearing stiffeners (discussed in Section 5-6 of this test), or by selecting a beam with a thicker web. With respect to web crippling , the ASDS , SectionK1, places limits on the compressive concentra