Method Of Horizontal Elliptical Holes Cellular Beam-like Production And Design Calculations

Castellated steel beams can save amount of materials and facilitate passage of pipes, high capacity being of practical value for engineering application. However, castellated beams are not classical members which accord with Bernoulli's assumption of section remaining plane. Their design remains unsatisfactorily solved. There is no technical standard for castellated beams in China. Therefore, it is necessary to further study. In this paper, how to account for the effect of the geometry parameter of openings in design is investigated with reference to oblong-castellated beams. The main content is as follows:1. Introduced fabrication process of oblong- castellated.2. A methodology is put forth to determine the equivalent flexural stiffness of castellated beams, which is reversely derived from the results of finite element analysis (FEA) of oblong-castellated beams under pure bending. It is simple, accurate, economical, and high efficient. A rational formulation is presented to calculate the equivalent flexural stiffness of oblong-castellated, in which the reduction coefficient of stiffness for web with openings is obtained by FEA for various cases of opening and expressed by a half-empirical equation for web with oval holes. The deficiencies in the stiffness calculation implied in the existing approaches of deflection prediction are pointed out by comparison with the results of stiffness determined here in this paper.3. On the basis of Vierendeel analogy to open web truss, the expression of deflection is derived for oblong-castellated beams. Then it is used to evaluate the deflection of oblong-castellated beams and the relevant parameters are given by correlation to the FEA results.4. Expression of critical bending moments for flexural-torsional buckling are derived by equilibrium method and energy method for castellated beams with the opening of oblong- castellated under typical loading. The relevant stiffnesses are determined. The result of these formulae is verified by good coincidence with the FEA results.