Experiment And Analysis Of Hexagon-hole Hybrid Castellated Beams

The hybrid castellated beams is that applying the combination with different strength grades of steel.The material properties can be fully utilized,simultaneously the structural weight and project cost will be economized by adopting the two types of steel legitimately.The orthogonal test method has the characteristics of using representative test to reflect the overall trend.In this paper,using the orthogonal method to carry out the experiment.Analysis of range are used for experimental results to find the key factors affect the quality of steel and to obtain excellent level.The analysis shows that all the factors on the hybrid castellated beams wing critical elastic local buckling stress from high to low in turn for height-thickness ratio,width-to-thickness ratio,diameter-depth ratio,upper flange strength.The height-thickness ratio and width-to-thickness ratio has a greater impact.The diameter-depth ratio and upper flange strength has a minor effect.Through strain analysis on the web of the test beam we can find that the normal stress distribution of the real Web cross section is nonlinear.It is different to Vierendeel Truss method.To simplify the rigidity of hexagonal holes castellated beams with the principle of definite integral mean value theorm.By using the equivalent bending stiffness to deduce simplified calculation formula of deflection and strength.Meanwhile,the calculation methods of the deflection and strength of the commonly used castellated beams at home and abroad are summarized.With the Japanese formula,Vierendeel Truss formula,the standard formula and the measured value is compared,it shows that this formula has high practical value.