tailieunhanh - Steel Designer's Manual Part 16

Tham khảo tài liệu 'steel designer's manual part 16', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Steel Designers Manual - 6th Edition 2003 This material is copyright - all rights reserved. Reproduced under licence from The Steel Construction Institute on 12 2 2007 To buy a hardcopy version of this document call 01344 872775 or go to http 1152 Notes on section dimensions and properties Z 1 y where y is the distance to the extreme fibre of the section from the elastic neutral axis. For castellated sections the elastic moduli given are those at the net section. The elastic moduli of the tee are calculated at the outer face of the flange and toe of the tee formed at the net section. For parallel flange channels the elastic modulus about the minor y-y axis is given at the toe of the section . y B - Cy where B is the width of the section cy is the distance from the back of the web to the centroidal axis. For angles the elastic moduli about both axes are given at the toes of the section . yx A cx yy B Cy Where A is the leg length perpendicular to the x-x axis B is the leg length perpendicular to the y-y axis Cx is the distance from the back of the angle to the centre of gravity referred to as the x-x axis Cy is the distance from the back of the angle to the centre of gravity referred to as the y-y axis. Buckling parameter u and torsional index x The buckling parameter and torsional index used in buckling calculations are derived as follows 1 For bi-symmetric flanged sections and flanged sections symmetrical about the minor axis only u 4Sx2 A2 h2 1 4 x A J 112 2 For flanged sections symmetric about the major axis only u IySỉr A2 H f x A H Iy J 1 2 Steel Designers Manual - 6th Edition 2003 Notes on section dimensions and properties 1153 where Sx is the plastic modulus about the major axis g 1 - 4 Ix Ix is the second moment of area about the major axis Iy is the second moment of area about the minor axis A is the cross-sectional area h is the distance between shear centres of flanges for T sections h is the distance between the