AS 5222 pdf download

AS 5222 pdf download.Cranes — Wind load assessment (ISO 4302:2016, MOD)
1  Scope
This International Standard specifies the assessment of wind loads on cranes. It establishes general methods for calculating wind loads (for in-service and out-of-service conditions), which are included in the load combinations stated in ISO 8686-1 and used for proofs of competence such as those given in ISO 20332 for the structural components of cranes. It provides a simplified method of calculation and assumes that — the wind may blow horizontally from any direction, — the wind blows at a constant speed, — there is a static reaction to the wind load applied to the crane structure. It includes built-in allowances for the effects of gusting (fluctuation in wind speed) and for dynamic response. It gives guidance on when to secure the crane for out-of-service conditions.
3  Terms, definitions, symbols and abbreviated terms
For the purposes of this document, the following terms and definitions apply. The main symbols are given in Table 1. 3.1 in-service wind maximum wind that the crane is designed to withstand under operating conditions 3.2 out-of-service wind maximum (storm) wind blowing from the least favourable direction that a crane is designed to withstand when in an out-of-service condition
5  In-service wind
5.1  General The wind loading shall be applied in the least favourable direction in combination with the appropriate loads as defined in ISO 8686-1:2012, load combinations B and C. In-service design wind speeds and corresponding pressures shall be either selected based on Table 2 or specified based on the crane configuration, application and the wind conditions. The in-service design wind speed shall be documented in the operating manual of the crane.The wind speed shall be measured at the highest point of the crane. The in-service design wind speed in Table 2 is based on the premise that the crane can be fully secured in an out-of-service configuration before the design wind speed is exceeded. As the means for this securing vary by crane type and configuration, the time allowance (e.g. locking devices at special locations of the crane runway, hand- operated or automatic rail clamps) shall take this into account by a lower level of wind speed chosen to start the securing. Wind speeds for the use of different crane configurations and for the starting of securing shall be specified. 5.2  Action of in-service wind on suspended load On all cranes, the action of the wind on the load must be taken into account and the method by which this is done shall be clearly described. This may be accomplished by use of wind loads on load parameters of size and shape. 5.4  Shape coefficients for individual members, frames, etc Shape coefficients, C f , for individual members, single lattice frames, and machinery houses, etc. vary according to the aerodynamic slenderness and, in the case of large box sections, with the section ratio. Aerodynamic slenderness and section ratio are defined in Figure 1. Where a frame is made up of flat-sided and circular sections, or of circular sections in both flow regimes (D × v s < 6 m 2 /s and D × v s ≥ 6 m 2 /s, with D the diameter of a circular section in metres, and v s the design wind speed in metres per second, the appropriate shape coefficients are applied to the corresponding frontal areas.5.5  Shielding factors — Multiple frames or members Where parallel frames or members are positioned so that shielding takes place, the wind load on the windward frame or member and on the unsheltered parts of those behind it are calculated using the appropriate shape coefficients. The shape coefficients on the sheltered parts are multiplied by a shielding factor, η, given in Table 4. Values of η vary with the solidity and spacing ratios as defined in Figure 2.