Data introduction. Bridge cranes |
The issues surrounding the introduction of the bridge crane is varied and many articles have been published regarding the matter. In this case, the most simple case is going to be explored: a bridge crane in a warehouse consisting of a single symmetrical bay, although the process will be explored for a two bay warehouse. For a warehouse consisting of one symmetrical bay, the introduction could be resolved in the following manner:
If there are two adjacent warehouses, and symmetrical, it may be resolved in the following manner: The loads of the left bridge assigned to a live load loadcase called LL1, for example, and those of the right bridge to another live load loadcase LL2. As an additional comment, to simply mention that the various live load loadcases are combined amongst one another, by default, (although this can be reconfigured). Therefore, a combination always exists which adds the simple live load loadcases that have been defined. This is not the case for simple wind loadcases; these are independent. Having said this, a central frame of the warehouse is analysed in four separate files, without the rest of the structure.
Of course, each file must have the corresponding wind loads applied. The results of the worst case sections, footings, baseplates, etc. of the four files are those which must be used. The longitudinal braking of the bridges is also resolved independently. Regarding the runway beam. In a similar manner, the user will have to create as many independent files as there are positions to be studied along the beam. In each file, the reactions of the two wheels of the bridge crane trolley have to be applied in the same live load loadcase. |