This is how the structural design of crane runway girders works
Although crane runway girders are considered simple, static systems in essence, they are at the same time dynamically stressed components that are subject to scheduled torsional loading. With the powerful S9+ programme, FRILO therefore offers a powerful solution that takes into account the special requirements for the complex calculation of steel crane runway girders.
The dynamic loading of crane runway girders and the simultaneously occurring planar torsion lead to two essential requirements for the verification of crane runway girders. On the one hand, serviceability and structural safety verifications must be carried out taking into account arching torsion. On the other hand, the decrease in the stressability of the material as a result of the numerous load changes that occur must be taken into account in the design. In addition, the required local verifications, e.g. the local stability failure under the crane wheels, represent an increased demand on the structural engineers.
The verification in S9+
In order to meet these requirements adequately, the FRILO programme S9+ offers structural engineers the possibility to calculate steel crane girders reliably, quickly and comprehensively. It is tailored to the special requirements of verification and therefore helps to noticeably reduce the time and effort required for the complex design of crane runways. The calculation of internal forces, deformations and stresses with pre-deformations is carried out according to the bending torsion theory II. The calculation of internal forces, deformations and stresses with pre-deformations is carried out according to the second-order bending torsion theory. In addition to verifications for ultimate limit states and serviceability, fatigue strength verifications can also be carried out according to EN 1993-6. Buckling verifications according to the method of effective cross-sections and verifications of the local wheel load introduction at the upper or lower chord can also be carried out.
Wide range of modelling options for system input
The S9+ impresses with its diverse modelling options. From single-span girders to multi-span girders with or without joints, different static systems can be designed. Bridge and suspension cranes as well as monorail bottom flange trolleys with one or two independently operated cranes are available as crane systems. Once the appropriate crane system has been selected, discrete bearing conditions, joints and buckling stiffeners can be defined along the crane runway girder, the overall length of which is specified. This makes any bearing arrangements possible, taking into account horizontal bracing braces. Depending on the crane system, rolled sections or user-defined, single as well as double symmetrical cross-sections with and without reinforcement by top chord angles can be selected.
Automatically generated presets can be changed
The FRILO solution allows the calculation of up to two independently operated cranes of lifting classes HC1 to HC4 as well as load groups according to EN 1991-3 S0 to S9. From the crane parameters entered, the S9+ automatically derives dead weight, vertical wheel loads and horizontal side loads as actions on the crane runway. The horizontal side loads of bridge cranes are calculated by the programme according to EN 1993-3. Load cases and crane crossings are also automatically generated by the programme with the corresponding vibration and partial safety factors. In addition, the necessary pre-deformations for calculating the internal forces according to bending torsion theory II. In addition, the pre-deformations required for calculating the internal forces to the second order bending torsion theory in the individual crane runs are already automatically determined by the S9+. In special cases, users have the option of editing and supplementing the load cases generated by the programme as well as the crane crossings. By entering other variable loads, a restriction to certain crane systems can be circumvented. In addition, wind and earthquake loads can be taken into account. Structural engineers can also directly influence the automatically generated action combinations.