Calculation of crane capacity charts with Eager.sterk

Cranes are getting higher with increased slenderness as a result. What does this mean for the determination and calculation of the crane capacity? Since the 2^nd order effect increases for slender (high) cranes, calculations get more complex and more time consuming due to its non-linear (cyclic) character.

2^nd order effect? What is that?

• Additional loads on the crane induced by geometrical changes
• Additional side-ward bending moment due to change of shape
• Additional longitudinal bending due to change of shape

For every boom-, jib length and lifting radius it requires a cyclic (nonlinear) calculation to predict the deformations. Historically these calculations are done by “nonlinear” FEM (finite element method).  However, this is not a quick process, especially when it comes to many different configurations of a crane.

Therefore, to speed up this process Eager.one has developed a hand written code, applicable to run different configurations at the same time, without the need for re-modelling.

Eager.sterk© calculates your crane capacity charts

Eager.sterk© is our in-house design software to calculate capacity charts for all kinds of cranes, independent from any brand.

The software consists of 6 parts:

1. A calculation code
2. Description of the validation of the STERK© code with STERK©. (Free to look into, for third parties)
3. Interpretation of STERK© source code, using STERK© during the making of ratings
4. Spreadsheet for completely describing the crane (pre-processing);
   Every cell has a graphical remark to guide the STERK© user.
5. Spreadsheet for complete description of the ratings (post-processing);
   Every load chart value (SWL@Radius) has a remark, describing the critical issue (strength, stability, etc.);
   For every rating-position or configuration a graphical output of the crane can be generated.
6. Complete summary of all results for a single load chart position (SWL@radius), including:
   • Deflections
   • Stresses
   • Bending moments
   • Shear forces

Different configurations

Upgrade of capacity charts for mobile and offshore cranes

Do you need 10-15% more capacity in the chart? We can help you!

Our engineers work with STERK© to calculate the limits in crane design. We will research your crane structure in order to find the weakest spot. With this information we can advise you for reinforcements of the crane to increase the strength. This maximizes the crane capacity within the required safety standards.

Interested to learn more about STERK©?

Please download our presentation using the button below or contact us. We would be happy to discuss your specific situation.

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