Gantry crane structure analysis due to surveying the possibility of the crane productivity increasing

The crane has been checked for the possibility to operate with the maximum lifting load of 40t at all outreaches. According to the Manufacturer the maximum outreach for SWL 40 t has been restricted up to 25 meters.

Performed checks:

  • Structural static, fatigue and buckling strength;
  • Hinges and bearings;
  • Crane stability;
  • Increased slewing column wheel load;
  • Check of increased force in rack of luffing mechanism;

As consequence, recommendations regarding the elements of the structure to be reinforced are given

Static strength

Crane stability
Has been checked acc. FEM 1.001 for several Load Cases

Wheel load calculation
The upper structure has been turned with some increment angle and for each case the wheel load has been calculated

Slewing column wheel load check using strain gauge measurements

The tarring curve has been created to convert the measured deformation of the strain gauge on the wheel To the force caused this deformation.

The problem of the reliable wheel load determination appears in the cases when the crane parameters i.e. outreach, SWL are planning to be changed and based on the obtained wheel load the quay side strength, crane stability is checked.

For the proper wheel load calculation the dead weights of the crane structure and their COG positions are needed. But very often this information is missing (drawings could not be founded, the COG of the elements are not shown in the documents, etc.)

In order to solve this issue we are using strain gauge measurements of the wheel load with further translation of the deformation to the force units.

Benefits of this approach:
Reliable, quite fast, no additional information regarding weights/COG positions is needed.

Check of increased force in rack of luffing mechanism for additional counterweight determination