Method for determining load on power shovel member
A method of determining a load on at least one member of a power shovel may include the steps of: sensing a strain in a boom of the power shovel; determining a plurality of member joint loads based on strain sensed in the boom; and determining the load on the at least one member of the power shovel from the plurality of member joint loads.
1. A method of determining a load on at least one member of a power shovel, comprising:
sensing a strain in a boom of the power shovel;
determining a plurality of member joint loads based on strain sensed in the boom;
performing fatigue analysis from the plurality of member joint loads by at least:
converting the plurality of member joint loads into equivalent axial loads and bending moments;
applying a cycle counting algorithm to the equivalent axial loads and bending moments to reduce a spectrum of varying axial loads and bending moments into a set of axial load and bending moment reversals;
from material and geometry data for the power shovel, mapping a magnitude of elastic stress (S) against number of cycles (N) to material failure, resulting in an S-N curve; and
estimating fatigue life of the at least one member from the set of axial load and bending moment reversals and the S-N curve;
determining the load on the at least one member of the power shovel from the plurality of member joint loads resulting in a calculated load; and
using a controller operatively associated with the power shovel to control power shovel operation by utilizing at least the calculated load.
2. The method of claim 1 , further comprising determining a hoist rope tension from strain sensed in the boom.
3. The method of claim 1 , further comprising determining a suspension rope tension from strain sensed in the boom.
4. The method of claim 3 , further comprising determining a boom jacking condition from the suspension rope tension.
5. The method of claim 1 , further comprising determining a hoist rope tension from strain sensed in a sheave pin of the power shovel.
6. The method of claim 1 , further comprising determining a suspension rope tension from strain sensed in a back stay of the power shovel.
7. The method of claim 6 , further comprising determining a boom jacking condition from the suspension rope tension.
8. The method of claim 1 , further comprising estimating damage from the set of axial load and bending moment reversals and the S-N curve.
9. The method of claim 1 , wherein applying a cycle counting algorithm comprises applying a Rainflow counting algorithm.
10. The method of claim 1 , further comprising performing a durability analysis based on the plurality of member joint loads.