Life Prediction in an Overhead Crane

THE PROBLEM

View of overhead crane from below

View of overhead crane from below.

Many large-scale industrial processes require scheduled maintenance and repairs.  Industrial repair is costly and can often be dangerous due to environmental hazards such as height. The application of modern computational methods such as Finite Element Analysis can reduce the costs and dangers of scheduled maintenance.  United States Steel Corporation (U. S. Steel) has asked CIVS to apply these methods to an essential piece of equipment: an overhead charging crane.  By using numerical analysis, future inspections can be made safer and more efficient.  


Simulation results showing distribution of stress.

Simulation results showing distribution of stress

THE PROJECT

Using drawings provided by U. S. Steel, 3D models of the crane assembly were created.  Additional models were created by including the damage discovered and repaired during previous inspections, such as cracking.  By applying real-world conditions to the numerical model, the distribution of stresses throughout the equipment could be observed.  With these results, the life of the equipment was calculated using Fatigue Analysis Life Prediction methods.  The Fatigue Analysis uses knowledge of material properties, how frequent the stresses are applied, and the magnitude of the stresses to determine the remaining life of the equipment.  The model was validated by comparing the results of the undamaged model with the known damage from future cases.


THE OUTCOME

This project allowed for the isolation of key areas within the entire crane assembly, all of which featured high stress concentration or low predicted life.  A Virtual Reality visualization of the simulations was used by U. S. Steel to provide a more intuitive understanding of the simulation results and location of the key areas.  The project allowed U. S. Steel to improve the efficiency and safety of future inspections and to determine the necessity of the redesign of specific parts of the crane assembly.  The methodology developed during this project can now be applied to other equipment at any U. S. Steel facility. The project provided direct economic impact through annual cost avoidances for recurring structural repairs, downtime and lost production. 

another view of the integration of cracking and comparison of stress distribution

Integration of cracking and comparison of resulting stress distribution.

Two Virtual Reality views of Integration of cracking and comparison of resulting stress distribution


Sponsor: United States Steel Corporation
Industrial Collaborator: George Cingle III, Director Engineering Project Development

 Download a PDF of the Crane project flyer

Download Crane Flyer