**10. Significant contributions**

The research underlying this chapter is a pioneering effort for understanding electric rope shovel dipper stress analysis using dynamic resistive forces. The research results contribute to the existing body of knowledge on health and longevity of shovel dipper-teeth assembly. It advances shovel reliability, maintainability, and availability, which influence surface mining productivity. Previous research generally ignored the dynamic forces due to the weight of the dipper and payload. Given the size of current large shovels with 100+ tons per pass, these forces must be accounted for in any meaningful and comprehensive dynamic model. The research models provide detailed information on the forces and torques for all joints and links within the shovel front-end assembly. This research is also the first attempt to model the fatigue life of the shovel dipper-teeth assembly. It lays a foundation for understanding dipper fatigue failure resulting from high stress intensity, crack initiation, and propagation for rope shovel front-end assembly. Research shows that dipper-related breakdowns are among the highest for shovel excavation downtimes [4]. The current maintenance practice for the shovel frontend assembly is based on experience rather than science. This chapter lays a foundation for

<sup>1</sup> Crack length in this text (and in literature) is always referred as half of the total length of crack. A critical length of 100 mm would be 200 mm total length of the crack.

the scientific modeling and understanding of the shovel dipper-teeth stress and fatigue failure studies. The life expectancy of the shovel components should help reduce the operating costs of shovel excavation. Overall, the study contributes to the health and longevity of the large rope shovels by providing a more scientific basis to the subject matter and should be helpful in the design and development of the next generation of excavators. The results of these models can be used to design and build the next generation of shovel dippers for the surface mining industry and advance frontiers and knowledge in shovel dipper stress and fatigue failure modeling.
