Page 247 - Handbook of Materials Failure Analysis

CHAPTER

A reliable analysis method

for estimating large 10

excavator structural

strength

†
Ying Li*, Yong-An Tian , Samuel Frimpong {
*
Bucyrus International Inc., Houston, TX, USA
†
Beijing Sevenstar Electronics Co., Beijing, China
{
University of Missouri-Rolla, Rolla, MO, USA
CHAPTER OUTLINE

1 Introduction ..................................................................................................... 243
2 Shovel Structure and Operation Process ............................................................ 246
2.1 Structure Description .......................................................................246
2.2 Operation Description .......................................................................246
3 Structural Dynamics Analysis Method of Shovel Front-End Mechanism ................ 248
3.1 Finite Element Modeling of Front-End Structure .................................248
3.2 Dynamics Loading of Front-End Structure ..........................................249
3.3 Equivalent SR and Life Estimation of Front-End Structure ...................249
4 Results and Discussion ..................................................................................... 252
4.1 Simulation and Validation of Front-End Model ....................................252
4.2 Shovel Front-End Fatigue Life Prediction ...........................................254
5 Conclusion ....................................................................................................... 256
Nomenclature ........................................................................................................ 256
Acknowledgments .................................................................................................. 257
References ............................................................................................................ 257

1 INTRODUCTION
Large excavators such as the mining dragline (Figure 10.1a) and shovel
(Figure 10.1b) are used for surface mining to dig and transport overburden
[1–10]. Their large size front-end structures can swing either left or right during
working. The repeated loading induces the front-end to undergo fatigue loading
as a result of significant cracking at welded connections [10,11] and fatigue failure
as simulated in Figure 10.2. It is estimated that 90% of structural failures in large
excavators are due to fatigue alone. Several decades ago, the boom of Peabody
Coal Company’s Marion 8750 failed during operation at the Black Mesa Mine

Handbook of Materials Failure Analysis With Case Studies from the Chemicals, Concrete, and Power Industries. 243
http://dx.doi.org/10.1016/B978-0-08-100116-5.00010-7
Copyright # 2016 Elsevier Ltd. All rights reserved.