[23] W。J。 Zong, T。 Sun, D。 Li, K。 Cheng, Y。C。 Liang, FEM optimization of tool geometry based on the machined near surface’s residual stresses generated in diamond turning, Journal of Materials Processing Technology 180 (2006) 271-78。

[24] H。K。 Tönshoff, W。 König, Machining of holes, developments in drilling technology, Ann。 CIRP 43 (1994) 551-561。

[25] S。 Delijaicov, Experimental modeling of residual stress in the turning process of the DIN 100Cr6 hardened steel and it’s correlations with the cutting forces, PhD Thesis, Escola Politecnica - USP, S。 Paulo, Brazil, 176, 2004 (in Portuguese)。

[26] E。C。 Bordinassi, Superficial integrity analysis  in  a super duplex stainless steel after turning, PhD Thesis, Escola Politecnica - USP, S。 Paulo, Brazil, 155, 2006 (in Portuguese)。

[27] E。C。 Bordinassi, M。 Stipkovic Filho, G。F。 Batalha, S。 Delijaicov, N。B。 de Lima, Superficial integrity analysis in a super duplex stainless steel after turning, Journal of Achievements in Materials and Manufacturing Engineering 18 (2006) 335-38。

[28] I。 C。 Noyan, J。 B。 Cohen, Residual Stress, measurement by diffraction and interpretation, Springer Verlag。 New York, USA, 1987。

[29] G。 E。 Box, W。 G。 Hunter, J。 S。 Hunter, Statistics of experiments “an introduction to designs, data analysis and model building”, Wiley & Sons, New York, USA, 1978。

The Comparative Study of Fatigue Crack Propagation Experiment and Computer Simulation on the Component Materials for the Crane Life Remained

Sangyeol Kim1, Hyungsub Bae1, Myeongkwan Park1, Seongsoo Kim2, Hanshik Chung2, Heekyu Choi3

1School of Mechanical of Engineering, Pusan National University, Busan, Korea; 2Department of Precision & Mechanical Engineer- ing and Eco-Friendly Heat & Cold Energy Mechanical Research Team, Gyeongsang National University, Gyeongnam, Korea; 3School of Nano & Advanced Materials Engineering, Changwon National University, Gyeongnam, Korea。

Received November 24th, 2010; revised December 13th, 2010; accepted January 10th, 2011。

ABSTRACT This study presents fatigue crack propagation experiments and the simulation used to estimate the life remaining in a crane that is currently in use at a port。 The fatigue crack propagation experiments were performed by an Instron 8516 fatigue testing machine and the simulation was performed using the AFGROW software。 The simulation results indi- cated that the critical size of the crack in the upper flange surface of the main jib was 107。4 mm and that it would take 818 000 cycles to reach that point。 If the main jib of the crane undertakes 28 800 cycles per annum then its remaining lifespan should be 28。4 years。

Keywords: Crane, Fatigue Crack Propagation, Computer Simulation, Crane Life Remained

1。 Introduction

The cracks in a crane installed in a port are propagated by the repeated operation of the crane over a long period of time。 A crane may fail, causing a serious accident, if a crack exceeds its critical size。 The analysis of fatigue crack propagation is the most important factor in the analysis of the stability and lifespan of the crane but it may require time and expense to investigate it experi-

propagation software。 The crane’s remaining lifespan can be deduced from the simulation results for the main jib [5]。

2。 Theoretical Background

Most of the current research on crack propagation uses the widely accepted Paris Equation [6]。

In this equation

mentally。  Computer  simulation  is  especially  useful for

studying the flow of granular assemblies or powders in

da  dN  C ΔK m

cases where it is difficult to obtain detailed results by direct experimentation [1-3]。 Hence, in order to be    effi-