Failure Analysis on the Fracture Shaft of a Centrifugal Pump Used for Diesel Engine Cooling System

Abstract

Shaft failures often occur, even in the shafts of centrifugal pumps. This study aims to determine the cause of shaft fracture through experimental and numerical study. The fracture surface was observed using Scanning Electron Microscopy (SEM) to identify the initial crack. The chemical composition test results show that the material used was in accordance with the AISI 420 standard, which is necessary to make Finite Element Analysis (FEA) modelling. Shear stress, strain and stress intensity factors were analysed around the fillet using FEA. The results show that the value of maximum stress intensity factor, KI, occurs in the multilevel shaft fillets that experienced initial cracks due to torsional loads. The shear stress value, obtained from the FEA, was higher than the shear stress value of the material. The KI value, also derived from the FEA, was higher than the KICvalue of the material.