Fracture failure analysis of baseplates in a fluidic amplifier made of WC-11Co cemented carbide
Journal Title: Frattura ed Integrità Strutturale - Year 2014, Vol 8, Issue 27
Abstract
A fluidic amplifier is a crucial automatic control component in a liquid jet hammer used to drill hard formations in the oil industry. This study aims to determine the true causes of the fracture failure of baseplates in a fluidic amplifier made of WC-11Co cemented carbide in a very short period of time. Computational fluid dynamics (CFD), theoretical estimation, and finite element analysis (FEA) were employed to analyze the effect of static and dynamic loads on the strength of the baseplates. Fractographic, metallographic, and processing defect analyses were also carried out. The FEA results showed that the static and dynamic loads caused stress concentrations at the actual fracture locations, and the effect of working loads on material strength was allowable and safe. Fracture surfaces exhibited typical characteristics of a brittle fracture. The metallographic analysis revealed that a specific amount of brittle eta-phase (η-phase) was present in the material. The microstructure of the processing cutting zone was inspected and the results revealed that some voids, pores, and microcracks were formed on the processing surface. The manufacturing and processing defects resulted in low stress fracture failure of the baseplates.
Authors and Affiliations
H. Liu, K. Yin, J. M. Peng, Q. L. Yin
Residual strength evaluation by DBEM for a cracked lap joint
The present work summarizes a numerical procedure aimed at the evaluation of the residual strength of a cracked lap joint, based on the competing failure mechanisms regulated by the R-curve analysis and plast...
Field Load Acquisition and variable amplitude fatigue testing on maxi-scooter motorcycles
Aim of the present work was the instrumentation of a maxi scooter for the field collection of service loads acting on the scooter main components such as frame, fork, handlebar, rear frame and suspension. Service...
Experimental and numerical study of cemented bone-implant interface behaviour
Although the total hip replacement (THR) is a long-proven method of surgical treatment of diseases and disorders of the human hip, the surgery brings some risk of long-term instability of the joint. The aim of the resear...
Response of porous SMA: a micromechanical study
Lately porous shape memory alloys (SMA) have attracted great interest as low weight materialscharacterized by high energy dissipation capability. In the present contribution a micromechanical study ofporous SMA is...
Effect of centrifugal load on crack path in thin-rimmed and webbed gears
Thin rimmed and webbed gears are used in particular applications to reduce systems weight. This kind of gears need an accurate and fail safe design. As a matter of fact, a possible failure, due to bending fatigue,...