ORCID Profile
0000-0002-7885-5901
Current Organisation
Deakin University
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Publisher: IOP Publishing
Date: 09-2017
Publisher: Elsevier BV
Date: 04-2009
Publisher: IEEE
Date: 04-2019
Publisher: Elsevier BV
Date: 04-2012
Publisher: Elsevier BV
Date: 12-2022
Publisher: Elsevier BV
Date: 12-2019
Publisher: MDPI AG
Date: 02-07-2022
DOI: 10.3390/APP12136724
Abstract: Acoustic Emission (AE) is a promising technique for measuring tool wear online and in real time. In this work, scratch tests were conducted to better understand the “pre-wear” AE response based on loading conditions that were not sufficient to generate galling. The scratch tests used the same type of indenter against two different sheet materials: aluminum and steel. The results showed that AE parameters such as the mean frequency, Centroid frequency and Shannon entropy outperformed other frequency domain techniques by discriminating between the two sheet materials in scratch tests. From the literature, the frequency region of interest was expected to be sub 300 kHz. However, in this study, activity below this threshold was found to be noise, whereas distinct frequencies were found at much higher frequencies than expected. These results are compared against single grit “SG” tests of both mild steel- and nickel-based superalloys to allow comparison of the two test methods and materials used. This comparison showed that the SG tests excited the acoustic emission in ways in which the scratch tests did not. Another factor when using acoustic emissions to monitor sheet metal forming is the differences obtained in energy–frequency mapping, where many report the galling phenomena between a certain litude and frequency range. Such results are specific to the setup and the materials/geometries used. Further work presented here compares different scratch tests where energy–frequency mapping is different for different materials/geometries.
Publisher: Springer Science and Business Media LLC
Date: 16-04-2018
Publisher: IOP Publishing
Date: 21-09-2018
Publisher: Trans Tech Publications, Ltd.
Date: 12-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.421.750
Abstract: This paper discusses our recent research on wear at the die radius in sheet metal st ing. According to wear theory, contact pressure and sliding distance are the two dominant factors in determining sliding wear. We applied the finite element analysis to accurately quantify the contact pressure and sliding distance at the die radius in sheet metal st ing. The results were then applied to analyze sliding wear at the die radius. We found that a typical two-peak steady-state contact pressure response exists during a channel forming process. The steady-state contact pressure response was preceded by an initial transient response, which produced extremely large and localized contact pressures. We proposed a method to numerically quantify the sliding distance, which was applied to examine the contact sliding distance at the die radius. Correlating the contact pressure and sliding distance, a new insight into the wear/galling that occurs at the die radius in sheet metal st ing was gained. The results show that the region close to zero degrees on the die radius is likely to experience the most wear, with the identified transient stage contributing to a large proportion of the total wear.
Publisher: Elsevier BV
Date: 10-2019
Publisher: Elsevier BV
Date: 02-2019
Publisher: Elsevier BV
Date: 02-2016
Publisher: IOP Publishing
Date: 09-2017
Publisher: Elsevier BV
Date: 10-2020
Publisher: MDPI AG
Date: 07-07-2023
DOI: 10.3390/LUBRICANTS11070288
Abstract: Aluminum is a very commonly used material at present, and roughly half of the produced aluminum products undergo forming during manufacturing. Galling is a severe form of wear that occurs during sheet metal forming operations and is a common failure mode of materials in sliding contact however, the causes and mechanisms of galling are poorly understood. In this work, sliding wear experiments were conducted to produce galling wear between a tool steel ball bearing and aluminum alloy Al5083, to study the relationship between the coefficient of friction, the lump growth on the tool and the scratch morphology. Whilst the characteristic friction regimes were observed, the characteristic damage (grooves running parallel to the scratch direction) was not observed. Instead, when galling was developed on the indenter, the scratch surface morphology displayed a series of peaks and grooves perpendicular to the scratch direction. It is likely that the difference in scratch morphology observed once galling was initiated is due to the lower hardness and reduced work hardening behavior of the Al5083 alloy, compared to the high strength steels previously examined in sheet metal forming applications. The evolution of the scratch morphology has been characterized in a novel way by investigating the distribution of the longitudinal cross-section profile height along the scratch length in relation to the three-stage friction regime observed. This showed that, as the galling wear progressed, the longitudinal cross-section profile height distribution shifts towards negative values, with a corresponding shift in the distribution of material transferred to the tool shifting to the positive. This indicates that, as the amount of material adhered to the indenter increased, the depth of the grooves on the scratch surface perpendicular to the sliding direction also increased.
Publisher: AIP
Date: 2005
DOI: 10.1063/1.2011220
Publisher: Elsevier BV
Date: 05-2010
Publisher: IOP Publishing
Date: 11-2019
DOI: 10.1088/1757-899X/651/1/012085
Abstract: Tool wear and galling are of significant concern in the automotive st ing industry, due to the increase in use of higher strength sheet steels in automotive structures and reduced lubrication during st ing production. There are many methods explored in the literature and applied in industry to combat wear in st ing, including new die materials and coatings, alternative lubrication systems and better predictive models. However, smart condition monitoring will continue to be relevant in conjunction with these methods because it can provide further opportunities for production quality and cost improvements, despite the advancements of these other methods. This paper explores the use of multiple sensors and multiple signal processing techniques, aimed at developing a smart multi-sensor method to monitor galling wear. The three main sensors and corresponding signal processing techniques examined are: (i) measurement of punch force signatures analyzed via Principal Component Analysis (PCA) (ii) acoustic emissions signals measured via wideband sensors and examined using time and frequency domain features (iii) measurement of audio signals in the audible frequency range analyzed via blind signal separation techniques. For all techniques, a semi-industrial st ing test was used to provide realistic production-type conditions, albeit with accelerated wear rates. The relationship between the key outputs from the three sensor/analysis methods were directly compared to a new quantitative measure of galling wear severity. Based on these results, it was observed that a multi-sensor approach for wear condition monitoring provides an opportunity for the development of a smart monitoring tool that can actively track the progression of wear.
Publisher: Elsevier BV
Date: 11-2017
Publisher: MDPI AG
Date: 26-12-2020
DOI: 10.3390/MET11010038
Abstract: This study investigates the effect of grain size and composition on the material properties and forming limits of commercially supplied stainless steel foil for bipolar plate manufacture via tensile, stretch forming and micro-st ing trials. It is shown that in commercially supplied stainless steel the grain size can vary significantly and that ‘size effects’ can be influenced by prior steel processing and composition effects. While the forming limits in micro-st ing appear to be directly linked to the plane strain forming limits of the in idual stainless steel alloys, there was a clear effect of the tensile anisotropy. In contrast to previous studies, forming severity and the likelihood of material failure did not increase with a decreasing channel profile radius. This was related to inaccuracies of the forming tool profile shape.
Publisher: IOP Publishing
Date: 08-2016
Publisher: Aleksandras Stulginskis University
Date: 26-11-2015
DOI: 10.15544/BALTTRIB.2015.23
Abstract: The ‘wear mode diagram’ has been commonly used to classify the deformation regime of the soft work-piece during scratching, into three modes: ploughing, wedge formation and cutting. The scratch test is used to evaluate wear modes and material removal associated with wear. There are different damage models in the literature used for the description of material behaviour after damage initiation under different loading conditions. However, there has been little analysis to compare damage models during scratch test conditions. The first aim of this work is first to use a finite element modelling package (Abaqus/Explicit) to build a 3D model to capture deformation modes during scratching with indenters with different attack angles. Three different damage models are incorporated into the model and patterns of damage initiation and propagation are compared with experimental results from the literature. This work highlights the role of the damage model in accurately capturing wear modes and material removal during two body sliding interactions.
Publisher: SAE International
Date: 10-03-2015
DOI: 10.4271/2015-01-0062
Publisher: Elsevier BV
Date: 08-2014
Publisher: MDPI AG
Date: 02-03-2020
DOI: 10.3390/LUBRICANTS8030025
Abstract: In the sheet metal st ing process, during sliding contact between the tool and sheet, it is expected that severe events such as tool wear or fracture on the sheet generate acoustic emission (AE) burst waveforms. Attempts have been made in the literature to correlate the AE burst waveform with the wear mechanisms. However, there is a need for additional studies to understand the frequency characteristics of the AE burst waveform due to the severity and progression of the galling wear. This paper will determine the AE frequency characteristics that can be used to monitor galling wear, independent of the experimental process examined. The AE burst waveforms generated during the st ing and scratch tests are analysed in this paper to understand the change in the AE frequency characteristics with the galling severity. These AE burst waveforms were investigated using the Hilbert Huang Transform (HHT) time-frequency technique, band power, and mean-frequency. Subsequently, these AE frequency features are correlated with the wear behaviour observed via high-resolution profilometer images of the st ed parts and scratch surfaces. Initially, the HHT technique is applied to the AE burst waveform to understand the influence of wear severity in the power distribution over the wide AE frequency range. Later, the AE bandpower feature is used to quantitatively analyse the power in each frequency interval during the unworn and worn tool conditions. Finally, the mean-frequency of AE signal is identified to be able to determine the onset of galling wear. The new knowledge defined in this paper is the AE frequency features and wear measurement feature that can be used to indicate the onset of galling wear, irrespective of the processes examined.
Publisher: IOP Publishing
Date: 07-2018
Publisher: Elsevier BV
Date: 2012
Publisher: Trans Tech Publications, Ltd.
Date: 02-2019
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.794.285
Abstract: St ing tools are prone to an adhesive wear mode called galling. Adhesive wear on st ing tools can degrade the product quality and can affect the mass production. Even a small improvement in the maintenance process is beneficial for the st ing industry. Therefore, this study will focus on understanding and detecting the initiation of tool wear at the microscopic level in sheet metal st ing using acoustic emission sensors. St ing tests were performed using a semi-industrial st ing process, which can perform cl ing, piercing, st ing and trimming in a single cycle. The st ing test was performed using a high strength low alloy sheet steel and D2 tool steel for dry and lubricated conditions. The acoustic emission signal was recorded for each st ed part until severe wear on the dies was observed. These acoustic emission signals were later analyzed using time and frequency domain features. The time domain features such as peak, RMS, kurtosis and skewness could identify significant changes in the acoustic emission signal only when the severe wear was observed on the st ed parts for both dry and lubricated conditions. However, this study has identified that a frequency feature – known as mean-frequency estimate – could identify early stages of wear initiation at the microscopic level. Evidence of this early stage of wear on the part surfaces was not clearly visible to the naked eye, and could only be clearly observed via surface measurement instruments such as an optical profilometer. The sidewalls of the st ed parts corresponding to the initial change in AE mean-frequency trend were qualitatively correlated with 3D profilometer scans of the st ed parts, to show that AE mean-frequency can indicate the initial minor scratches on the sidewalls of the st ed parts due to the galling wear on the die radii surfaces. The results from this study can be used to develop a methodology to determine the very early stages of st ing tool wear, providing a strong basis for condition monitoring in the st ing industry.
Publisher: Elsevier BV
Date: 03-2013
Publisher: Elsevier BV
Date: 11-2008
Publisher: Elsevier BV
Date: 02-2017
Publisher: IEEE
Date: 06-2015
Publisher: Elsevier BV
Date: 07-2008
Publisher: IOP Publishing
Date: 09-2017
Publisher: Elsevier BV
Date: 11-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2017
Publisher: Elsevier BV
Date: 05-2016
Start Date: 2012
End Date: 2014
Funder: Australian Research Council
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