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By S. Ando

The fatigue crack growth behavior of magnesium single crystal has been investigated, CT (compact tension) type specimens with different notch orientations were prepared. In the case of notch plane and direction are (1-210) and [10-10], fatigue crack propagates parallel to notch, From TEM observation, it is found that pyramial slips occures at the crack tip. When notch is normal to basal plane, a fatigue crack propagates [0001] and parallel to basal plane depending on stress intensity factor range, In the case of notch parallel to basal plane, a fatigue crack propagates through straight route with some {10-12} twin, Fatigue crack growth rate, da/dN of A- and B- specimen is lower than F-specimen with crack parallel to basal plane.

Jan 1, 2004

By Dennis A. Fenton

This paper presents some techniques and data required to design large ball mills. The advent of larger size mills leads to consideration of the gearless drive as a practical solution to utilize large horsepowwers. The particular shell structure under consideration is subjected to thermal as well as magnetic loads. The magnitude of the inertia, magnetic and shell temperature characteristics have a very significant effect on the design and performance of the hydrodynamic pivoted shoe bearing. Particularly since these bearings have lower frictional resistance properties than hydrostatic trunnion tee rings. The structure of the mill is designed for long life. Parameters involved with the fatigue life of the structure are discussed together with some of the more important aspects of the design.

Jan 1, 1975

By D. A. Aranda-Regino, C. Gómez-de-la-Garza, J. Ramírez-Cuellar, L. A. Leduc-Lezama

The Pickling Line Tandem Cold Mill (PLTCM) at Ternium’s Pesqueria plant with a 5 stands, 6 high configuration started in 2013. At the time of the start up the work roll specification and grinding practices were stablished following a low risk policy to be able to sustain any start-up associated accident. Once a stable operation has been achieved both these policies are being modified to improve productivity and reduce costs. The specified hardness of the rolls has been increased and efforts are being made to optimize the grinding according to the rolling campaign length and materials. The fatigue damage in work rolls, after rolling and its removal by grinding was followed by hardness measurements made at the end of the rolling campaign and after grinding. Softening of the rolls after rolling was found mainly in final stands to be related to the averaged stress experienced during the campaign, the original roll hardness was recovered after grinding. Hardness evolution was also followed after each grinding step finding that the total amount of grinding could be reduced. The grinding practice was modified accordingly for the first stands and the yield of work rolls in them has improved.

Oct 1, 2019

By W. J. Theron

The purpose of the paper is to give an introduction to the concept of fatigue and its causes in the mining industry. By knowing the fundamental role it plays, together with its dynamics, can positively contribute to a mine?s safety management system. The difference between physical and psychological fatigue will be addressed with a possible range of causes that could trigger fatigue. There are two main sources of fatigue: firstly, work-related fatigue which is associated with activities at the workplace; and secondly non-work-related fatigue. The shared responsibility between the employer and employee is also discussed as it involves factors that occur both in and outside the workplace. Employers have the responsibility to manage fatigue through using a risk management approach. Employees have the responsibility to ensure they get enough sleep, take sufficient and regular nutrition, are healthy and physically fit and come to work fresh and alert. The impact of the implementation of a fatigue management plan and procedures has the potential to eliminate employee fatigue or its causes, reduce the likelihood of fatigue occurring in the workplace, and counteract the effects of fatigue when it occurs. Factors considered when implementing a fatigue management system include: extended hours of work, shift work, time of day and work design. Fatigue is one of the major role players (either causal or contributory) when it comes to causes of fatalities in the mining industry. Our main challenge in identifying whether fatigue played a role is the fact that it cannot be tested in post-mortems like drug or alcohol abuse. It is an aspect worth understanding and getting an organization sensitive to managing it properly to benefit both organizational as well as employee needs. Keywords Signs of fatigue: Causes of fatigue, circadian rhythms, the fatigue equation, fatigue management, fatigue affecting safety, fatigue fighting tips, lifestyle suggestions.

Jan 1, 2011

By A. Becker, R. Tait, S. L. George, A. Carlisle

Surface treatments like laser shock peening (LSP) induce residual stresses penetrating up to 1 mm deep, surpassing traditional methods, thus significantly increasing the potential impact on materials prevalent in the automotive and aerospace sectors. Through extensive fatigue testing and fractography investigations, it was determined that LSP resulted in a fatigue life increase of over five times for aluminium alloy AA7075-T6 and titanium Ti-6Al-4V. Increased fatigue life was also noted in AISI316 stainless steel, which showed increases in fatigue life of 1.7x. While fatigue life in all cases improved, the efficacy of LSP was shown to be material dependent.

Jul 23, 2025

By M. Matema

Paper written on project work carried out in partial fulfilment of BSc (Eng.) Metallurgy and Materials Engineering Small and large welded aluminium specimens were tested in fatigue and the results compared with design curves for aluminium in specification BS8118. Metallurgical tests were also performed on the specimens in order to correlate microscopic and macroscopic phenomena. The small-scale fatigue test results were in reasonable agreement with results in BS8118, whereas the large-scale fatigue tests showed that BS8118 is conservative.

Jan 1, 2005

By Scales PJ

Fatigue is the primary cause of failure of structural and mechanical components subject to dynamic loading. Recognition of this basic fact and the development of appropriate techniques and details are important in the design and repair of off highway trucks (OHTs). The frames and appendages of OHTs and other mobile plant used in the Pilbara are subject to tough operating conditions. Any fatigue-prone details quickly show up and become a maintenance liability of considerable concern. Much of this equipment is approaching the limit of its fatigue life and maintenance managers face decisions on whether to repair or replace. Even new equipment often contains some poor details which suffer distress soon after commissioning. In those cases a repair is required which will reinstate the detail to its original intended design life. Repair details must be practical and cost effective. They must also be tailored to the capability and expertise available in the field or in local manufacturers' establishments. This is particularly important where original equipment was manufactured overseas and long delivery times are involved. Lessons are drawn from components which have failed, using the evidence constructively, to provide an upgraded part or an improved substitute. With the experience now available it is relatively easy to extrapolate to cover new problem areas. This paper describes specialised techniques of mechanical fastening and detailing for low fatigue susceptibility, built up over many years of experience with OHTs and other mining plant and equipment in the Pilbara.

Jan 1, 1982

By T Dawson, B Haskins

Fatigue is it the newest buzz word or is fatigue a real phenomenon that is creating safety and organisational risk for you? There is no debate that fatigue is natural, and it affects us all, just like gravity; however, there has been much debate on the severity of its impact in the workplace. For many years the impact was not measurable, hidden out of sight and, quite frankly, written off as the infamous ‘operator error’. Over the last several years, advancements in technology have provided safety and health professionals, sleep scientists, fatigue experts and organisations with the ability to monitor and detect fatigue events in real time, as well as predict and monitor increased risk for fatigue events. Caterpillar Safety Services has assembled an extensive and exceptional set of technologies that will provide the best methods and data to measure the impact of fatigue. This paper will discuss fatigue in the workplace and review the technologies and data sets available, which will allow the reader to determine whether this risk is real or rubbish.CITATION:Haskins, B and Dawson, T, 2017. Fatigue risk in your operations – real or rubbish? It actually depends , in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 137–142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By P. C. Schutte

There have been several high-profile accidents in the South African mining industry where fatigue was identified as either causal or contributory. The risk of fatigue is inherent in any work-time arrangement involving shift work and work that is physically or mentally demanding, repetitive, or requires high vigilance. The management of fatigue is not simply a matter of correct shift scheduling. Amore comprehensive approach is needed. In order to be successful, a fatigue management programme should address the unique needs of the operation in which it will be implemented and should be integrated into normal operations. Fatigue management is a shared responsibility between the organization and its employees, and all stakeholders should participate in order to provide the safest and healthiest working environment possible.

Jan 1, 2010

By Luana De Lucca de Costa

A diversidade de aplicações dos produtos fabricados pelo processo de forjamento é atribuído a importante relação obtida entre a qualidade dos produtos e os custos de produção, entretanto, o custo do ferramental neste processo é expressivamente dispendioso. Estudos que envolvem a fabricação e manutenção das matrizes, em particular, a investigação das maneiras que gerem aumento do desempenho e da vida útil são de relevância acadêmica e fabril. Este trabalho explana os as particularidades que envolvem o projeto de matrizes para forjamento a quente em matriz fechada, tais como, ângulos de saída, linhas de partição, pré-formas, canais de rebarba, entre outros. O objetivo do estudo é reunir e esclarecer conceitos a fim de evitar erros de projeto e tornar o ferramental menos oneroso.

Aug 16, 2017

By Enrico Tosolini

O controle da massa linear dos arames CA60 vem sendo tratado com máxima prioridade, devido ao constante esforço da indústria nacional de reduzir os custos e melhorar a eficiência de produção. O trabalho é um estudo teórico dos fatores físicos que influenciam na variação da massa linear. Para desenvolver a análise, o problema foi simplificado para reconduzi-lo a um problema linear de fácil análise e com parâmetros intuitivos para fácil aplicação dos conceitos nos problemas diários da produção.

Aug 16, 2017

By Ahmed Yehia, M. A. Abdel-Khalek, J. D. Miller, M. Fadel

Recently, research efforts have been made to lower the magnesium content of phosphate rock concentrate to be a suitable feed for phosphoric acid production and other related industries. Among these efforts is the bioprocessing technique. However, this study is devoted to study of using an enzyme, extracted from coffee waste, as a surface modifier during the fatty acid flotation of calcareous phosphate rock. A mixture of oleic acid and kerosene was used as collector. Factors, which affect the enzyme activity such as enzyme dosage, solution pH, temperature and conditioning time, were studied. Under the appropriate conditions, a concentrate product containing less than 0.60% MgO was achieved from the Abu Tartur feed (1.80% MgO) with a P2O5 recovery of more than 94%.

Jan 1, 2002

By M Eggers, H Baxter

This paper discusses the geotechnical condition of bedding shears and small- and large-scale faults and shears in Archean banded iron formation (BIF) bedrock, based on observations of core and televiewer images. Information that can be collected includes the orientation of defects, infill thickness, strength and material type, defect shape and surface roughness.The spacing and continuity of bedding shears may be critical to slope design where performance is structurally controlled with bedding dipping out of a wall. The intensity of development of the bedding shear is a useful indicator of the amount of shearing a bedding surface has been subjected to. This can allow for engineering judgement to be used in adopting peak or residual shear strengths along defect surfaces when developing the design.The spacing and continuity of bedding shears may also contribute to the blockiness and degradation of a rock mass where the structural orientation is otherwise favourable. Additionally the condition, thickness and strength of infill of major fault structures can affect slope design and performance, depending on orientation.Comparison of the condition of structures observed in core with the corresponding in situ televiewer image has been made to assess what characteristics are most accurately captured by each technique and whether the additional information gathered from using the televiewer technique is justified by the cost. The question of whether the data collected by a televiewer is sufficient to ultimately replace the need for core is considered.CITATION:Baxter, H and Eggers, M, 2013. Fault and shear characterisation in archean banded iron formation bedrock - a comparison between core and televiewer data collection techniques, in Proceedings Iron Ore 2013 , pp 47-56 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By M. H. ElMaghraby

This paper describes the development and validation of a strategy for vibration-based online detection of faults in a particular class of machinery commonly found in industry. This machinery is defined by two basic characteristics that preclude it from the application of standard online condition monitoring approaches. The first characteristic is that the machine is in a constant state of transient operation, thus making it difficult to differentiate between changes in transducer measurements that are due to variable duty and those that are due to machine malfunction or fault. The second characteristic is the fact that the machinery involves multiple sub systems that are subject to identical and simultaneous loading, operating environments and duty cycles. An example of such machinery is a system of multiple hydraulic pumps driving a common load. The monitoring strategy presented here employs an anomaly detection scheme together with methods of signal processing and feature extraction that exploit the parallel duty arrangements of this equipment. Preliminary data is collected from a pair or motor-gearbox assemblies used in a material haulage system in the mining industry. Testing and validation was performed on a mechatronic test bench with both healthy and faulted components. Experiments were carried out to investigate how various configurations of the system were able to detect different types of faults. The results indicate that this approach is effective and merits further investigation.

May 1, 2013

By S-L. Jämsä-Jounela

Fault diagnosis systems have attracted growing interest in a number of engineering fields. The number of applications has increased and successful results have been widely reported. The fault diagnosis system presented in this paper is integrated, and it monitors the states of the process and performs fault detection and diagnosis on the process equipment. The monitoring of process states is carried out by means of Kohonen Self-Organising Maps that is a powerful tool in visualisation and analysis of high dimensional data in engineering applications. This paper presents the results of SOM analysis carried out on the Outokumpu flash smelting process. The subsystems analyzed in more detail are the condition of the concentrate burner, the condition of the gas line on the basis of the pressure distribution in the process and the cooling water circulation of the waste heat boiler, and the condition of the furnace and furnace equipment on the basis of the temperature distribution in the furnace and gas line. Keywords: Fault diagnosis, Process monitoring, Kohonen Self-Organising Maps, flash smelting

Jan 1, 2001

By Sullivan T. D, Lohe E. M

Geological structure is one of the main controls on ground conditions within mining. It has a significant impact on the mining conditions and productivity of coal mines within the Sydney - Bowen Basin. The three main types of faults common to this region, normal, reverse and strike-slip systems, each present distinct challenges to mining. These systems effect a wide range of geotechnical and mining conditions within the mines. These include coal quality, strata stability, goat and caving behaviour, productivity and maintenance schedules of mining equipment, mine design and mine-site stress fields. A better understanding of the regional, local and mine-scale structural setting, timing relationships of structural events and the mechanisms of fault formation will greatly aid industry's push for greater productivity and competitiveness.

Jan 1, 1991

By Burns K. L

Keyboard patterns of hundreds of minor faults with vertical displacements of 3 mm to 2 m occur within the Greta coal seam and cause serious mining problems in collieries. Many of the faults are concentrated in linear zones termed swarms. One swarm is 600 m wide and more than 800 m long and others are of comparable size.The minor faults between the swarms are normal and are relatively widely spaced and show dip-slip movements, but the faults within a swarm are clustered and show strike-slip and oblique-slip movements. Fault swarms ofthis size and frequency have not previously been described from the Sydney Basin or on a comparable scale elsewhere but appear to be a widespread phenomenon in Australian coalfields. The faults are assigned to classes onthe basis of orientation which are then assigned to sequential phases I to IV on the basis of offsetting relations between representatives of each class. Phase I faults are minor thrusts. Phase IT, Ill, and IV faults are concentratedin the swarms and show sinistral strike-slip and normal dip-slip movements. The interference of slickenlines indicates that multiple movements have occurred within a single phase; their order is (i) strike slip (ii) dip slip and (iii) oblique slip. All faults truncate and post-date both cleat and sedimentary "stone" dykes.Phase I minor thrusts trend at a high angle to the Hunter Thrust and are considered to predate the Late Permian movements on the Hunter Thrust. Phase II and III minor faults are younger and may be any age between the latePermian and Tertiary.

Jan 1, 1978

By Harold Hopkins

THE Wright-Hargreaves mine is one of a group of seven mines long active in the Kirkland Lake district, Ontario. Detailed geological reports and maps covering the area have been published by the Ontario Department of Mines (1,3)t. Though all these mines work several productive veins there is one vein which is common to all and is known as the North Vein of the camp?not that it is the most northerly vein mined, but it is the more northerly of the two major veins of the camp. At the Wright-Hargreaves mine there are in all ten important producing veins, and most of them have a N.60°-65°E. strike and in general a steep southerly dip. It is a common belief that most of these veins lie along faults but it will be shown that whilst this is true of some of them it is not true of all, and also that a vein may lie in a fault along part of its course and elsewhere fill a fracture in line with the fault, this being a consequence of rotational movements that took place during faulting. The paper describes the history of faulting at this mine in particular, makes observations on the principal pre-ore fault, and describes the method used in solving the movements on the post-ore faults. Other details of geology are not discussed except to mention here that our main veins lie almost entirely in the syenite porphyry stock except on lower levels close to the east boundary of the property, where the North vein leaves the porphyry to enter the greywacke.

Jan 1, 1940

By C Buchanan

For a long time there has been a known relationship between the northern Heavy Mineral (HM) deposits of the Murray Basin to the extensive north east trending ridges in the area. These ridges have been a targeting tool for exploration and have uncovered some significant discoveries, some of which have turned into mining projects. Bemax’s Ginkgo and Snapper deposits are good examples of how the faulting helped create an economic deposit but also result in significant planning issues in the exploitation of these deposits. Material balance, induration and pyrite issues have been made easier to manage through good geological understanding of the deposits.

Aug 22, 2011

By Vicki Tschirhart, Bill Morris, McMaster University

A new method for mapping faults within basement rocks underlying the Thelon Formation and glacial overburden was developed and tested in the Aberdeen Sub-basin. This method utilizes newly acquired aeromagnetic data, the Blakely algorithm for defining magnetic source edges, a calculated dip-direction map, a digital elevation model (DEM) derived from the Canadian Digital Elevation Database, and the positions of identified, inferred and newly mapped faults that are within and adjacent to this sub-basin. Combining these data revealed three age groups of faults. One group is seen only on the DEM; these faults are young brittle structures that have no effect on the sub-Thelon basement unconformity, and are not visible on the dip direction map. A second group is evident on the dip direction map but not the DEM; these faults are old basement structures that did not propagate upward through the Thelon Formation. The third group is expressed on both the DEM and dip direction map; these faults are also old structures that propagated upward during and/or after deposition of the Thelon Formation. The latter group of faults may be of greatest interest for uranium exploration, with reactivation increasing their potential to serve as conduits to transport uranium-rich fluids and focus deposition at or near the unconformity surface. This methodology has promise for comprehensive mapping of basin faults and tracking the tectonic development of the whole Thelon Basin through time.

Jan 1, 2013