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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 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

Fault detection and identification are major challenges in process engineering and manufacturing and the key component of abnormal event management systems. Timely detection, diagnosis and rectification of abnormal or faulty process conditions can lead to savings of billions of dollars in equipment damage and lost productivity, not to mention the prevention of injury and loss of human life associated with industrial accidents. A major contributing factor to current losses in industry is the reliance on human operators to interpret high-frequency samples from hundreds or thousands of variables simultaneously. As a result, the automation of fault detection and diagnosis is seen as crucial to the successful implementation of abnormal event management, the need for which is becoming all the more urgent given the increased complexity associated with modem industrial plants. In this paper, a methodology for process monitoring that uses support vector methods to extract nonlinear features from data is discussed and applied in the diagnostic monitoring of an industrial liquid-liquid extraction column.

Jan 1, 2005

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 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 Gerrit V. R. Goodman, Fred N. Kissell

The issue of miner safety in case of an underground mine fire has been extensively examined by both government and industry. These efforts have intensified in recent years following a number of fatal fires at underground coal mines. As a result, there is an increasing interest in the reliability of coal mine escapeways during a mine fire. This paper discusses the use of fault tree analysis for evaluating escapeway reliability. A fault tree is developed using standard logic formulations. It is later evaluated using commercially available software. The computer model uses Boolean reduction to obtain the minimal cut sets and minimal path sets of the tree. A brief analysis is also conducted to determine the occurrence probability of the TOP event. This study shows that fault tree analysis is a viable means of analyzing escapeway reliability. The cut and path sets reveal those event sequences leading to fatalities. Such information is useful in safety training and accident prevention. The probability of the TOP event shows the frequency of occurrence for fatalities in an underground mine fire. The usefulness of this value, however, is limited by the accuracy of the data for the initiating events. For mining events, the data is difficult to estimate precisely.

Jan 1, 1989

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 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

By N. I. Fisher, J. Shepherd

Abstract-Statistical studies have been carried out on structural geological data collected across a large zone of roof failure 600 m (1968 ft) wide and at least 800 m (2642 ft) long in the Greta coal seam at Aberdare East Colliery. Two swarms of hundreds 2 of minor, normal faults with throws commonly between 3 and 300 mm in the room and pillar workings are broadly coincident with roof failure. The faults have been classified into dip slip and oblique and strike slip types. Roof conditions have been classified into good; troublesome with subclasses scaly, heavy, gutter falls and wide, flat-roofed falls; and severely failed with subclasses very heavy roof, gutter falls and dome falls. Troublesome conditions are defined as those in which the height of the fall is less than or equal to 0.3 m, and severely failed conditions as those in which the fall height is greater than 0.3 m. Comparison of faults, roof conditions and mining rate on a shift basis indicates that faults and roof failure are much more important than machine breakdowns in reducing mining rate. The effect of faults on roof conditions has been quantified using a concept called the "zone of influence, " a rectangular area around a fault in which the fault has potentially deleterious effects. The spatial comparison of fault "zones of influence" with areas of roof failure using Spearman's rank correlation coefficient shows that, while normal dip slip faults do not appear to be associated with roof failure, oblique slip and strike slip faults appear to be associated with roof classed as severely failed. The "zone of influence" of an oblique slip fault may extend up to 3 m on each side of it in the headings and up to 1.14 m in the cut-throughs. The fault "zone of influence" has geomechanical implications for the design of mine openings and possibly represents the maximum length of a cantilevered roof beam likely to fail during mining, owing to a fault. Roof conditions could possibly be predicted in blocks of virgin coal if the type of fault could be identified in oriented drill cores.

Jan 9, 1978

By N. I. Fisher, J. Shepherd

Statistical studies have been carried out on structural geological data collected across a large zone of roof failure 600 m (1968 ft) wide and at least 800 m (2642 ft) long in the Greta coal seam at Aberdare East Colliery. Two swarms of hundreds of minor, normal faults with throws commonly between 3 and 300 mm in the room and pillar workings are broadly coincident with roof failure. The faults have been classified into dip slip and oblique and strike slip types. Roof conditions have been classified into good; troublesome with subclasses scaly, heavy, gutter falls and wide, flat-roofed falls; and severely failed with subclasses very heavy roof, gutter falls and dome falls. Troublesome conditions are defined as those in which the height of the fall is less than or equal to 0.3 m, and severely failed conditions as those in which the fall height is greater than 0.3 m. Comparison of faults, roof condition and mining rate on a shift basis indicates that faults and roof failure are much more important than machine breakdowns in reducing mining rate. The effect of faults on roof conditions has been quantified using a concept called the "zone of influence," a rectangular area around a fault in which the fault has potentially deleterious effects. The spatial comparison of fault "zones of influence" with areas of roof failure wing Spearman's rank correlation coefficient shows that, while normal dip slip faults do not appear to be associated with roof failure, oblique slip and strike slip faults appear to be associated with roof classed as severely failed. The "zone of influence" of an oblique slip fault may extend up to 3 m on each side of it in the headings and up to 1.14 m in the cut-throughs. The fault "zone of influence" has geomechanical implications for the design of mine openings and Possibly represents the maximum length of a cantilevered roof beam likely to fail during mining, owing to a fault. Roof conditions could Possibly be predicted in blocks of &gin coal if the type of fault could be identified in oriented drill cores.

Jan 1, 1979

By JESSE L. MAURY

DEVELOPMENT of new gold mines in Canada since the price of that metal was increased in 1932 and 1933 has been of interest and importance to many of us. The day-by-day story has given an impression of aggressive effort and enough good luck so that the spirit of enterprise has been encouraged. It is the purpose of this article to report the results of a statistical appraisal which give emphatic numerical confirmation to this impression, together with certain side lights on the costs of development and equipment of new mines. The data presented have been taken from all readily available published sources up to the close of 1938 and are representative of that year. A. B. Bower did a large part .of the spadework and Weston Thomas offered many helpful suggestions.

Jan 1, 1939

Data recently released indicate substantial improvement in mineral industry performance for 1984. Business plans to increase plant and equipment spending in 1984 by 14.8 percent, according to a recent survey conducted by the Commerce Department's Bureau of Economic Analysis (table 1). In contrast, capital spending by all industries declined 4.8 percent in 1983 and 2.3 percent in 1982. The latest estimate of planned expenditures for 1984 is $2.2 billion higher than the comparable estimate based on the survey conducted in late January and February 1984.1/ [ ] Of particular significance to the U.S. mineral industries are the 15.5-percent increase in capital spending planned by manufacturing in 1984 and the planned 18.6-percent increase in spending by durable goods manufacturing, where the largest increases are planned in the transportation equipment (26.4 percent) and electrical machinery sectors (23.5 percent). Capital expenditures in manufacturing declined in both 1982 and 1983.

Jan 1, 1984

By Sastry Putcha, Vamshi Vemula, Aneesh Goly, Kumar Allady

Current dynamic testing practice to obtain pile total capacity will not yield optimum capacity due to the strain incompatibility between the side and tip resistances during driving. Superposition of end of initial drive- static tip capacity and the peak static skin capacity during beginning of restrike and adding them is the preferred method. The FDOT method determines independent pile static tip and skin capacities in real time analyzing appropriate blows from the embedded tip and top data of the Embedded Data Collectors (EDC). This data is collected through a wireless radio transmitter, receiver, and laptop software. The approach utilizes EDC tip and top data and nonlinear single degree of freedom system to satisfy force and energy equilibrium with a global genetic inversion analysis. Top impacted energy equals at pile tip as sum of Static, Damping and Inertial energy providing independent tip resistance. With EDC sensors as boundary conditions, pile is divided into desired segments and using global inversion techniques one dimensional equation is solved for independent skin friction for every blow. EDC data compared close static load test results. The EDC - FDOT method has enabled cost effective 100% testing of driven piles cost effective. INTRODUCTION Historical documentation has shown that not only driven piles have a long history of usage but also continues to advance unceasingly till today. Historians placed the first pile driving using timber piles in the 4th century BC. While modern pile driving systematically started around nineteenth century, the credit for conceiving the idea of the applicability of wave equation to driven piles goes to David Victor Isaccs of Australia. His 1931publication “Concrete Pile Driving Formulae” provides the basis for modern pile driving using stress wave theory. He felt that the dynamic formulae then in use lacked the capability of detecting integrity and hence developed stress wave theory. This work was further developed starting in 1938 by W.H. Glanville and colleagues of British Building Research Board as they developed the first solution to the wave equation. But these early efforts have really taken off only with the advent of computers. E.A.L. Smith (1960) published ‘Pile Driving Analysis with the Wave Equation’ and provided first numerical solution to the wave equation. Within few years, the FHWA funded research and in due course this effort ushered the era of externally instrumented pile driving.

Jan 1, 2018

This paper describes a simple finite element (FE) modelling approach which leads to the computation of seismic energy release rate (ERR) and strain energy storage rate (ESR) which result from mining. The concept of critical strain energy is introduced as a means to help evaluate the strainburst potential in mine structures. A new, energy-based, burst potential index (BPI) is proposed. The use of ERR, ESR and BPI is demonstrated by a cut-and-fill stope case study. The merits of using such energy parameters in the interpretation and analysis of strainburst phenomena are discussed. While the study gives promising results, site-specific back analyses would be required to first calibrate the model and fit it with the local mine conditions, before it can be adopted as a routine design tool.

Jan 1, 1999

By Daniel Wild, Tobias Scheffer, Marvin Laugwitz, Martin Jochum

Leveling is a standard process in the rolling mill to eliminate flatness deviations. The process layout is based on models and the leveling result depends on the accuracy of the material parameters in these models. Even small deviations from the correct assumptions can have a major effect on the final flatness. Thus, after leveling the products may look optically flat, but subsequent to a final cutting process springback occurs due to residual stresses. The objective of this work is to analyze the influence of material parameters and gravity on the flatness after leveling. To evaluate the sensitivity of the process, an FE parameter study is exerted that reveals the influence of fluctuations in material properties in the case that the leveling setup is fixed. Gravity is neglected to not conceal flatness deviations. Examples of this study are rerun in a further step under consideration of gravity to also analyze its influence on the resulting flatness and residual stresses. Finally, to analyze the consequence of the residual stresses, all information of the plate from the previous step are transferred while gravity is suppressed to prompt springback. This study revealed that slight deviations of the material properties can lead to uneven plates in simulations where gravity is not considered. If gravity is taken into account, the unevenness is concealed and the plate seems flat. A springback simulation of the same plate shows that strong residual stresses are still present and would lead to unevenness if e.g. the plate were cut.

Oct 1, 2019