Showing papers by "Rhys Jones published in 2012"
TL;DR: In this article, a variant of the Hartman-Schijve equation was used to represent both modes I and II constant amplitude delamination growth in composites, and it was shown that the delamination rate can be related to (Δ√G−− Δ √Gth)α, where α is approximately 2.
110 citations
TL;DR: In this article, the Hartman and Schijve equation was used to estimate the small crack behavior based on long crack data for both long and small cracks, although a different value of ΔKth was required for small cracks compared to that required for long cracks.
86 citations
TL;DR: In this paper, a 3D nonlinear thermal stress analysis model has been used to calculate thermal stress of the rail wheel for all applications in the braking load spectrum and the residual life of railway wheel under service conditions has also been predicted.
28 citations
TL;DR: In this paper, a method for solving thermal fatigue crack growth in the rail wheel under stop braking spectrum is presented, where a finite element model of the wheel is used for all braking applications.
24 citations
TL;DR: In this paper, a fracture mechanics based approach for setting the inspection intervals associated with the growth of small naturally occurring defects is proposed, which has the potential to account for the discrepancy in the initial defect size.
Abstract: The deterioration of adhesive bonds as a result of exposure to aggressive service environments is a problem for both metallic and composite bonded joints in aircraft structures. In this context airworthiness issues arising from the in service growth of small naturally occurring defects in adhesively bonded repairs has led to the need to develop a fracture mechanics based approach for setting the inspection intervals associated with the growth of such naturally occurring defects. This involves issues associated with both durability and damage tolerance that are associated with such small defects because it is well known that, for metals, the use of long crack data can lead to erroneous non-conservative estimates. As such a means for assessing the issues related to such small naturally occurring defects is urgently needed. In this context the Boeing Wedge test, and its related variants, plays a central role in not only qualitatively assessing environmental performance but also in ranking surface treatments. However, this method has the problem that the initial defect introduced during wedge testing may not be representative of the small initial defects that can arise in service. Thus the relative ranking of various surface treatments obtained using wedge tests may be misleading. To this end, the paper presents a simple fracture mechanics based method that has the potential to account for the discrepancy in the initial defect size. This approach resembles crack growth laws developed to account for the growth of both long and short cracks in metals, environmentally enhanced crack growth in metals and delamination growth in composites.
13 citations
TL;DR: In this article, the authors present the results of a study into methods for estimating the residual lifetime of the rail S-shape plate rail wheel due to cyclic mechanical loads and thermal loads.
12 citations
TL;DR: In this paper, the effect of corrosion preventive compounds (CPCs) on the growth of cracks emanating from fastener holes in a typical (pressurised) fuselage lap joint was investigated.
8 citations
01 Jan 2012
TL;DR: In this article, the results of a series of experimental studies into the ability of SPD doublers to extend the fatigue life of thin aluminium structural components and the limit of viability (LOV) of fuselage lap joints are presented.
Abstract: This paper discusses repairs and modifications to thin load bearing aircraft structures using Supersonic Particle Deposition technology, a topic which is currently under consideration by both the Australian Naval Aircraft Systems Project Office (NASPO) and the RAAF Directorate General Technical Airworthiness (DGTA). Ensuring continued airworthiness is of paramount importance and it is essential that (aircraft) structural integrity be maintained after repairs have been installed. To this end the present paper summarises the results of a series of experimental studies into the ability of SPD doublers to extend the fatigue life of thin aluminium structural components and the limit of viability (LOV) of fuselage lap joints.
7 citations
01 Jan 2012
TL;DR: The results of the development of squats under alternating loads are described, to find squats growth path solution to a complex rail/wheel contact problem.
Abstract: This paper describes the results of the development of squats under alternating loads. An evolutionary program has been developed to simulate squats growth. The code is based on genetic algorithms and the whole field of evolutionary computation. Evolution strategies are derived from the biological process of evolution, to find squats growth path solution to a complex rail/wheel contact problem.
2 citations
03 Oct 2012
TL;DR: In this paper, the average block variant of the Generalised Frost-Dugdale law was used to predict the growth of small cracks in a USAF study into crack growth in D6acsteel specimens representative of the critical region of F-111 wing pivot fitting.
Abstract: Cracking in D6ac steel has played a key role in the development of thedamage tolerant design philosophy. Until recently it had been thought thatcracking in D6ac steel was well understood. However, Forth et. al. [1] haverecently reported that crack growth data obtained by NASA for D6ac steelrevealed that there was little R ratio dependence in the Paris Region and that therewas thus little, if any, crack closure. In this paper we reveal how the NASA dataconforms to the Generalised Frost-Dugdale crack growth law. We then show howthe average block variant of the Generalised Frost-Dugdale law can be used topredict the growth of small cracks in a USAF study into crack growth in D6acsteel specimens representative of the critical region of F-111 wing pivot fitting.
03 Oct 2012
TL;DR: In this article, the authors analyzed aseries of NASA and Boeing studies into cracking in Ti-6AL-4V to reveal a weakR ratio effect with little closure in Region II.
Abstract: There is an increasing use of titanium in primary aircraft structures withbulkheads in the F-22, Super Hornet, and the Joint Strike Fighter being made oftitanium. Until recently it was thought that cracking in titanium and high strengthaerospace steels was relatively well understood. However, this paper analyses aseries of NASA, and Boeing studies into cracking in Ti-6AL-4V to reveal a weakR ratio effect with little closure in Region II. We also see that, in each case, thedata conforms to the Generalised Frost-Dugdale crack growth law. This study alsoimplies that the mechanisms driving cracking in high strength aerospace steelsand Mil Annealed Ti-6Al-4V are similar.