Search

Deformation of foliated rocks commonly leads to crenulation or micro-folding, with the development of cleavage domains and microlithons. We here consider the effect of mechanical anisotropy due to a crystallographic preferred orientation (CPO) that defines the foliation, for example by of alignment of micas. Mechanical anisotropy enhances shear localisation (Ran, et al., 2018; de Riese et al., 2019), resulting in low-strain domains (microlithons) and high-strain shear bands or cleavage domains. We investigate the crenulation patterns that result from moderate strain simple shear deformation, varying the initial orientation of the mechanical anisotropy relative to the shear plane. We use the Viscoplastic Full-Field Transform (VPFFT) crystal plasticity code coupled with the modelling platform ELLE (http://www.elle.ws; Llorens et al., 2017) to simulate the deformation of anisotropic single-phase material with an initial given CPO in dextral simple shear in low to medium strain. Deformation is assumed to be accommodated by glide along the basal, prismatic and pyramidal slip systems of a hexagonal model mineral. An approximately transverse anisotropy is achieved by assigning a small critical resolved shear stress to the basal plane. An initially point-maximum CPO at variable angles to the shear plane defines the initial straight foliation at different angles to the shear plane, limiting ourselves to orientations in which the foliation is in the stretching field. The resulting crenulation geometries strongly depend on the orientation of the foliation and we observe four types of localisation behaviour: (1) synthetic shear bands, (2) antithetic shear bands, (3) initial formation of antithetic shear bands and subsequent development of synthetic shear bands, and (4) distributed, approximately shear-margin parallel strain localisation, but no distinct shear bands. The numerical simulations not only show the evolving strain-rate field, but also the predicted finite strain patt

C' shear bands are common structures in ductile shear zones but their development is poorly understood. They occur in rocks with a high mechanical strength contrast so we used numerical models of viscoplastic deformation to study the effect of the proportion of weak phase and the phase strength contrast on C' shear band development. We employed simple shear to a finite strain of 18 in 900 steps and recorded the microstructure, stress and strain distribution at each step. We found that C' shear bands form in models with ¿5% weak phase when there is a moderate or high phase strength contrast, and they occur in all models with weak phase proportions ¿15%. Contrary to previous research, we find that C' shear bands form when layers of weak phase parallel to the shear zone boundary rotate forwards. This occurs due to mechanical instabilities that are a result of heterogeneous distributions of stress and strain rate. C' shear bands form on planes of low strain rate and stress, not in sites of maximum strain rate as has previously been suggested. C' shear bands are ephemeral and they either rotate backwards to the C plane once they are inactive or rotate into the field of shortening and thicken to form X- and triangle- shaped structures.

This research employed a case study strategy to examine the benefits of using synthetic environments to provide mission preparation for command and control teams prior to a large-scale, live warfighting exercise. During Pitch Black 08, we compared the performance of two Air Battle Management (ABM) teams: one team prepared by supporting normal flying operations, the other took part in a virtual mission preparation exercise named Black Skies 08. The synthetic environment provided in Black Skies 08 was designed to simulate Pitch Black 08 as closely as possible in terms of mission scenarios, order of battle, airspace, procedures, and tactics. The evaluation of the training provided in the virtual mission preparation was carried out using the four-level model: Reaction, Learning, Behavioural, and Results critera. The members that participated in Black Skies 08 reported that the virtual mission preparation compared favourably to both regular training and live exercises in terms of the capacity to provide training experiences critical to the ABM role. Over the course of the virtual mission preparation, the ABM team displayed a marked improvement in teamwork processes, motivational state, and across most mission essential tasks. During the subsequent live warfighting exercise, the teamwork processes and taskwork performance of this team were rated as better overall than those of the matched ABM team that did not take part in virtual mission preparation. The virtual mission preparation also demonstrated a broader organisational and operational value to the RAAF: it provided the White Force with the opportunity to identify deficiencies in, and mitigate risks associated with, the Pitch Black mission scenarios; and it allowed the ABM team to refine their Pitch Black plans and procedures, enabling them to more effectively utilise the valuable training opportunity presented by a large-scale, live warfighting exercise., Part one of two. See also ADA516761, Part Two: An Evaluation of Tools and Techniques, DSTO-TR-2305, AR-014-564. The original document contains color images.

Exercise Black Skies 2008 (EBS08) was a simulation exercise conducted in the weeks prior to the live air combat training exercise, Pitch Black 2008 (PB08). During EBS08, a Royal Australian Air Force (RAAF) air battle management (ABM) team conducted a series of vignettes designed to prepare them for their tactical command and control role in PB08. A broad goal of EBS08 was to provide an environment within which a number of new simulation tools and training techniques could be evaluated and developed for future implementation within the Royal Australian Air Force (RAAF). The tools and techniques evaluated were: the Air Defence Ground Environment Simulator (ADGESIM), Toteboard, Air Warfare Assessment and Review tool, After Action Review tools and the Team-Dimensional Training framework. These evaluations, which form the basis or this report, were informed by the observations of human factors scientists and interviews with the RAAF participants. Participants provided extensive feedback on each tool, highlighting shortcomings and providing valuable suggestions for improvement. This feedback will guide the further development of these tools for implementation in future research exercises and in RAAF training programs. Overall, the participants found EBS08 extremely valuable and were satisfied with the quality of training they received. The simulation tools and training techniques assisted in promoting the quality of this experience and prompted participants to consider methods by which the current RAAF approach to training could be improved., Part two of two. See also ADA516754, Part One: An Evaluation of Training Effectiveness, DSTO-RR-0344, AR-014-567. The original document contains color images.

Distributed simulation provides warfighters with training to enhance their team and inter-team skills with greater frequency and at lower cost than range training exercises. Distributed simulation training for small groups of warfighters such as a formation of four fighters working with an Air Battle Manager can be focused on specific skills such as beyond-visual range, dissimilar air combat tactics using constructive simulations as adversary forces. Training for command and control teams, however, requires interactions among blue force entities, particularly voice communication, that cannot be supported using only constructive simulations. One solution is to conduct large scale virtual training events such as VIRTUAL FLAG exercises. Another solution is to combine human-in-the-loop virtual simulators with white-force role-players who provide responsive verbal communications for constructive entities. Both of these approaches require participation from a significant number of warfighters or subject matter experts which increases training cost and decreases ability to focus training on command and control teams such as Air Battle Managers. To overcome these difficulties, Australian and US researchers conducted Exercise Pacific Link 2 in which an Air Battle Manager team in Melbourne, Australia was networked with a fourship of F-16 simulators and a constructive forces simulator in Mesa, Arizona. Using a novel approach to scenario design combined with an improved constructive entity generator, a small team of pilots and engineers provided five, fully interactive four-aircraft formations of F-16s which engaged multiple waves of adversary aircraft over a one-hour vulnerability period. Evaluations from the Air Battle Management team demonstrate significant training benefits from this approach. Data were presented on constructive forces improvements and results, system and scenario design together with feedback from exercise participants., Presented at the Interservice/Industry Training, Simulation and Education Conference (I/ITSEC) held in Orlando, FL on 26-29 Nov 2007. Published in the Proceedings of the Interservice/Industry Training, Simulation and Education Conference (I/ITSEC), Paper 7104, 2007.

In the military the use of teams to perform complex work functions is pervasive. Team performance is therefore critical, across a range of work contexts, for fulfilling operational requirements. To understand team performance, it is necessary to measure team performance. Valid and reliable measurement of the variables underlying effective team performance is fundamental to both team training and team training research, as it enables the determination of the strengths and weaknesses of teams, the design of targeted training programs, the provision of constructive feedback, and the evaluation of training effectiveness. This report presents, for the first time in a single resource, an overview of both the variables underlying effective team performance and the ways in which these variables have been operationalised and measured in the research literature.