Search results

An energy-absorbing device is an important tool that is capable of increasing the survivability of passengers in vehicles. Generally, empty metallic tubes are used, and it is found that the energy absorption capability is lower than the energy obtained using composite materials. Therefore, this paper numerically presents the crushing performances of hybrid tubes under axial and oblique compressions.

Three important parameters are used such as fiber thicknesses, fiber orientations and oblique compression angles. Epoxy-reinforced fibers are wrapped around the steel tubes and it is then modeled numerically using the ANSYS finite element program. Belytscho – Tsay shell element is used to model the composites, while a bilinear kinematic hardening model is used to model the steel tube. A proper contact algorithm is implemented to prevent interpenetration among elements and surfaces.

A proper contact algorithm is implemented to prevent interpenetration among elements and surfaces. Hybrid tubes are quasi-statically crushed and force–displacement curves are extracted and analyzed.

It is found that the introduction of oblique compressions has induced bending moments and therefore decreases the energy absorption capability. Varying fiber orientations also insignificantly changed the crushing performances. However, wrapping carbon/epoxy composite that is capable of strengthening the tubes, is also subjected to oblique compression compared with the glass/epoxy composites.

This paper aims to develop a “line of sight” between improved military capability through supply network effectiveness to trust and shared values, and test the proposition that the effectiveness of the UK's military supply network (SN) will reflect the extent of the shared values within that network.

Using a three unit case study, the extent of the shared values is tested using a computer aided text analysis technique and an amended version of the Kuhn and McPartland Twenty Statements Test.

The research was unable to demonstrate alignment between higher levels of shared values and SN effectiveness. This may reflect the marked differences between commercial SNs which incorporate an assumption of near total elasticity of supply and aim at “on time in full” delivery, and their military counterparts which, not least for budgetary constraint reasons, do not have the same drivers of performance.

Further investigation should be undertaken to examine the generalisability of the research findings both within the UK and internationally.

The research underlines the caution that should be exercised when attempting to migrate commercial SN management thinking to a military environment.

Notwithstanding the vast sums expended on the provision of defence logistics, there is only very limited consideration of how best to achieve the appropriate balance between efficiency (low cost – especially in peacetime) and effectiveness (life saving – especially in war). This research offers some early insights using two novel techniques that represent valuable alternative means of understanding the impact of issues such as trust and shared values within SNs.

Continuous process improvement has been widely taught in business schools and has yielded real results and success in both for-profit and non-profit sectors. Though there have been many cases developed for use in business schools, few, if any, situate the topic in a military context. Further, expeditionary logistics presents managers with special problems of being removed from their supporting enterprise systems that process, track, and/or control of such logistical elements as purchase orders, inventory, distribution, receivables, and fulfillment. The authors present a case in a military setting that exposes students to the challenges of expeditionary logistics and takes them through the fundamentals of process analysis and process improvement.

The authors used a research methodology of a case study. Data were collected during field visits over the course of multiple interviews. Interviews were conducted with subject matter experts and active professionals serving in US Navy expeditionary logistics roles regarding processes and process performance.

This case can be applied to senior undergraduate or graduate-level courses in operations management, supply chain management, or logistics.

The theoretical bases adopted in this paper are supply chain management, information technology, operations management, and process improvement methodologies such as Six Sigma and Lean.

Managing product life cycle data is important for achieving design excellence, product continued operational performance, customer satisfaction and sustainment. As a result, it is important to develop a sustainment simulator to transform life cycle data into actionable design metrics. Currently, there is apparent lack of technologies and tools to synthesize product life time data. The purpose of this paper is to provide a description of how a product sustainment simulator was developed using fuzzy cognitive map (FCM). As a proof of concept, and to demonstrate the utility of the simulator, an implementation example utilizing product life time data as input was demonstrated.

The sustainment simulator was developed using visual basic. The simulation experiment was accomplished using a FCM. The Statistical Analytical Software tool was used to run structural equation model programs that provided the initial input into the FCM and the simulator. Product life data were used as input to the simulator.

There is an apparent lack of technologies and tools to synthesize product life time data. This constitutes an impediment to designing the next generation of sustainable products. Modern tools, technologies and techniques must be used if the goal of removing product design and sustainment disablers is to be achieved. Product sustainment can, therefore, be achieved using the simulator.

The sustainment simulator is a tool that demonstrates in a practical way how a product life time generated data can be transformed into actionable design parameters. This paper includes analysis of a sample generated using random numbers. The lack of actual data set is primarily due to reluctance of organizations to avail the public of actual product life time data. However, this paper provides a good demonstration of how product life time data can be transformed to ensure product sustainment.

The technique used in this research paper would be very useful to product designers, engineers and research and development teams in developing data manipulation tools to improve product operational and sustainable life cycle performance. Sustainment conscious organizations will, no doubt, benefit from a strong comparative and competitive advantage over rivals.

Utilizing the simulator to transform product life time data into actionable design metrics through the help of an efficient decision support tool like the FCM constitutes a step in supporting product life cycle management. The outcome of this paper alerts product designers on parameters which should be taken into account when designing a new generation of a given product(s).

This paper develops a methodology for identifying, classifying, and implementing a set of best practices that can increase the quality, reliability, and timeliness of industries that provide maintenance, repair, and overhaul (MRO) services on products. By cataloging and documenting these best “sustainment” practices, one can learn from others' attempts to maintain systems and avoid non‐value‐added processes. The authors identify the knowledge that exists at various research centers and MRO providers at US corporations – wherever the best practices may reside. The paper specifically focuses on the sustainment of US military systems, but it also draws analogies and conclusions for other global product and service providers.

This paper is motivated by the need to assess the risk profiles associated with the substantial number of items within military supply chains. The scale of supply chain management processes creates difficulties in both the complexity of the analysis and in performing risk assessments that are based on the manual (human analyst) assessment methods. Thus, analysts require methods that can be automated and that can incorporate on-going operational data on a regular basis.

The approach taken to address the identification of supply chain risk within an operational setting is based on aspects of multiobjective decision analysis (MODA). The approach constructs a risk and importance index for supply chain elements based on operational data. These indices are commensurate in value, leading to interpretable measures for decision-making.

Risk and importance indices were developed for the analysis of items within an example supply chain. Using the data on items, individual MODA models were formed and demonstrated using a prototype tool.

To better prepare risk mitigation strategies, analysts require the ability to identify potential sources of risk, especially in times of disruption such as natural disasters.

Rising operational costs and software sustainment concerns have driven the Air Force to move to newer technology to ensure that the Air Force Standard Base Supply System (SBSS) can continue to provide affordable and sustainable mission support in the years to come. This paper aims to summarize the successful software modernization effort the Air Force undertook to achieve that objective.

The paper describes the preliminary system updates that were required to isolate the SBSS software from all internal and external system and user interfaces in preparation for the subsequent successful code roll effort. Once the legacy SBSS component was fully isolated, the SBSS software modernization objective was achieved via a “code roll” conversion of the SBSS software from legacy COBOL to Java code, and movement of the integrated logistics system-supply application from a proprietary information technology (IT) platform to an open IT operating environment.

The SBSS system modernization yielded immediate and significant IT operational cost reductions and provided an important foundation for achieving Air Force logistics system consolidation and cloud computing objectives going forward.

The SBSS modernization experience should be useful in assisting similar data system software modernization efforts.