High strain rate tensile properties of rapidly cured woven carbon fibre composites

Tensile tests at high speeds corresponding to automotive crash events were conducted to understand the dynamic properties of rapidly cured woven carbon fiber composites. The High Strain Rate (HSR) experiments were conducted on a servo-hydraulic machine at constant velocities up to a maximum of 25 m/s (82 ft/s). Results from HSR tests were compared with the static results to determine the rate sensitivity of the composite. A high speed camera was used to capture the failure at HSR. The tensile properties of rapidly cured laminate were compared to oven cured laminate to justify its productivity while maintaining the desired properties. The methodology used to achieve constant velocity during HSR tests is discussed in detail. The specimen geometry was specially designed to suit the test rig and to achieve high speeds during tests. All the specimens failed with linear elasticity until sudden brittle fracture. The Scanning Electron Microscopy (SEM) images of the fracture zone were used to identify the failure modes observed at static and high strain rates.

Carbon nexus: a strategic overview and research highlights

Carbon Nexus (www.carbonnexus.com.au) is a globally significant research facility at Deakin University focused on the manufacture and use of carbon fibre. Carbon Nexus represents a partnership between Deakin University and the Victorian Centre for Advanced Materials Manufacturing (VCAMM) and houses two production lines capable of manufacturing industrially relevant quantities of aerospace grade carbon fibre. The facility enables scientists to conduct research into the chemical, mechanical and nano-scale characteristics of new carbon fibre materials produced on site. There is a strong focus on evaluating these new carbon fibre products in composite materials, particularly composites cured using out-of-autoclave techniques. This paper will present an overview of the vision for Carbon Nexus as well as the technical capabilities of both the laboratory scale single tow line and the larger pilot line capable of producing up to 50 tons of carbon fibre per year. Both lines are fully operational and able to convert a range of polymer precursors into carbon fibre. They are representative of world's best practice for carbon fibre manufacturing methods and well suited to conducting energy efficiency studies. Highlights from recent research projects will focus on the effect of the surface treatment and sizing of carbon fibre on fibre-matrix adhesion in composite materials. In addition to this, results from studies of the effect of varying processing parameters on the structure and properties of oxidised polyacrylonitrile and carbon fibre will also be presented.

Managing the requirements engineering process

Process management is a crucial issue in developing information or computer systems. Theories of software development process management suggest that the process should be supported and managed based on what the process really is. However, our learning from an action research study reveals that the requirements engineering (RE) process differs significantly from that which the current literature tends to describe. The process is not a systematic, smooth and incremental evolution of the requirements model, but involves occasional simplification and restructuring of the requirements model. This revised understanding of the RE process suggests a new challenge to both the academic and industrial communities, demanding new process management approaches. In this paper, we present our understanding of the RE process and its implications for process management.

Managing the requirements engineering process

Process management is a crucial issue in developing information or computer systems. Theories of software development process management suggest that the process should be supported and managed based on what the process really is. However, our learning from an action research study reveals that the requirements engineering (RE) process differs significantly from what the current literature tends to describe. The process is not a systematic, smooth and incremental evolution of the requirements model, but involves occasional simplification and restructuring of the requirements model. This revised understanding of the RE process suggests a new challenge to both the academic and industrial communities, demanding new process management approaches. In this paper, we present our understanding of the RE process and its implications for process management.

Understanding requirements engineering process: a challenge for practice and education

Reviews of the state of the professional practice in Requirements Engineering (RE) stress that the RE process is both complex and hard to describe, and suggest there is a significant difference between competent and "approved" practice. "Approved" practice is reflected by (in all likelihood, in fact, has its genesis in) RE education, so that the knowledge and skills taught to students do not match the knowledge and skills required and applied by competent practitioners.

A new understanding of the RE process has emerged from our recent study. RE is revealed as inherently creative, involving cycles of building and major reconstruction of the models developed, significantly different from the systematic and smoothly incremental process generally described in the literature. The process is better characterised as highly creative, opportunistic and insight driven. This mismatch between approved and actual practice provides a challenge to RE education - RE requires insight and creativity as well as technical knowledge. Traditional learning models applied to RE focus, however, on notation and prescribed processes acquired through repetition. We argue that traditional learning models fail to support the learning required for RE and propose both a new model based on cognitive flexibility and a framework for RE education to support this model.

Using protocol analysis to explore the creative requirements engineering process

Protocol analysis is an empirical method applied by researchers in cognitive psychology and behavioural analysis. Protocol analysis can be used to collect, document and analyse thought processes by an individual problem solver. In general, research subjects are asked to think aloud when performing a given task. Their verbal reports are transcribed and represent a sequence of their thoughts and cognitive activities. These verbal reports are analysed to identify relevant segments of cognitive behaviours by the research subjects. The analysis results may be cross-examined (or validated through retrospective interviews with the research subjects). This paper offers a critical analysis of this research method, its approaches to data collection and analysis, strengths and limitations, and discusses its use in information systems research. The aim is to explore the use of protocol analysis in studying the creative requirements engineering process.

Requirements engineering during global software development : some impediments to the requirements engineering process : a case study

Requirements engineering is not straightforward for any software development team. Developing software when team members are located in widely distributed geographic locations poses many challenges for developers, particularly during the requirements engineering phase. This paper reports on a case study concerning a large software development project that was completed in just seven months between users located in the UK and software developers from an international software house based in New Zealand. The case indicates that while “true” global requirements engineering may be desirable in achieving economy of resources, a “hybrid” structure of requirements engineering processes is more realistic so that lasting relationships with clients may be formed, and requirements engineering activities achieved. The main impediment to the process of requirements engineering during global software development, as recounted by the team members in this case, is communication. Communication issues may be further described in terms of four categories: distribution of the clients and the development team, distribution of the development team, cultural differences between the clients and the development team and cultural differences among the development team.

Critical success factors for the requirements engineering process, with reference to quality management of information systems development

Preliminary research into the critical factors associated with software development/implementation identified three dimensions for successful implementation based on alignment of the requirements engineering process with business needs, change management process and quality of the implementation process. Research results demonstrate the link between the conceptual model for process quality and the process management attributes determined during the research.