Lightweight methodologies

Nair. S, et al. Understanding the practice of Safety Evidence Assessment A Qualitative Semi-Structured Interview Study. Technical report, Simula Research Laboratory (2014) Denney, E., Pai, G. A lightweight methodology for safety case assembly. In Qrtmeier, F., Lipaczewski, M. (eds.) SAFECOMP 2012. LNCS, vol.7612, pp. 1-12. Springer, Heidelberg (2012)... 

Despite its weaknesses (such as described in the 1975 collection of essays The Mythical Man Month [11]), the traditional software development life cycle (collect requirements, design, implement, test, deploy, maintain) has remained the standard framework for software development. However, in recent years it has become clear that the life cycle is not well suited to applications that are experimental in nature (i.e., where there is no precedent for the particular kind of application) or that exist in rapidly changing environments. This has led to the development of agile methodologies (also known as lightweight... 

Fiber-reinforced polymer structures are typically laid up by hand, consolidated (compressed together) with the polymer resin matrix material, and cured with heat and pressure. This method is capable of producing uniquely shaped, strong, and lightweight structural pieces. Fiber-reinforced polymers can also be used in mass-production methods thermoplastic materials can be employed to produce many relatively simple shapes that do not call for high strength. Variations on these methods, such as extrusion and pultrnsion, represent combinations of these methodologies. 

The next step we see in RTM is to introduce passive and active control which can account for part to part variability and reduce the scrap rate and make the process more reliable and attract manufacturers to consider lightweight composites as a serious alternative to stamped aluminum parts. There are control algorithms available which in unison with flow simulations (offline in which one anticipates the differences and creates a decision tree based on the disturbance that can be identified with sensors, and online simulations which try to correct the flow during injection) can be integrated in an automated environment which will make RTM competitive for high volume production. This methodology has been demonstrated in a laboratory environment and hopefully will be adopted by some industries to reap the benefits. Until then RTM will serve as prime candidate for low volume specific design components. 

This process is cost competitive with generic production methodologies like the vacuum bag technique. It requires lower investment and non-recurring costs are lower compared to conventional autoclaves. Utilization of flexible tools and lightweight composite tools are additional advantages. Further advantages and limitations of the Quickstep process are listed in Table 14.6. 

---