Advanced cost models for application in composite aero-engine components

Thakur, Nikhil (2019) Advanced cost models for application in composite aero-engine components. Post-Doctoral thesis, Birmingham City University.

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Abstract

Composites have been used all over the world when it comes to developing advanced light weight and highly efficient components. Companies like Boeing and Airbus have successfully used more than 50% composites by weight in their aircraft’s structural and non-structural parts, which has been found to increase efficiency, cut down weight by 30% and absorbed vibrations. This triggered a need to develop new and advanced engines that are both light in weight and efficient and can support these aircrafts. Hence, to cope with this new engineering requirement, companies like Rolls-Royce and General Electric are developing advanced engines using composite materials. The use of composites in aero-engines has brought forth certain challenges. One of the main challenge is to predict cost of the composite part very early in the decision making phase so as to improve design efficiency. The current methods/techniques of Cost Estimation (CE) have been designed taking a product or a manufacturing process as the basis and hence, show drawbacks, which include, (i) lack of knowledge regarding composite technology, (ii) platform dependent architecture, (iii) complex in its structure and implementation, (iv) knowledge less flexible and (v) not easy to maintain. Most of the drawbacks that the current methods/techniques have may be overcome by using Knowledge-based Engineering (KBE) techniques, whose benefits can be directly applied to the composite CE problem. However, to increase the flexibility and applicability of KBE along with an easy to use system, a more logical method is needed. It has also been seen and understood that the percentage cost share of carbon footprint in the overall cost of a product is of the order of < 20%. Thus, the inclusion of carbon footprint knowledge in terms of cost in the overall product life-cycle is very important and will increase the current capability of CE.

This work is the presentation of application of a mathematical set theory-based logical knowledge management system, which utilises the KBE’s principles for knowledge creation and integrates the same to the mixed CE approach. The basis for the knowledge creation is a novel way of using generic composite life-cycle which includes carbon footprint knowledge in terms of its cost impact from all the phases of the life-cycle. This way, a more logical and manageable system is created which can handle composite material based complexity and generate an advanced capability in cost estimation of an aero-engine component. The research is conducted in a systematic step-by step fashion in 3 parts. The first part covers literature review in the fields of composite technology knowledge, KBE, CE and carbon footprint. The second part covers the formulation of a logical set theory-based cost estimation methodology along with development of an advanced CE tool. The final part covers validation of the methodology and the tool on four aero-engine based component case studies along with an industry expert validation. From this research, the results revealed that the methodology developed is, (i) very good at handling complex information, (ii) reliable in estimating cost, (iii) platform independent, (iv) logical in knowledge management for composites and (v) easy to maintain and model. Further, the cost estimates generated are under a variance of less than 15%, which is an industry allowed limit. It has been seen that the developed advanced system increases the current cost capability and can also predict carbon footprint as a cost impact, which is a further advancement in the current system. Overall, it can be said that utilising the developed method, an advanced system can be created which is capable of, generating reliable cost estimates for composite aero-engine components, adds to the existing knowledge base and increases the existing capability in cost, proving to be more efficient and effective.

Item Type: Thesis (Post-Doctoral)
Date: 29 April 2019
Uncontrolled Keywords: Composite cost estimation, knowledge based cost estimation, logical cost estimation, advanced cost estimation techniques, carbon footprint and life cycle, costing of carbon footprint.
Subjects: H100 General Engineering
Divisions: REF UoA Output Collections > Doctoral Theses Collection
Depositing User: Doris Riou
Date Deposited: 18 Jun 2020 14:55
Last Modified: 18 Jun 2020 14:55
URI: http://www.open-access.bcu.ac.uk/id/eprint/9371

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