Proceedings of the ASME 2013 International Mechanical Engineering Congress & Exposition IMECE2013 November 15-21, 2013, San Diego, California, USA IMECE2013-63520 SUSTAINABILITY-DRIVEN TOLERANCING AND DESIGN OPTIMIZATION OF AN AIRCRAFT ENGINE COMPONENT Steven Hoffenson * Product and Production Development Chalmers University of Technology Gothenburg, Sweden Email: stevenh@chalmers.se Anders Forslund Product and Production Development Chalmers University of Technology Gothenburg, Sweden Email: anders.forslund@chalmers.se Rikard S ¨ oderberg Product and Production Development Chalmers University of Technology Gothenburg, Sweden Email: rikard.soderberg@chalmers.se ABSTRACT Design for sustainability requires decision-makers to simul- taneously consider the economic, ecological, and social conse- quences of their products and production processes for a broad range of stakeholders. While some choices may mutually ben- efit the three sustainability categories, there are often tradeoffs where improving one objective comes at a cost to another. Pre- vious studies have shown that geometric tolerance decisions can affect all three sustainability criteria and create tradeoffs, par- ticularly when they are made in conjunction with other design decisions. This paper presents a framework for analyzing prod- uct design decisions through a multi-objective optimization ap- proach to sustainable design, tailored to the application of an aircraft engine turbine component. Models are constructed for production and maintenance costs, ecological impacts from man- ufacturing and use, and social impacts from neighborhood noise and delays caused by reliability-based maintenance events. Us- ing advanced computational simulation and optimization, trade- offs are shown and sustainable decision-making strategies are discussed. INTRODUCTION Sustainable design is the successful balance of all economic, ecological, and social consequences of the resulting product over its lifetime. In some cases, improvements to one sustainability objective require sacrifices to another. In practice, this trade- off often favors economic goals, which are the only hard re- * Address all correspondence to this author. quirement for corporate survival, but rising interest in ecological preservation and social consequences are pushing organizations to consider the other two aspects of sustainability. Companies that consider all three sustainability criteria benefit from higher customer perception and demand for their products, as well as a stronger position than their competitors in the event that govern- ments begin taxing these impacts. Design decisions from the conceptual phase through the de- tailed design phase can have competing effects on economic, ecological, and social objectives. Studies show that geomet- ric tolerances alone can exhibit a tradeoff among these objec- tives due to product variation, and more significant tradeoffs ex- ist when also including decisions such as materials and product geometries. This paper presents a framework for understand- ing these tradeoffs as they relate to product design, simultane- ously accounting for manufacturing costs, ecological impacts, and social sustainability. Using a multi-objective optimization approach, sets of optimal designs are found and compared to understand the relationships among the sustainability objectives and how corporate sustainability strategies may influence de- sign outcomes. As sustainability is particularly visible in the aerospace industry, this article demonstrates the approach using a case study representing an aircraft turbine component. When designing a turbine rear structure (TRS), a compo- nent on the tail-end of an aircraft engine, design decisions such as geometric dimensions and tolerances, material choice, and the number of vanes connecting the inner and outer hubs can in- fluence manufacturing costs, structural strength, engine weight, aerodynamic efficiency, and operating noise. Estimating these 1 Copyright c  2013 by ASME