The continuously growing social and political pressure to provide sustainable products is forcing also the lightweight industry to rethink current development and manufacturing processes. While established development approaches in lightweight engineering mainly focus on technical and economical product requirements they usually do not consider sustainability criteria. To address these challenges, a new class within the lightweight disciplines is proposed—theNeutral Lightweight Engineering. Its basic goal is to integrate sustainability criteria in all decisions along the development chain of a lightweight component. The decision makers in lightweight engineering thereby have to consider the whole life cycle of a product system from material sourcing to end-of-life part management. To implement this idea, advanced development methods are necessary, using established and emerging materials as well as efficient production and end-of-life strategies. This concept article introduces the idea ofNeutral Lightweight Engineeringand exemplary highlights some of its aspects before the background of scientific literature.

The rapidly growing wind industry poses a fundamental problem for wind turbine blade (WTB) disposal in many areas of the world. WTBs are primarily manufactured from composites consisting of a thermoset matrix and reinforcing fibers. Currently, there are no economically viable recycling technologies available for such large-scale composite products. Thus, other treatment strategies for disposed WTBs have to be considered. This study explores the repurpose of WTBs as a promising alternative approach from a processual and technological point of view. For this purpose, the study is guided by the categorization into four different types of repurposed applications: high-loaded complete structure (T1), low-loaded complete structure (T2), high-loaded segmented structure (T3), and low-loaded segmented structure (T4). A three-dimensional CAD model of an Enercon-40/500 (E40) wind turbine blade is derived in a reverse engineering procedure to obtain knowledge about the actual geometry of the WTB. Based on the design, three ecosystems of product scenarios (S) with different manufacturing technologies involved are investigated: a climbing tower (S1), a playground (S2) and the combination of a photovoltaic (PV)-floating pontoon, and a lounger (S3). A screening life cycle assessment (LCA) is conducted to evaluate the three repurposed scenarios according to environmental aspects. It is shown that the repurpose of E40 WTB composite material can reduce the environmental impact and leads to significant resource savings in relation to a reference product of similar quality. A particularly high saving potential is identified for the substitution of emission-intensive materials in construction applications. Furthermore, it is found that transport processes are the primary contributor to the environmental impact of repurposed applications.

This paper investigates how environmental assessment methods can be systematically integrated into an industry-established engineering development process based on the VDI 2221 guideline, as applied in the development of aerospace components at Rolls-Royce Deutschland. Integration points for ex-ante assessment are identified, focusing on the applicability of Life Cycle Assessment (LCA), Screening-LCA, and CAD-integrated Life Cycle-Based Design Assessment (LCBDA). An adapted development process is derived and applied to the conceptual development of a novel lightweight front case structure for a business jet engine. The environmental performance of this design is compared to conventional titanium and magnesium-based alternatives. The case study illustrates how material selection and lightweighting decisions influence environmental impact, particularly in the use phase. The findings demonstrate the feasibility and limitations of integrating environmental assessment into high-technology aerospace development and offer guidance for balancing environmental and technical design criteria under industrial constraints.