Coupled material selection and shape optimization for efficient sustainable switchgear design

The design of mechanical switchgear components has traditionally focused on cost, safety, and reliability. While these remain priorities, sustainability is becoming increasingly important. However, sophisticated sustainability analysis requires precise specifications, making early-stage implementation challenging. This paper introduces a novel methodology that couples a classical product design process with sustainability assessment. It links systematic material selection with shape optimization, allowing evaluation of sustainability and cost criteria for functional parts rather than generalized material indices according to Ashby. Costs and emissions of materials and manufacturing processes are considered based on material usage. The impact of recycled content is also examined. The methodology is extendable to include more structural design calculations and diverse evaluation criteria, enabling flexible adaptation to specific design requirements. The approach is evaluated using two components of a load break switch drive: a spring-loaded lever attached to a shaft and the housing. Results are compared to common assessments based on material indices. The interaction between the shaft and housing is considered in a joint optimization, revealing phenomena such as higher contact stresses from smaller, high-strength shafts leading to thicker housings. This integrated methodology supports well-founded decision-making in early product development stages.