Peterson, G. and Peterson, A., "Cost-Effectiveness of a Lightweight BIW Design for 2020-2025: An Assessment of a Midsize Crossover Utility Vehicle Body Structure," SAE Technical Paper 2013-01-0667, 2013, doi:10.4271/2013-01-0667.
This paper describes the methodology and analyses used to engineer and evaluate a 37% mass-reduced body structure relative to a baseline, steel body-in-white (BIW). This paper is based on two published Lotus studies including “An Assessment of Mass Reduction Opportunities for a 2017-2020 Model Year Vehicle Program” (2010 - Phase 1) and “Evaluating the Structure and Crashworthiness of a 2020 Model-Year, Mass-Reduced Crossover Vehicle Using FEA Modeling” (2012 - Phase 2). The links to these papers are included in the References section on page 12.The results of the 2010 paper, which projects a potential vehicle curb weight reduction of over 30% and a 38% reduction for non-powertrain systems, are summarized. An example demonstrating the total vehicle holistic approach is included. A summary of the methodology, which included a high level of component integration, parts reduction/elimination, reduced scrap and lower cost tooling, is discussed. A full vehicle mass and cost summary is reviewed; these results were the basis for the 2012 study.A lightweight, multi-material body CAD model matching the baseline vehicle geometry was then refined using strain energy density analyses to develop the body stiffness. The structural model was then iterated based on crash performance relative to federal standards, including front, side, rear and roof crush. The results, including acceleration levels and intrusion distances, are reviewed relative to federal requirements, acceptable industry practices and the baseline vehicle.A financial analysis, including piece costs, tooling costs and assembly costs, is also included as well as a review of a new BIW assembly plan capable of processing the multi-material, adhesively bonded structure.