A/SP Report Quantifies Mass Compounding Effect During Vehicle Design
Report Includes Mass Compounding Calculator for Download and Use

Vehicle design engineers intuitively know that an unplanned mass increase in a component during vehicle design has a ripple effect throughout the vehicle; other components need to be resized increasing vehicle mass even more. The phrase "mass begets mass" describes this phenomenon.

A more encouraging view of this behavior is considering a reduction in the mass of a component enabled by a new technology, resulting in a greater mass saving for the overall vehicle. These secondary mass changes can be considerable—estimated at an additional 0.7 to 1.8 times the initial mass change. 

This mass compounding behavior may be modeled using subsystem mass influence coefficients—the  incremental change in subsystem mass for a unit change in gross vehicle mass. Published data on influence coefficients is sparse, and that published are based on vehicles in the 1975–1981 model years.

This report, published by the American Iron and Steel Institute's Auto/Steel Partnership, defines and quantifies the mass compounding effect during vehicle design with current mass influence coefficients developed from mass data of 35 contemporary vehicles. Mass compounding considers that a mass increase in a component has a ripple effect throughout the vehicle; other components need to be resized increasing vehicle mass even more. A more encouraging view of this behavior is considering a reduction in a component mass resulting in a greater mass saving.

Also available for download with the report is a Mass Compounding Calculator, an Excel Spreadsheet that implements the findings of the mass compounding study into a tool for estimating initial vehicle mass based on conventional vehicle baselines and calculating the additional mass savings possible from an initial mass reduction of a vehicle system(s) or component(s).

You can download the report and the calculator at the Auto/Steel Partnership site.  After clicking the link, scroll on the page to Future Generation Passenger Compartment to locate the documents.