Component Mass Study Statistical Benchmarking

Transcription

1 Component Mass Study Statistical Benchmarking Benoit Singher, A2Mac1 Automotive Benchmarking Russ Balzer, WorldAutoSteel Donald Malen, University of Michigan GDIS217

2 Statistical mass benchmarking Programs available for Europe, North America, China, Thailand, India and coming soon for south America A database of over 5 vehicles fully disassembled Over 11 parts reviewed per vehicle with data on mass, dimensions, materials, suppliers, coding, fasteners Average of 25, photos available per vehicle Over 4, parts stored and available for further review Additional 25 new cars in North America, 2 in Europe, 12 in China, 12 in India are dissembled every year 2

3 15 Components analyzed Components Analyzed Closures Front door Hood Hatchback Decklid Liftgate Chassis Lower control arm McP & SLA Wheels Front suspension Rear suspension Bumper beams Front & Rear Body systems Body structure IP beam 3 Seat frame

4 History of studies using A2Mac1 database Automotive Mass Benchmarking This report May, 21 January,

5 Tear down count by model year 214 study 2 vehicles This study 25 vehicles 8 21 study 1 vehicles Number of vehicles Analyze data in 5 year increments to detect trends Model year 5

6 Attributes of vehicles in this study Distribution approximately uniform by model year Destination markets primarily NA & Europe Asia Europe NA Other Heavily weighted to sedan and hatchbacks Primarily Front wheel drive 6

7 System Mass Structure Mass Structure Mass Objectives Determine mass statistics for Aluminum and Steel unadjusted for mass drivers Steel Alum Mean Std Dev Count Create scatter plots of component mass vs significant mass driver Determine mass-driver equation for component if Alum mass to allow objective comparison m STRUCT AREA 1. if Steel Area Identify efficient designs of each material and compare mass Identify material factor for each component M ALUM /M STEEL Nominal Efficient Designs Design Area 7 For selected subsystems, compare Aluminum-to-Steel mass reduction for Structure and for System Structure mass

8 Method 1 Define subsystem 2 Extract subsystem mass & mass driver data 3 Mass statistics Scatter plot analysis 4 Regression process 5 Best fit models Power m=b x b1 1 x b Propose mass drivers Linear m=b +b 1 x 1 +b 2 x 2 Extract data from website A2Mac1 Data quality control 6 Mass efficient designs 7 Identify utliers Parity plot 8 Compare mass efficient designs Sub system Mass Mass driver mass efficient designs Actual Mass low mass outliers Estimated Mass 8

9 Component Mass Study - Statistical Benchmarking Description of study and method Example: Body structure Key observations 9

10 Body Structure Mass kg Body Structure Mass kg Steel Model Year Mean Std Dev 56.5 Count 12 Body Structure: Raw data Mean Std Dev 66.7 Count 28 Aluminum and Steel/Alum Model Year Mean Std Dev 46.4 Count Mean 38.8 Std Dev 21.3 Count Mean Std Dev 63.8 Count 31 Alum Steel CFRP/Alum Steel/Alum Mean 32.8 Std Dev 34.8 Count 6

11 Body Structure: Definitions The body structure consists of the body-in-white with front sub-frame less doors including paint, sealer and mastic sound treatments. Vehicles with full frames have been excluded. Structure Mass drivers analyzed Gross Vehicle Mass Plan View Area 11 Material -Steel -Aluminum -Steel / Aluminum

12 Body Structure Mass kg Body Structure: Comparison with earlier data Body Structure Mass kg Body Structure Mass vs Plan View Area Area m Alum Steel Alum Steel CFRP/Alum Steel/Alum Body Structure Mass vs Gross vehicle mass GVM kg 12

13 Body Structure Mass kg Body Structure: Regression Models Mass-efficient designs were quantified by the number of standard errors, r, below the nominal. The criterion for choosing the number of standard errors below nominal, n, was at least three data samples were observed with mass equal to or less than that value Steel Body Structure Mass nominal efficient Nominal.652 Alum m STRUCT.448 GVM AREA.917 St.Al 1. Steel R 2 =.89, r=1.63 n STEEL =1.9 n ALUM =.924 n ST/AL = Efficient Area m GVM AREA m STRUCT r n.652 Alum.917 St.Al 1. Steel

14 Structure mass kg Structure mass kg Structure mass kg Current study 214 study 21 study Body Structure: Comparison of studies.652 Alum m STRUCT.448 GVM AREA.917 St.Al 1. Steel.656 Alum m STRUCT 1.59 GVM AREA.947 St.Al 1. Steel 1.2 FWD Alum m STRUCT GVM AREA 1. RWD 1. Steel 1.8 AWD Comparison of Efficient Designs R 2 =.89, r=1.63 n STEEL =1.9 n ALUM =.924 n ST/AL =.94 R 2 =.87, r=1.85 n STEEL =1.5 n ALUM =.875 R 2 =.83, r=1.94 n STEEL =1. n ALUM =.914 Typical Area used for graphs Study Alum Steel Study Alum Steel 5 4 Current Study Alum Steel Gross vehicle mass kg Gross vehicle mass kg Gross vehicle mass kg

15 Actual Mass kg Body Structure: Examples of mass efficient designs Alum Steel Steel/Alum Increasing mass efficiency Aluminum Body 214 Land Rover Mixed Aluminum/Steel Body 214 Cadillac CTS Expected Mass kg Steel Body 213 VW Golf VII 15

16 Component Mass Study - Statistical Benchmarking Description of study and method Examples Body structure Key observations 16

17 Body Structure Mass kg Key Observations There is a considerable range of mass for steel components of the same size and function. Thus, there is an opportunity in current production vehicles for mass reduction, even with the technology and materials already in use. 6 Body Structure Mass Possible opportunity for mass reduction using steel grades available now A=7.5 m 2 Area m 2 A=7.5 m 2 Variability in structure mass of similarly sized components

18 Key Observations When compared to an efficient steel design, the mass savings gap with aluminum significantly reduces. Mass ratio greater for efficient designs Mass Alum Mass Steel for efficient designs 18 Mass Alum Mass Steel

19 Key Observations Mass saving achieved in the structure due to material substitution is often not realized at the system level. Mass reduction from aluminum structure not fully carried over to system mass reduction 19

20 For More Information Benoit Singher A2Mac1 Automotive Benchmarking (1)