Making Automobiles Lighter

A primary concern of auto manufacturers

Prof. Prashant P. Date

Department of Mechanical Engineering

IIT Bombay, Powai, Mumbai 400 076

RESEARCH FOCUS

• REDUCTION IN THE WEIGHT

Primarily

OF SHEET METAL COMPONENTS

Strategies of weight reduction

Present• Thickness reduction

• Use of Light Weight material

• Use of Tailor welded blanks

• Enhance Stiffness/Weight ratio

Future•Hollow structural parts

•Hydroformed parts

Thickness reduction

• Use High strength materials for

- side door impact beams

- clutch pedal

- brake pedal

In place of Low carbon steel

Thickness reduction

Part Low carbon steel

High Strength Steel

Side-door impact beams

( Shape factor ) 1.38 1.42

Clutch & brake pedal

(Thickness )

5 mm 4 mm

Light Weight material• Al-Li - High strength to weight ratio • Lower E compared to steel

- Formability of Al-Li alloy sheets at room

temperature

- Optimisation of heat treatment of Al-Li alloy sheets

Problems :

Cost & Weldability of Al-Li alloys

Al-Li alloy fender

Steel fender

Tailor Welded Blanks

• Deformation behaviour and weld line movement

of tailor-welded blanks of Aluminium and steel

• Effect of various parameters like thickness ratio,

rolling direction & width

• Study of Laser welding process for Aluminium

and steel

• Final aim is to design a weld contour to avoid

stressing the weld during forming.

Stiffness/Weight ratio by design• Weight reduction maintaining stiffness and dent

resistance

- Studies on the stiffness of formed sheet

metal parts

without external stiffeners using Finite

element analysis

- Extruded ribbed panel will be analyzed for

stiffness characteristics

Part quality by process design

THANK YOU

FOR YOUR ATTENTION