Audi chooses fibreglass for lightweight springs
As part of its quest for ever-greater fuel efficiency, Audi is introducing glass fibre-reinforced polymer (GFRP) springs in its vehicles from the end of this year.
The springs are said to offer weight savings of 40% compared to steel ones. "The GFRP springs save weight at a crucial location in the chassis system," explained Dr Ulrich Hackenberg, member of the board of management for technical development at AUDI AG. "We are therefore making driving more precise and enhancing vibrational comfort."
The core of the springs consists of long glass fibres twisted together and impregnated with epoxy resin. A machine wraps additional fibres around this core – which is only a few millimetres in diameter – at alternating angles of plus and minus 45 degrees to the longitudinal axis.
These tension and compression plies mutually support one another to optimally absorb the stresses acting on the component. In the last production step, the blank is cured in an oven at temperatures of over 100°C.
The GFRP springs can be precisely tuned to their respective task. The material doesn't corrode even after stone chipping and is also impervious to chemicals such as wheel cleaners.
