Development in Fatigue Design in Automotive Industry using new Materials

Abstract

The aim of extensive weight reduction in car design leads on the one hand to the use of lighter materials. But — on the other hand it leads to the increased exploitation of traditional materials. — This trend can be detected in body and trim features, steering systems, in running gear and drive components. When using alternative materials it should be borne in mind, that alongside the often many-sided aspects of function and reliability, economy frequently has a decisive influence. Fig. 1 compares the weight of cars in the past with future trends. By far the greatest part of vehicle’s weight in 1984, left hand side, consists of steel and cast iron, followed by plastics and aluminium. The bar graph on the right hand side shows the estimated shifts in each material’s percentage of the total weight. The proportion of steel, which was 60 % in 1984, will decrease to app. 45 % by the year 2000. The proportion of cast iron, on the other hand, will hardly change. A growth of between 5 and 8 % in the amount of plastics used can be expected. It will also be possible to achieve considerable weigth reductions in running gear and drive components by development of fibre compound materials. The same applies to the increased use of aluminium, the proportion of which will rise from app. 3 % in 1984 to app. 10 % in the year 2000.