Comportamiento mecánico de materiales plásticos a fluencia (creep) en el diseño de producto. Caso de estudio: consola central de un automóvil

The strong evolution of automotive industry in the recent past years has accentuated the need of new methodologies in product development in order to ensure that the demand expectations from clients are fulfilled in the final product. The nowadays shorter requirements of developing periods and the increase of quality and reliability levels demanded, have encouraged engineering tools as the Finite Elements Method FEM, to lead the design quickly to intermediate well oriented to the final solution prototypes, in the different stages of the life cycle of these products.

In the assemblies of interior systems of vehicles, where a high participation of plastic products exists, it is very important to control all those phenomena related with that kind of viscoelastic materials that may affect the mechanical behaviour of the product following the requirement documentation specified from the client needs. A proper characterization is of actual interest nowadays.

Plastic materials display a low response under creep. Nowadays, in automotive inner systems industry, creep models are not used in numerical analysis, although they exist in libraries of many standards in market numerical codes. The main reason is lack of knowledge in the phenomenon and the difficulty of analyze the behaviour of large groups with assumable computational times.

In the following article a performed study about creep, using FEM, is presented, evaluating mathematical models that are now available and outlining on the feasibility in industry. The analysis has been performed using specimens, later the information obtained is used in real part and finally in a whole group of parts of the central console of a real vehicle.