Material Values

The aim of the project is to develop an analytical model for temperature dependent material characteristics for short glass fiber reinforced thermoplastic under quasistatic loading.

Injection molding is widely used in modern lightweight construction due to a cost effective process and a high degree of manufacturability of complex structures. These structures are usually subjected to varying environmental and loading conditions such as elevated temperature and moisture. Hence, material characteristics taking consideration of temperature and moisture variation are required to design such components. Therefore, this project aims to develop non-linear analytical models which describe mechanical behavior of short glass fiber reinforced thermoplastic subjected to quasi-static loading under different temperatures. Mechanical behavior of thermoplastic material is highly sensitive to the glass transition temperature (below and above the glass transition temperature).

Similarly consideration of local fiber distribution and fiber length is also necessary in order to develop a methodology that can predict realistic proof of strength and life time of the component. This can be done by micro-modelling of test specimen with the help of 3D X-ray microscopy and  computer tomography. This micro-mechanical model can further be calibrated in FE-programs. With the help of this analytical model, the FE-program can calculate stress strain behavior considering 5 variables, i.e. fiber orientation, fiber length, fiber content, temperature and humidity. Such material models will ease the creation of a broad data base for material selection and design of polymer components.

• FVA Forschungsvereinigung Antriebstechnik e.V.