Friction testing of thermoplastic composites
Friction phenomena play a major role in thermoplastic composite forming processes. In order to make use of the large potential these materials have, accurate CAE tools are needed that as a consequence incorporate temperature, pressure and velocity dependent friction behavior. To obtain a sound understanding of friction behavior a large number of friction measurement set-ups have been described in literature. A benchmark to compare different testing methods was proposed during the Esaform2010 conference. 
In this paper the material (Twintex PP) and testing conditions for the benchmark are briefly revisited and first testing results employing the in-house developed friction tester are presented. It is observed that the results reproduce very well at different conditions. Based on the Hersey number the Stribeck curve for the tested material combination is derived. It is concluded that a full state of hydrodynamic lubrication was reached with friction coefficients between 0.15 and 0.5. This opens up good perspectives for numerical modeling since all parameters are readily available in process simulations. Future comparisons within the context of the benchmark will assess the quantitative level of the identified coefficients of friction.
Characterising and Modelling Tool-ply Friction of Viscous Textile Composites (CD-rom)
The first part of the paper describes two experimental methods for measuring the tool-ply friction behaviour of impregnated thermoplastic textile composites. These include the so-called pull through test and tests conducted using a commercial rheometer using a custom designed platen. Results from the two techniques are compared and the relative advantages and disadvantages of the different test methods are discussed. Data produced over a range of temperatures, normal pressures and shear rates using the rheometer are employed to produce a master equation for the steady state friction. The method of shifting the data to produce this empirically determined equation is described. In the second part of the paper, a predictive meso-scale model is presented that incorporates parameters such as fabric architecture, tow geometry and matrix viscosity. The model is based on lubrication theory and can predict steady state friction. Predictions from the model are compared with experimental results.
A feasibility study of adolescent sex education: medical students as peer educators in Edinburgh schools
Objectives To determine the feasibility of medical students being involved in sex education in secondary schools, as lesson leaders in peer group discussions.