摘要

There are various ways of determining the static in-plane shear properties of a fib re-rein forced composite. One of them is the standard three-rail shear test, as described in "ASTM D 4255/D 4255M The standard test method for in-plane shear properties of polymer matrix composite materials by the rail shear method". This setup, however, requires drilling holes through the specimen. In this study, a new design based on friction and geometrical gripping, without the need of drilling holes through the composite specimen is presented. Quasi-static tests have been performed to assess the symmetry of the setup and the occurrence of buckling. Then, fatigue tests were done to assess the behaviour of the grips under fatigue loading conditions, yielding excellent results; the specimen fails under shear loading conditions in the loaded area. The material used to validate this setup was a carbon fabric-reinforced polyphenylene sulphide. During fatigue, this material shows an increase in permanent deformation and a decrease in shear stiffness until a certain point in time, after which a drastic increase in deformation and temperature, higher than the softening temperature of the matrix occurs. Furthermore, the maximum value of the shear stress for fatigue with R = 0 has a large influence on the fatigue lifetime.

  • 出版日期2008-5