Abstract
The mechanical in-plane shear testing method for unidirectional CFRP panels has not yet been authorized internationally because of its difficulty in obtaining the uniform shear stress field. A revised picture-frame fixture was proposed to obtain the essential in-plane shear properties along fibers in the previous paper, but the specimen configuration included curved corners which exhibit stress concentration. In the present paper, an attempt was offered to simplify the specimen configuration in order to obtain more uniform shear stress distribution than as seen in the previous specimens which were used in the picture frame fixture. Furthermore, another proposal was offered where the fiber direction was changed perpendicularly in rail shear methods. The experiments on unidirectional CFRP specimens together with the numerical FEM analyses were carried out in order to verify the advantages of such revisions by which the higher true shear strengths were obtained without stress concentration.
