1975 Volume 24 Issue 263 Pages 776-782
A new type of Biaxial testing machine utilizing flat specimens has been assembled to investigate the mechanical behaviours and failure strength of glass cloth reinforced plastics under a combined tension-compression biaxial stress state. This machine is composed of the tension and compression devices which have the mechanism of preventing shifting of the center of a specimen during biaxial test.
The structure of this machine is described in the paper. The experimental results of failure strength of glass cloth reinforced plastics under a biaxial stress state are compared with those caluculated by using the interaction formula. The observed values were found not to agree well with the calculated results, and a criterion such as Hill's was not applicable to this case.
From the consideration of the failure mode, some suggestions have been made to obtain the way to find a more exact failure criterion.