论文信息 - The effect of fibre rotation in ±45° tension tests on measured shear properties

The effect of fibre rotation in ±45° tension tests on measured shear properties

Abstract Non-linear analysis has been carried out on glass/epoxy ±45° tension specimens to quantify the errors involved in deducing the shear stress-strain response from this test. The non-linear geometry effect due to large fibre rotations, large strains and the effects of non-linear shear and transverse material properties are considered. It is shown that at large shear strains the actual ply-level shear stress is much lower than that normally assumed due to the combined effect of fibre rotation and non-linear shear response. There is a large increase in the fibre-direction stress, and this explains the very high values of apparent shear strength which can be obtained with ±45° tension tests. Large transverse compressive stresses can also arise as a result of fibre rotation. However, the errors in shear stress are small at shear strains below about 7%, confirming that the tests are satisfactory for modulus and initial stress-strain measurements.

Michael R Wisnom | M. Wisnom

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