Nonlinear numerical analysis of the V-notched rail shear test specimen

• Published in: Polymer testing 2018-02, Vol.65, p.44-53
• Main Authors: Taheri-Behrooz, Fathollah, Moghaddam, Hosein Salehi
• Format: Article
• Language: English
• Subjects: Error correction; Finite element analysis; Finite element method; In-plane shear properties; Nonlinear analysis; Nonlinearity; Notches; Numerical analysis; Shear modulus; Shear properties; Shear strain; Shear strength; Shear stress; Shear testing of composites; Shear tests; Strain distribution; Stress concentration; Stress-strain curves; Stress-strain relationships; Uncertainty; Uncertainty analysis; V-notched rail shear test method
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/j.polymertesting.2017.11.008

V-Notched rail (VNR) shear test is a fairly recent shear test method and has been standardized as ASTM D7078. In the present research, shear properties of glass/epoxy specimens were evaluated by the VNR test method and compared with the three-rail shear test results. Shear modulus obtained by the two test methods are almost the same, however, VNR gives the shear strength around 36% greater than the three-rail test. Considering the observed nonlinearity in the experimental shear stress-strain diagram, nonlinear finite element analysis of the VNR specimen was performed by developing UMAT subroutine. Numerical analysis showed such non-uniformity in the shear stress and shear strain distribution between the notches. To take into account the non-uniformity, a correction factor for shear modulus and shear strength are introduced to correct about 8% and 4% error in the shear strength and shear modulus, respectively. The effect of some errors which are likely to occur during the test, was also studied. Finally, uncertainty analysis was employed to evaluate the quality of measurement. Uncertainty values are determined as 3.6% of the shear strength and 1.7% of the shear modulus measured value. •Nonlinear finite element analysis of the V-notched rail shear test specimen have been performed.•Application of the correction factor is necessary to calculated shear strength and shear modulus.•Uncertainty analysis in measurement provides a quantitative indication of the quality of the results.