Assessment of Sandwich Beam in Three-Point Bending for Measuring Adhesive Shear Modulus
J M. He, Martin Chiang, Donald L. Hunston
A finite element analysis (FEA) was conducted to examine the feasibility of determining the shear modulus of an adhesive in a bonded geometry using a three-point bending test on a sandwich beam specimen. This specimen consists of two substrate bars bonded together with the adhesive. The results were compared with predictions from two analytical solutions for this geometry to determine the impact of the assumptions that are made in these analyses. Because there is an interest in using this test to characterize viscoelastic properties of the adhesive, the range of geometry variables that can be tested in standard viscoelastic equipment is of particular importance. The analyses were used to calculate adhesive properties from experiments on a sandwich beam, but the results were significantly different than the values obtained with other experiments on bulk samples of the adhesive. To examine possible explanations for these differences, a sensitivity analysis was conducted to explore the effects of experimental variables, such as interfacial debonding or variations in bond thickness. Some possible reasons for the differences are discussed, but none are completely satisfactory. Until an explanation is found, the three-point bending test using a sandwich beam specimen is not a useful test method at least for the range of geometries examined here.
Journal of Engineering Materials and Technology - Transactions of the ASME
, Chiang, M.
and Hunston, D.
Assessment of Sandwich Beam in Three-Point Bending for Measuring Adhesive Shear Modulus, Journal of Engineering Materials and Technology - Transactions of the ASME, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851773
(Accessed February 23, 2024)