EXPERIMENTAL TEACHING EXPLORATION OF LINEAR VISCOELASTIC MATERIALS BASED ON DIGITAL IMAGE CORRELATION

The theory of linear viscoelasticity is an important content of solid mechanics principle course. The current experimental teaching generally uses electronic universal testing machine to carry out uniaxial tensile experiments on linear viscoelastic materials, and the experimental results are not intuitive enough. The digital image correlation method is a high-precision full-field strain measurement method, which has been widely used in the field of experimental mechanics in recent years. Taking solid propellant, a linear viscoelastic material, as an example, this paper designs a uniaxial tensile experiment of linear viscoelastic material by digital image correlation method, and the experimental results are visualized in a more intuitive manner, which is helpful to mobilize students' enthusiasm. The experiment shows that the material strain measured by the solid propellant unidirectional tensile method specified in the national military standard is significantly different, and an experimental teaching seminar is designed to guide students to conduct in-depth analysis, which is helpful to deepen the understanding of linear viscoelastic theory.