Ductility, recovery and strain rate dependency of an acrylic structural adhesive

The ductility and time-dependent recovery of a ductile acrylic adhesive were investigated in this work. The quasi-static true tensile and compressive strain behaviors were examined at different strain rates, taking large deformations into account. Yield stress, elastic modulus, and failure strain exhibited a logarithmic dependency on increasing strain rate, while yield strain and stiffness after yielding were insensitive to strain rate. High energy-based ductility indices were obtained compared to traditional materials. The time-dependent recovery after unloading depended on loading type (tension or compression), the strain rate of loading, and the strain at unloading. The delayed recovered strain development was modeled using an existing Weibull-based model for creep recovery. The strain after unloading almost fully recovered after 48 h, indicating that no residual deformation caused by damage or plastic flow occurred.