Shape-Memory Polymers (SMPs) have the ability to be deformed and memorize this deformation until an external activation stimulus (e.g., heat) is applied. Therefore, they have attracted great interest in many areas, especially for applications where reconfigurable structures are required (e.g., Shape-Memory (SM) stents or micro air vehicles). Nevertheless, prior to technical application, the effective thermomechanical behavior of SMPs must be thoroughly understood. In the current contribution, an assessment of thermorheological properties of the commercially available polyurethane system ESTANE is presented. Thermorheological properties were investigated using Dynamic Mechanical Thermal Analysis (DMTA) and complementary uniaxial stress relaxation experiments. Upon material parameter optimization, a finite viscoelastic and incompressible material model was used to model experimentally observed viscoelastic properties.

No abstract

No abstract

High Performance Concrete (HPC) and Ultra High Performance Concrete (UHPC) achieve an effective stiffness or strength which allows constructing highly stressed buildings. Following, we present a mechanical characterization technique for HPC and UHPC, using harmonic excitations from 0.1 Hz up to 1 kHz and displacement amplitudes in the micrometer range. The small-amplitude excitations are performed by a high-performance piezo-electric actuator. To validate the experimental workflow, we characterize the mechanical behaviour of Polymethylmethacrylat (PMMA). In this contribution, we present results gained with two different cylindrical sample sizes. By this comparison we shall ensure that geometrical scaling of samples has no influence on the rheological results of the experiments, apart from a change in Signal-to-Noise ratio.