Testing Procedure
Experimental evaluation of elastomeric bonding agents establishes the physical properties required for accurate structural simulation. To achieve this, silicone adhesive characterization measures the stress-strain behavior and viscoelastic properties of the uncured and cured material. This process defines the stiffness, strength, and thermal expansion limits of the polymer.
Mechanical Testing
Tensile testing of dumbbell specimens is performed to record the hyperelastic response under large deformation. During silicone adhesive characterization, engineers apply high-precision extensometers to capture the true strain without the influence of grip slippage. These tests are repeated at different displacement rates to characterize the strain-rate sensitivity of the adhesive.
Environmental Behavior
Environmental chambers are used to evaluate how different temperatures and moisture levels affect the properties of the bond. Exposure to elevated temperatures can cause the material to soften, while prolonged moisture exposure might degrade the adhesion at the interface. Analysts measure the shifts in the glass transition temperature of the polymer to quantify these thermal effects.
This ensures that the adhesive continues to meet the design specifications under harsh operating conditions.
Model Validation
The collected experimental data is fitted to constitutive material models, such as Neo-Hookean or Ogden formulations. This fitting ensures that the finite element models of the assembly can simulate the adhesive behavior under complex load cases. The resulting parameters are stored in a database for future design reference.
