Dynamic mechanical analysis (DMA)

Dynamic mechanical analysis (DMA) is a mechanical testing method used to characterize material properties as a function of temperature, time, frequency, stress, and atmosphere, or a combination of these parameters.

DMA measures parameters for stiffness and damping. These are reported as moduli (stiffness) and loss tangent (damping). The moduli can be further divided into the storage modulus (E’) and loss modulus (E’’), which are the elastic and viscous components of the material, respectively. The ratio of loss modulus to storage modulus is a measure of the material's damping capacity.

DMA can be used to study the following properties:

• Viscoelastic properties (E', E'', tan(δ))

• Glass transition temperature (T_g)

• Secondary transitions (β & γ)

• Crystallization

• Melting

• Curing kinetics

• Damping

• Creep and stress relaxation

• Mechanical properties (especially useful for small/complex samples)

• Long-term behaviour with Time-Temperature Superposition

The most common deformation modes are tensile, bending (3-point and cantilever), compression, and shear.

The chosen deformation mode, conditions, and material properties selected for study will determine the difficulty and cost of the analysis.