5.1 This method provides a simple means of characterizing the cure behavior of a thermosetting resin specimen that is a representation of a composite part. The diameter of the specimen is approximately 38 mm and the thickness ranges from 2.6 to 3.2 mm. This corresponds to a sample volume of approximately 3 to 4 cm³. The data may be used for quality control, research and development, and verifying the cure within processing equipment including autoclaves.

5.2 Dynamic mechanical testing provides a sensitive method for determining cure characteristics by measuring the elastic and loss moduli as a function of temperature or time, or both. Plots of cure behavior and tan delta of a material provide graphical representation indicative of cure behavior under a specified time-temperature profile. The presence of fibers within the resin may change the dynamic properties measured within a material. However, it is still possible to compare different resins with the same fiber structure and obtain the relative difference due to the resin cure properties.

5.3 This method can be used to assess the following:

5.3.1 Cure behavior, as well as changes as a function of temperature or time, or both,

5.3.2 Processing behavior, as well as changes as a function of temperature or time, or both,

5.3.3 The effects of processing treatments,

5.3.4 Relative resin behavioral properties, including cure behavior, damping and impact resistance,

5.3.5 The effects of reinforcement on cure.

5.3.6 The effects of materials used to bond the resin and reinforcement,

5.3.7 The effect of formulation additives that might affect processability or performance.

5.4 This provides a method to assess the cure properties of a thermosetting resin containing woven fiber or other reinforcing materials.

5.5 This method is valid for a wide range of oscillation frequencies typically from 0.002 to 50 Hz.

Note 1: It is recommended that low-frequency test conditions, generally 1 to 2 Hz, be used to generate more definitive cure-behavior information. Slower frequencies will miss important cure properties. Faster frequencies will reduce sensitivity to cure.