Creep Mode i.e., Temperature-Flexural Storage Modulus Plots

5 Creep Mode (i.e., Temperature-Flexural Storage Modulus Plots) 

Creep is defined as a long-term property measured by deforming a sample at a constant stress and monitoring the flow (strain) over a period of time. Viscoelastic materials flow or deform if subjected to loading (stress). In a creep experiment, a constant stress is applied and the resulting deformation measured as a function of temperature and time. Just as stress relaxation is an important property to structural engineers and polymer scientists, so is creep behavior. 

The elastic modulus is a quantitative measure of the stiffness or rigidity of a material. For example, for homogeneous isotropic substances in tension, the strain (e) is related to the applied stress (o ) by the equation E = o /e, where E is defined as the elastic modulus. A similar definition of shear modulus (g) applies if the strain is shear. 

The creep mode is used for the measurement of flow at constant stress to determine the load-bearing stability of materials, which is a key to prediction of product performance. The CTeep mode is used to measure sample creep (strain) as a function of time and temperature at a selected stress. Using the isothermal step method, the sample 

FIGURE 2.18 Flexible storage modulus and loss properties of fiber-reinforced vinyl ester composite. 

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