stress relaxation

Stress relaxation is then said to have occurred.

To model stress relaxation in glass materials Dowvalter uses the following:

The curvature of the model represent the effects of both creep and stress relaxation.

Vegener et al. use a power series to describe stress relaxation in polyamides:

Stress relaxation describes how polymers relieve stress under constant strain.

Stress relaxation calculations can differ for different materials:

The following non-material parameters all affect stress relaxation in polymers :

It is a common failure mode, and may be contrasted with fatigue, creep, rupture, or stress relaxation.

On the other hand, the Voigt model is good at predicting creep but rather poor at predicting stress relaxation.

(a) Constant strain (a stress relaxation experiment)

This may be because low strength coal tends to deform in and around the face area as mining occurs, resulting in stress relaxation (see below).

Expansins characteristically cause wall stress relaxation and irreversible wall extension (wall creep).

This nonlinearity is described by both stress relaxation and a phenomenon known as creep, which describes how polymers strain under constant stress.

A complementary property is stress relaxation, where a strain is applied and the corresponding stress change is measured.

In stress confinement, which occurs when the laser pulsewidth is much shorter than the stress relaxation time, Eq.

The fiberglass carries a high ultimate tensile strength, behaves elastically, and does not suffer from significant stress relaxation or creep.

However, the elastomeric state is unstable because chains can slip past one another resulting in creep or stress relaxation under static or dynamic load conditions.

In plant cells, the wall-loosening protein named expansin causes wall stress relaxation by loosening the connections between cellulose microfibrils.

Models containing dashpots add a viscous, time dependent, element to the behavior of solids allowing complex behaviors like creep and stress relaxation to be modeled.

In viscoplastic materials, relaxation tests demonstrate the stress relaxation in uniaxial loading at a constant strain.

The advantages of strain control include a better short time response for materials of low viscosity and experiments of stress relaxation are done with relative ease.

Creep and stress relaxation measures the elasticity, viscoelasticity and viscous behaviour of materials under a selected stress and temperature.

Stress relaxation is available using any standard universal test instruments, since their mode of operation is application of strain, while the stress is measured.

Hoechst multiparameter approach: A method that utilizes biaxial stresses and stress relaxation for lifetime prediction and can include seams as well.

Many mechanical properties of polymers have an Arrhenius type relationship with respect to time and temperature (for example, creep, stress relaxation, and tensile properties).