Posted by(작성하신 분) rex ( November 01, 2000 at 15:51:42: )
In Reply to(원문) : stress relaxation
posted by(원문 작성자) : 김동호 on October 27, 2000 at 15:58:35:
Stress Relaxation (definition)
Test by decreasing stress with constant strain
over a given time interval. (Viscoelastic response.)
Creep (definition)
The progressive relaxation of a given rubber
material while it under stress. This relaxation
eventually results in permanent deformation or
"set"
The stress relaxation test is increasingly used
worldwide to quantify the elastic behavior of
polymers and rubber compounds. Stress relaxation
data provides information on compound mixing and
processing properties. In addition stress relaxation
is used as a polymer development tool and as a
control on incoming polymers. Normally the stress
relaxation test is performed at the end of a
standard viscosity test. The rotor is stopped,
and the torque decay rate is measured.
Most commercial Monney Viscometers normally
record stress relaxation, measuring the amount
of stress energy (resilience) remains in a sample
after the spinning rotor is stopped. Plasticity
is graphed and recorded in inch pounds (dNM) or
else.
References
D1630-94 Standard Test Method for Rubber Property-Abrasion Resistance (Footwear Abrader)
D1646-99 Standard Test Methods for Rubber-Viscosity, Stress Relaxation, and Pre-Vulcanization Characteristics (Mooney Viscometer)]
D6048-96 Standard Practice for Stress Relaxation Testing of Raw Rubber, Unvulcanized Rubber Compounds, and Thermoplastic Elastomers
D6147-97 Test Method for Vulcanized Rubber and Thermoplastic Elastomer-Determination of Force Decay (Stress Relaxation) in Compression