Posted by(작성하신 분) BOUFALA KHALED ( June 14, 2001 at 23:41:56: )
In Reply to(원문) : Re: stress relaxation
posted by(원문 작성자) : rex on November 01, 2000 at 15:51:42:
: 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