应力松弛

Abstract(#br)This study reports effects of aspect ratio of test specimens on the stress-strain and stress-relaxation behaviors of polydimethylsiloxane (PDMS) and PDMS composites comprising 5 vol % of micrometer sized Cu powders, Cu(p). PDMS and PDMS-Cu(p) composites of aspect ratio ranging from 0.1 to 0.4 were cyclically loaded in compression at a strain rate of 1.0 × 10 −3 s −1 . Irrespective of the aspect ratio, the PDMS-Cu(p) composites showed higher stress bearing capacity and also absorbed slightly more energy per cycle as compared to pure PDMS.

Abstract(#br)It is shown that visible light irradiation of carbon nanotube (CNT) dispersed polymers may yield both reversible and irreversible changes in measured mechanical stress. While light irradiation of PDMS (polydimethylsiloxane)–CNT composite yields a change of stress level at a fixed strain, which reverts to the original value after the incident light is removed, the RET (reactive ethylene terpolymer)–CNT composite exhibits such reversible characteristics as well as an additional irreversible stress-relaxation response when the composite is first irradiated by light.