Elastic hysteresis phenomena in ULE and Zerodur optical glasses at elevated temperatures
Elastic hysteresis phenomena were observed in ULE and Zerodur glasses at elevated temperatures up to glass transition. These effects were found under load deformation testing using four-point bending. Permanent creep resulted in Zerodur at 900/degree/C and in ULE at 1000/degree/C. The deformation was monitored at mid-span of the samples with a capacitance-type transducer having 0.01 micrometer resolution. These hysteresis effects may be classified as elastic bimodulus between loading and unloading; that is, two different elastic moduli were observed between loading and unloading. Upon complete unloading, a minimal deformation state promptly returned, indicating little or no viscoelastic creep. The hysteresis effect may be attributed to a change in glass structure as a function of stress state. A description of the test apparatus and procedure, test results for both glasses at several elevated temperatures, and an elementary discussion of continuum theory of constitutive behavior are included. 6 refs., 9 figs.
- Research Organization:
- EG and G Idaho, Inc., Idaho Falls (USA)
- DOE Contract Number:
- AC07-76ID01570
- OSTI ID:
- 6565709
- Report Number(s):
- EGG-M-88094; CONF-880887-28; ON: DE89005183
- Resource Relation:
- Conference: 32. international technical symposium on optical and opto-electronic applied sciences and engineering, San Diego, CA, USA, 14 Aug 1988; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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