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Large motion high cycle high speed optical fibers for space based applications

Stromberg, Peter G.; Tandon, Rajan T.; Gibson, Cory S.; Reedlunn, Benjamin R.; Rasberry, Roger D.; Rohr, Garth R.

Future remote sensing applications will require higher resolution and therefore higher data rates (up to perhaps 100 gigabits per second) while achieving lower mass and cost. A current limitation to the design space is high speed high bandwidth data does not cross movable gimbals because of cabling issues. This requires the detectors to be off gimbal. The ability to get data across the gimbal would open up efficiencies in designs where the detectors and the electronics can be placed anywhere on the system. Fiber optic cables provide light weight high speed high bandwidth connections. Current options are limited to 20,000 cycles as opposed to the 1,000,000 cycles needed for future space based applications. To extend this to the million+ regime, requires a thorough understanding of the failure mechanisms and the materials, proper selection of materials (e.g., glass and jacket material) allowable geometry changes to the cable, radiation hardness, etc.

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TYPE SAND Report YEAR 2014
OSTIDOI

Proposed Testing to Assess the Accuracy of Glass-To-Metal Seal Stress Analyses

Chambers, Robert S.; Emery, John M.; Tandon, Rajan T.; Antoun, Bonnie R.; Stavig, Mark E.; Newton, Clay S.; Gibson, Cory S.; Bencoe, Denise N.

The material characterization tests conducted on 304L VAR stainless steel and Schott 8061 glass have provided higher fidelity data for calibration of material models used in Glass - T o - Metal (GTM) seal analyses. Specifically, a Thermo - Multi - Linear Elastic Plastic ( thermo - MLEP) material model has be en defined for S S304L and the Simplified Potential Energy Clock nonlinear visc oelastic model has been calibrated for the S8061 glass. To assess the accuracy of finite element stress analyses of GTM seals, a suite of tests are proposed to provide data for comparison to mo del predictions.

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TYPE SAND Report YEAR 2014
OSTIDOI

Characterization & Modeling of Materials in Glass-To-Metal Seals: Part I

Chambers, Robert S.; Emery, John M.; Tandon, Rajan T.; Antoun, Bonnie R.; Stavig, Mark E.; Newton, Clay S.

To support higher fidelity modeling of residual stresses in glass-to-metal (GTM) seals and to demonstrate the accuracy of finite element analysis predictions, characterization and validation data have been collected for Sandia’s commonly used compression seal materials. The temperature dependence of the storage moduli, the shear relaxation modulus master curve and structural relaxation of the Schott 8061 glass were measured and stress-strain curves were generated for SS304L VAR in small strain regimes typical of GTM seal applications spanning temperatures from 20 to 500 C. Material models were calibrated and finite element predictions are being compared to measured data to assess the accuracy of predictions.

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TYPE SAND Report YEAR 2014
OSTIDOI
Results 26–50 of 91
Results 26–50 of 91