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Fast neutron environments

Hattar, Khalid; Puskar, J.D.; Doyle, Barney L.; Boyce, Brad L.; Buchheit, Thomas; Foiles, Stephen M.; Lu, Ping; Clark, Blythe C.; Kotula, Paul G.; Goods, Steven H.

The goal of this LDRD project is to develop a rapid first-order experimental procedure for the testing of advanced cladding materials that may be considered for generation IV nuclear reactors. In order to investigate this, a technique was developed to expose the coupons of potential materials to high displacement damage at elevated temperatures to simulate the neutron environment expected in Generation IV reactors. This was completed through a high temperature high-energy heavy-ion implantation. The mechanical properties of the ion irradiated region were tested by either micropillar compression or nanoindentation to determine the local properties, as a function of the implantation dose and exposure temperature. In order to directly compare the microstructural evolution and property degradation from the accelerated testing and classical neutron testing, 316L, 409, and 420 stainless steels were tested. In addition, two sets of diffusion couples from 316L and HT9 stainless steels with various refractory metals. This study has shown that if the ion irradiation size scale is taken into consideration when developing and analyzing the mechanical property data, significant insight into the structural properties of the potential cladding materials can be gained in about a week.

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TYPE SAND Report YEAR 2011
DOIOSTI

Ductile failure X-prize

Boyce, Brad L.; Foulk, James W.; Littlewood, David J.; Mota, Alejandro; Ostien, Jakob T.; Silling, Stewart; Spencer, Benjamin W.; Wellman, Gerald W.; Bishop, Joseph E.; Brown, Arthur; Cordova, Theresa E.; Cox, James; Crenshaw, Thomas B.; Dion, Kristin; Emery, John

Fracture or tearing of ductile metals is a pervasive engineering concern, yet accurate prediction of the critical conditions of fracture remains elusive. Sandia National Laboratories has been developing and implementing several new modeling methodologies to address problems in fracture, including both new physical models and new numerical schemes. The present study provides a double-blind quantitative assessment of several computational capabilities including tearing parameters embedded in a conventional finite element code, localization elements, extended finite elements (XFEM), and peridynamics. For this assessment, each of four teams reported blind predictions for three challenge problems spanning crack initiation and crack propagation. After predictions had been reported, the predictions were compared to experimentally observed behavior. The metal alloys for these three problems were aluminum alloy 2024-T3 and precipitation hardened stainless steel PH13-8Mo H950. The predictive accuracies of the various methods are demonstrated, and the potential sources of error are discussed.

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TYPE SAND Report YEAR 2011
DOIOSTI
Results 376–400 of 479
Results 376–400 of 479
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