Publications

Results 26–46 of 46
Skip to search filters

Accelerated testing of metal foil tape joints and their effect of photovoltaic module reliability

Proceedings of SPIE - The International Society for Optical Engineering

Sorensen, N.R.; Quintana, Michael A.; Puskar, J.D.; Lucero, Samuel J.

A program is underway at Sandia National Laboratories to predict long-term reliability of photovoltaic (PV) systems. The vehicle for the reliability predictions is a Reliability Block Diagram (RBD), which models system behavior. Because this model is based mainly on field failure and repair times, it can be used to predict current reliability, but it cannot currently be used to accurately predict lifetime. In order to be truly predictive, physics-informed degradation processes and failure mechanisms need to be included in the model. This paper describes accelerated life testing of metal foil tapes used in thin-film PV modules, and how tape joint degradation, a possible failure mode, can be incorporated into the model. © 2009 SPIE Victor Karpov.

More Details
TYPE Conference YEAR 2009
ScopusOSTI

Microstructure-based approach for predicting crack initiation and early growth in metals

Battaile, Corbett C.; Bartel, Timothy J.; Reedy, Earl D.; Cox, James C.; Foulk, James W.; Puskar, J.D.; Boyce, Brad B.; Emery, John M.

Fatigue cracking in metals has been and is an area of great importance to the science and technology of structural materials for quite some time. The earliest stages of fatigue crack nucleation and growth are dominated by the microstructure and yet few models are able to predict the fatigue behavior during these stages because of a lack of microstructural physics in the models. This program has developed several new simulation tools to increase the microstructural physics available for fatigue prediction. In addition, this program has extended and developed microscale experimental methods to allow the validation of new microstructural models for deformation in metals. We have applied these developments to fatigue experiments in metals where the microstructure has been intentionally varied.

More Details
TYPE SAND Report YEAR 2009
OSTIDOI

Development of joining processes and fabrication of US first wall qualification mockups for ITER

Proposed for publication in Fusion Engineering Design.

Puskar, J.D.; Watson, Roger M.; Ulrickson, M.A.

We report here the fabrication processes used to manufacture US Party Team First Wall Qualification Mockups along with the detailed microstructural characterization and mechanical properties of the Be/CuCrZr/316L HIP bonds. A companion submission to this conference describes details of the PMTF heat flux testing and the performance of the first US FWQM.

More Details
TYPE Journal Article YEAR 2009
OSTI

Code case validation of Impulsively Loaded EDS subscale vessel

American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP

Yip, Mien Y.; Haroldsen, Brent L.; Puskar, J.D.

The Explosive Destruction System (EDS) was developed by Sandia National Laboratories for the US Army Product Manager for Non-Stockpile Chemical Materiel (PMNSCM) to destroy recovered, explosively configured,chemical munitions. PMNSCM currently has five EDS units that have processed over 850 items. The system uses linear and conical shaped charges to open munitions and attack the burster followed by chemical treatment of the agent. The main component of the EDS is a stainless steel, cylindrical vessel, which contais the explosion and the subsequent chemical treatment. Extensive modeling and testing have been, and continue to be used, to design and qualify the vessel for different applications and conditions. This has included explosive overtests using small, geometrically scaled vessels to study overloads, plastic deformation, and failure limits. Recently the ASME Task Group on Impulsively Loaded Vessels has developed a Code Case under Section VIII Division 3 of the ASME Boiler and Pressure Vessel Code for the design of vessel like the EDS. In this article, a representative EDS subscale vessel is investigated against the ASME Design Codes for vessels subjected to impulsive loads. Topics include strain-based plastic collapse, fatigue and fracture analysis, and leak-before-burst. Vessel design validation is based on model results, where the high explosive (HE) pressure histories and subsequent vessel response (strain histories) are modeled using the analysis codes CTH and LSDYNA, respectively. Copyright © 2008 by ASME.

More Details
TYPE Conference YEAR 2008
ScopusOSTIDOI

Understanding the microstructure and properties of components fabricated by Laser Engineered Net Shaping (LENS)

Materials Research Society Symposium - Proceedings

Griffith, M.L.; Ensz, M.T.; Puskar, J.D.; Robino, C.V.; Brooks, J.A.; Philliber, J.A.; Smugeresky, J.E.; Hofmeister, W.H.

Laser Engineered Net Shaping (LENS) is a novel manufacturing process for fabricating metal parts directly from Computer Aided Design (CAD) solid models. The process is similar to rapid prototyping technologies in its approach to fabricate a solid component by layer additive methods. However, the LENS technology is unique in that fully dense metal components with material properties similar to wrought materials can be fabricated. The LENS process has the potential to dramatically reduce the time and cost required realizing functional metal parts. In addition, the process can fabricate complex internal features not possible using existing manufacturing processes. The real promise of the technology is the potential to manipulate the material fabrication and properties through precision deposition of the material, which includes thermal behavior control, layered or graded deposition of multi-materials, and process parameter selection.

More Details
TYPE Conference YEAR 2000
ScopusOSTI
Results 26–46 of 46
Results 26–46 of 46