483 research outputs found
Additive Manufacturing Machine/Process Qualification
No abstract availabl
Overview of Flight Certification Methodology for Additive Manufacturing
No abstract availabl
Applications of Automation Methods for Nonlinear Fracture Test Analysis
As fracture mechanics material testing evolves, the governing test standards continue to be refined to better reflect the latest understanding of the physics of the fracture processes involved. The traditional format of ASTM fracture testing standards, utilizing equations expressed directly in the text of the standard to assess the experimental result, is self-limiting in the complexity that can be reasonably captured. The use of automated analysis techniques to draw upon a rich, detailed solution database for assessing fracture mechanics tests provides a foundation for a new approach to testing standards that enables routine users to obtain highly reliable assessments of tests involving complex, non-linear fracture behavior. Herein, the case for automating the analysis of tests of surface cracks in tension in the elastic-plastic regime is utilized as an example of how such a database can be generated and implemented for use in the ASTM standards framework. The presented approach forms a bridge between the equation-based fracture testing standards of today and the next generation of standards solving complex problems through analysis automation
Forward Considerations in Methodologies for Qualification and Certification of Additively Manufactured Parts
No abstract availabl
Metallic Laser Beam Powder Bed Fusion Process Qualification
No abstract availabl
Qualification & Certification of Additively Manufactured Parts for NASA Applications
No abstract availabl
A Framework to Establish Additive Manufacturing Certification
No abstract availabl
Methodology for Substantiation of Design Values in Additive Manufacturing: Importance of Equivalence Methods
No abstract availabl
Applications of Automation Methods for Nonlinear Fracture Test Analysis
Using automated and standardized computer tools to calculate the pertinent test result values has several advantages such as: 1. allowing high-fidelity solutions to complex nonlinear phenomena that would be impractical to express in written equation form, 2. eliminating errors associated with the interpretation and programing of analysis procedures from the text of test standards, 3. lessening the need for expertise in the areas of solid mechanics, fracture mechanics, numerical methods, and/or finite element modeling, to achieve sound results, 4. and providing one computer tool and/or one set of solutions for all users for a more "standardized" answer. In summary, this approach allows a non-expert with rudimentary training to get the best practical solution based on the latest understanding with minimum difficulty.Other existing ASTM standards that cover complicated phenomena use standard computer programs: 1. ASTM C1340/C1340M-10- Standard Practice for Estimation of Heat Gain or Loss Through Ceilings Under Attics Containing Radiant Barriers by Use of a Computer Program 2. ASTM F 2815 - Standard Practice for Chemical Permeation through Protective Clothing Materials: Testing Data Analysis by Use of a Computer Program 3. ASTM E2807 - Standard Specification for 3D Imaging Data Exchange, Version 1.0 The verification, validation, and round-robin processes required of a computer tool closely parallel the methods that are used to ensure the solution validity for equations included in test standard. The use of automated analysis tools allows the creation and practical implementation of advanced fracture mechanics test standards that capture the physics of a nonlinear fracture mechanics problem without adding undue burden or expense to the user. The presented approach forms a bridge between the equation-based fracture testing standards of today and the next generation of standards solving complex problems through analysis automation
Supersymmetric Unification Without Low Energy Supersymmetry And Signatures for Fine-Tuning at the LHC
The cosmological constant problem is a failure of naturalness and suggests
that a fine-tuning mechanism is at work, which may also address the hierarchy
problem. An example -- supported by Weinberg's successful prediction of the
cosmological constant -- is the potentially vast landscape of vacua in string
theory, where the existence of galaxies and atoms is promoted to a vacuum
selection criterion. Then, low energy SUSY becomes unnecessary, and
supersymmetry -- if present in the fundamental theory -- can be broken near the
unification scale. All the scalars of the supersymmetric standard model become
ultraheavy, except for a single finely tuned Higgs. Yet, the fermions of the
supersymmetric standard model can remain light, protected by chiral symmetry,
and account for the successful unification of gauge couplings. This framework
removes all the difficulties of the SSM: the absence of a light Higgs and
sparticles, dimension five proton decay, SUSY flavor and CP problems, and the
cosmological gravitino and moduli problems. High-scale SUSY breaking raises the
mass of the light Higgs to about 120-150 GeV. The gluino is strikingly long
lived, and a measurement of its lifetime can determine the ultraheavy scalar
mass scale. Measuring the four Yukawa couplings of the Higgs to the gauginos
and higgsinos precisely tests for high-scale SUSY. These ideas, if confirmed,
will demonstrate that supersymmetry is present but irrelevant for the hierarchy
problem -- just as it has been irrelevant for the cosmological constant problem
-- strongly suggesting the existence of a fine-tuning mechanism in nature.Comment: Typos and equations fixed, references adde
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