Engineering topics
Publications and source records attributed to Richardson, Bradley.
There is no currently available, open-source, easily adapted test suite for checking a compiler's conformance to the Fortran Standard. The main innovation of this software is in the framework to make the test suite apply to a new compiler. Making it open-source will enable community contributions of the test cases. Single organization construction of a comprehensive test suite is something that would be financially infeasible.
This document specifies an interface to support the parallel features of Fortran, named the Parallel Runtime Interface for Fortran (PRIF). PRIF is a proposed solution in which the runtime library is responsible for coarray allocation, deallocation and accesses, image synchronization, atomic operations, events, and teams. In this interface, the compiler is responsible for transforming the invocation of Fortran-level parallel features into procedure calls to the necessary PRIF procedures. The interface is designed for portability across shared- and distributed-memory machines, different operating systems, and multiple architectures. Implementations of this interface are intended as an augmentation for the compiler's own runtime library. With an implementation-agnostic interface, alternative parallel runtime libraries may be developed that support the same interface. One benefit of this approach is the ability to vary the communication substrate. A central aim of this document is to define a parallel runtime interface in standard Fortran syntax, which enables us to leverage Fortran to succinctly express various properties of the procedure interfaces, including argument attributes.
Additive manufacturing (AM), in both polymer and metal, has advanced to the point where it can significantly facilitate robot and remote system design and implementation. Properly used AM creates features and capabilities otherwise not possible in machined or cast products. AM design rules are still being developed and must be applied differently based on the process and purpose of the final component, but progress is being made in practical implementation. Polymer-based AM has been commercially available for quite some time and is regularly used for prototyping and test fitting parts before they are fabricated from metal or produced in low production quantity parts that do not require high structural strength. Metal printing processes are more diverse than polymer print processes. Both polymer and metal printing systems can be used to make parts or complete systems for robotics. Two implementation examples that illustrate the possibilities and identify issues that remain in metal printing are: a dual arm hydraulic manipulator and a distal link of an excavator arm. The dual arm hydraulic manipulator was printed in titanium using an e-beam fusing process. All hydraulics and electrical cabling passageways were printed into the manipulator; there are no external hoses or cables. The distal link of an excavator arm was printed using a wire-fed metal inert gas process. The excavator was then used for digging as part of an equipment exposition validating the structural integrity of the printed part. (authors)
Tooling is a primary target for current additive manufacturing (AM), or 3D printing, technology because of its rapid prototyping capabilities. Molds of many sizes and shapes have been produced for a variety of industries. However, large tooling remained out of reach until the development of large-scale composite AM manufacturing processes like the Big Area Additive Manufacturing (BAAM) system. The Department of Energy's Oak Ridge National Laboratory (ORNL) worked with TPI Composites to use the BAAM system to fabricate a wind turbine blade mold. The fabricated wind turbine blade mold was produced in 16 additively manufactured sections, was 13 meters long, had heating channels integrated into the design, and was mounted into a steel frame post fabrication. This research effort serves as a case study to examine the technological impacts of AM on wind turbine blade tooling and evaluate the efficacy of this approach in utility scale wind turbine manufacturing.
The objective of this project was to explore the utility of Big Area Additive Manufacturing (BAAM) for low cost manufacturing of wind turbine molds. Engineers at Oak Ridge National Laboratory (ORNL) and TPI Composites (TPI) collaborated to design and manufacture a printed mold that can be used for resin infusion of wind turbine components. Specific focus was on required material properties (operating temperatures and pressures, coefficient of thermal expansion (CTE), thermal conductivity), surface finish (accuracy and coatings) and system integration (integrated vacuum ports, and heating element). The project began with a simple proof of principle components, targeting surface coatings and material properties for printing a small section (approximately 4’ x 4’ x 2’) of a mold. Next, the second phase scaled up and integrated with the objective of capturing all of the necessary components (integrated heating to accelerate cure time, and vacuum, sealing) for resin infusion on a mold of significant size (8’ x 20’ x 6’).