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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 307 records · Page 17

Research in structures and materials for future space transportation systems - An overview

The paper provides a review of some of the advances of the past decade in structures and materials that have application to future space transportation systems. The paper concentrates on metallic thermal protection systems and structures which could provide the structural efficiency, reliability, and durability dictated by future space utilization requirements. The need for completely reusable, on-board cryogenic fuel tanks is cited as the most challenging technical opportunity and potential thermostructural concepts for tanks are identified. Other critical areas needing technology advances are discussed. Finally, the unique research opportunities offered by the Shuttle Orbiter experiments program for testing structures and thermal protection systems are explored.

Kelly, H. N.↗

Tensile Properties of Some Structural Sheet Materials Under Rapid-Heating Conditions

The results of the NACA tests to determine the tensile strength of some structural sheet materials heated to failure at temperature rates from 0.2 deg. F to 100 deg F per second under constant load conditions are reviewed . Yield and rupture stresses obtained under rapid-heating conditions are compared with the results of conventional elevated-temperature tensile tests. The relation between rapid-heating tests, short-time creep tests, and conventional creep tests is discussed . The application of a phenomenological theory for calculating rapid-heating curves is shown. Methods are given for predicting yield and rupture stresses and temperatures from master curves and temperature-rate parameters

Heimerl, George J.↗

Materials with structural hierarchy

The role of structural hierarchy in determining bulk material properties is examined. Dense hierarchical materials are discussed, including composites and polycrystals, polymers, and biological materials. Hierarchical cellular materials are considered, including cellular solids and the prediction of strength and stiffness in hierarchical cellular materials.

Lakes, Roderic↗

Orbiter TPS development and certification testing at the NASA/JSC 10 MW Atmospheric Reentry Materials and Structures Evaluation Facility

Thermal performance of the Space Shuttle Orbiter Thermal Protection System (TPS) has been verified by extensive ground testing at the NASA/JSC 10 MW Atmospheric Reentry Materials and Structures Evaluation Facility (ARMSEF). Major test programs have included current TPS materials (RSI, RCC and ablators) and advanced TPS materials (AFRSI and FRCI-12). Testing by electrically heating a gas mixture simulating air and expanding it (supersonically or hypersonically) through channel or conical nozzles has produced simulated thermal and pressure environments on models representative of the Orbiter TPS acreage and penetration regions. Tests have established Orbiter TPS thermal design requirements, verified Orbiter TPS thermal performance, and supported Orbiter TPS flight anomaly investigations and resolutions.

Rochelle, W. C.↗

Structures and mechanisms

Structures, materials, and mechanisms is one of the older technologies in the aerospace business. The Structures, Materials, and Mechanisms Panel was divided into the four basic categories that fit the overall responsibilities of the panel: materials, mechanisms, structural design, and analysis.

Purdy, D.↗

Progressive failure analysis of fibrous composite materials and structures

A brief description is given of the modifications implemented in the PAFAC finite element program for the simulation of progressive failure in fibrous composite materials and structures. Details of the memory allocation, input data, and the new subroutines are given. Also, built-in failure criteria for homogeneous and fibrous composite materials are described.

Bahei-El-din, Yehia A.↗

Experimental measurement of passive material and structural damping for flexible space structures

Among the design objectives for large space structures are the maintenance of tight dimensional tolerance and the reduction of settling time after disturbance input. Two options are under consideration for the design of flexible structures to meet these objectives, including an active control option and a passive control option. In connection with both options, it is necessary to include material and structural damping in the design. A description is presented of the results of an experimental investigation of the damping of metallic and fibrous composite materials, taking into account also the analytical modeling and experimental verification of frictional damping schemes. To demonstrate how material and frictional damping can be combined, a simple structural optimization is performed, indicating the potential for significant savings in mass by the addition of frictional dampers.

Crawley, E. F.↗

Materials and structural aspects of advanced gas-turbine helicopter engines

Advances in materials, coatings, turbine cooling technology, structural and design concepts, and component-life prediction of helicopter gas-turbine-engine components are presented. Stationary parts including the inlet particle separator, the front frame, rotor tip seals, vanes and combustors and rotating components - compressor blades, disks, and turbine blades - are discussed. Advanced composite materials are considered for the front frame and compressor blades, prealloyed powder superalloys will increase strength and reduce costs of disks, the oxide dispersion strengthened alloys will have 100C higher use temperature in combustors and vanes than conventional superalloys, ceramics will provide the highest use temperature of 1400C for stator vanes and 1370C for turbine blades, and directionally solidified eutectics will afford up to 50C temperature advantage at turbine blade operating conditions. Coatings for surface protection at higher surface temperatures and design trends in turbine cooling technology are discussed. New analytical methods of life prediction such as strain gage partitioning for high temperature prediction, fatigue life, computerized prediction of oxidation resistance, and advanced techniques for estimating coating life are described.

Freche, J. C.↗

(abstract) Oblique Insonification Ultrasonic NDE of Composite Materials for Space Applications

In recent years, a great deal of research has been exerted to developing NDE methods for the characterization of the material properties of composites as well as other space structural materials. The need for information about such parameters as the elastic properties, density, and thickness are critical to the safe design and operation of such structural materials. Ultrasonics using immersion methods has played an important role in these efforts due to its capability, cost effectiveness, and ease of use. The authors designed a series of ultrasonic oblique insonification experiments in order to develop a practical field applicable NDE method for space structures.

ultrasonic composites nondestructive evaluation ND↗

Optimization of a Solver for Computational Materials and Structures Problems on NVIDIA Volta and AMD Instinct GPUs

The Scalable Implementation of Finite Elements by NASA (ScIFEN) is a software package developed to solve complex computational materials and structures problems using the finite element method (FEM). In this paper, we describe optimization techniques to speed up the linear solver computation that occurs within the ScIFEN application. We consider GPUs from two different vendors, NVIDIA and AMD as our target platforms for optimization and highlight differences in performance and optimization techniques. The NVIDIA GPU Volta V100 is used in the Summit system deployed at Oak Ridge National Laboratory, and the new exascale system, Frontier, will be using AMD Radeon Instinct GPU. We evaluated the performance of various optimization techniques on test matrices, ranging in size from100K to 4M, that are representative of ScIFEN applications. The linear solver computation is memory-bound on both GPUs. Our experiments show that on the NVIDIA GPU we obtained up to79%of the theoretical peak bandwidth, while the AMD GPU achieved 59%. Overall, the NVIDIA V100 GPU outperforms the AMD MI 25 GPU1. We observed an overall speedup of up to37X on an NVIDIA V100 compared to an Intel Skylake 12-coremachine. The solver for a 4M degree of freedom system took under 2.5 seconds.

Mohammad Zubair↗

Reliability of structural brittle materials

Traditionally, the use of brittle materials has been avoided in demanding structural applications because of their unreliability. They have been used however, due to other desirable properties, in nonstructural applications or where the mechanical load is minimal. The most common method utilized today for the design approach of brittle materials is the probabilistic, which takes into consideration the flaw and stress distribution within the brittle material. It does not take into consideration the fracture mechanics effect of strength degradation while aging under a mechanical load. This project will combine the two methods, probabilistic and fracture mechanics, into a more reliable design method for brittle materials.

Hall, W. B.↗

Composite materials for structures on planetary surfaces

The physical and mechanical properties of advanced composite materials as related to their use in structures on planetary surfaces are reviewed. Polymer matrix composites are recommended as the best materials in the first exploration stages. Achievement of mechanical properties, physical properties, improved processability, and ease of assembly required on planetary surfaces depends on the tailorability of composites.

Radford, Donald W.↗

A multimodal large language model for materials science

Understanding and predicting the properties of inorganic materials is crucial for accelerating advancements in materials science and driving applications in energy, electronics and beyond. Integrating material structure data with language-based information through multimodal large language models (LLMs) offers great potential to support these efforts by enhancing human–artificial intelligence interaction. However, a key challenge lies in integrating atomic structures at full resolution into LLMs. In this work, we introduce MatterChat, a versatile structure-aware multimodal LLM that unifies material structural data and textual inputs into a single cohesive model. MatterChat uses a bridging module to effectively align a pretrained universal machine learning interatomic potential with a pretrained LLM, reducing training costs and enhancing flexibility. Our results demonstrate that MatterChat greatly improves performance in material property prediction and human–artificial intelligence interaction, surpassing general-purpose LLMs such as GPT-4. We also demonstrate its usefulness in applications such as more advanced scientific reasoning and step-by-step material synthesis.

Tang, Yingheng [Lawrence Berkeley National Laborat↗

Nondestructive evaluation/characterization of composite materials and structures using the acousto-ultrasonic techniques

This paper introduces the nature and the underlying rational of the acousto-ultrasonic stress wave factor technique and some of its applications to composite materials and structures. Furthermore, two examples of successful application of the acousto-ultrasonic technique are presented in detail. In the first example, the acousto-ultrasonic technique is used to evaluate the adhesive bond strength between rubber layers and steel plates, and in the seocnd example the tehcnique is used to monitor progressive damage in wire rope.

Dos Reis, H. L. M.↗