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Material Strength (material + strength)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Impact of Recrystallization Defects on the High Temperature Strength of PM 3030

ADVANCED ENGINEERING MATERIALS, Issue 1-2 2009
Michel NganbeArticle first published online: 19 FEB 200
The paper focuses on the impact of recrystallization defects on material strength as well as potential optimizations of material properties and manufacturing process. Therefore, it can be of great interest for materials research and development, production and quality control in industry. [source]

Damage analysis for structural integrity and durability of composite materials

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 7 2006
R. TALREJA
ABSTRACT Composite structures for mechanical and aerospace applications are designed to retain structural integrity and remain durable for the intended service life. Since the early 1970s important advances have been made in characterizing and modelling the underlying mechanical behaviour and developing tools and methodologies for predicting fracture and fatigue of composite materials. This paper presents a review of the concepts and analyses related to this area, and illustrates these by a few examples. The topics discussed are composite material strength in tension, compression and shear, damage and its progression in monotonic and cyclic loading, fatigue life prediction and damage induced changes in visco-elastic response. [source]

George W. Bush, Idealist

INTERNATIONAL AFFAIRS, Issue 3 2003
Michael J. Mazarr
There is much anger and confused grumbling these days outside the United States,and in Europe in particular,about the character of the Bush administration's foreign policy. Perceived American unilateralism is raising hackles and questions. This article contends that current trends in US foreign policy can be better understood by realizing that many senior Bush administration officials are not ,realists', at least as that philosophy of world politics is classically understood. Many of the resulting views,that, for example, threats to security often originate in ideology rather than material strength,are demonstrably correct and even hopeful in their faith in long-term historical trends. But there may be no getting around the essential contradictions required of US foreign policy in an age when America is the leading power, when a new global community of trading democracies is emerging, and yet when a number of distinctly old-style threats to the peace remain very much in evidence. Washington could do more to smooth the edges of those contradictions in order to point up the idealism and hopefulness of US policy. [source]

A new fabrication technique utilizing a composite material applied to orthopedic bracing

POLYMER COMPOSITES, Issue 1 2002
Bryan J. Morrison
An orthopedic brace fabrication and fitting technique was explored as a rapid and cost-effective alternative process to polypropylene fabrication. Other potential benefits could also be reduced weight and lower profile with the added advantage of allowing profile and firmness variation where desired. The novel process concept is based on the finding that a partially cured composite remains somewhat malleable. Clinicians conceivably can adjust an ankle-foot brace to the patient directly before fully curing the brace. Flexure experiments assessed both the partial curing concept and the ability to post-form. Results indicate that partial curing followed by ambient or heated adjustments and full curing compromises the strength by no more than 7%. However, adjustments resulted in a net displacement change averaging only 50% of that desired when heat was applied. It is also possible to post-form the fully cured brace. This compromises the material strength significantly in the deformed area, but it may be feasible for minor adjustments where applied loads are not extreme. This research demonstrates the feasibility of the process as an alternative to current techniques, especially for patients needing a strong brace. [source]

Instability investigation of cantilevered seacliffs

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 11 2008
Adam P. Young
Abstract Wave action is a fundamental mechanism in seacliff erosion, whereby wave undercutting creates an unstable cantilevered seacliff profile and can lead to large catastrophic cliff failures, thus threatening coastal infrastructure. This study investigated the instability of two such failures that occurred in Solana Beach, California, by combining terrestrial LIDAR scanning, cantilever beam theory and finite element analysis. Each landslide was detected by evaluating the surface change between subsequent high resolution digital terrain models derived from terrestrial LIDAR data. The dimensions of failed cantilever masses were determined using the surface change measurements and then incorporated into failure stress analysis. Superimposing stress distributions computed from elastic cantilever beam theory and finite element modeling provided a method to back-calculate the maximum developed tensile and shear stresses along each failure plane. The results of the stress superposition revealed that the bending stresses caused by the cantilevered load contributed the majority of stress leading to collapse. Both shear and tensile failure modes were investigated as potential cliff failure mechanisms by using a comparison of the back-calculated failure stresses to material strengths found in laboratory testing. Based on the results of this research, the tensile strength of the cliff material was exceeded at both locations, thus causing the cliffs to collapse in tension. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Workshop summary on physical and chemical properties of potential Earth impactors

METEORITICS & PLANETARY SCIENCE, Issue 12 2002
W. F. Huebner
The goal was to develop a roadmap for determining the physical and chemical properties of NEOs in the coming decades to meet the scientific requirements for development of Earth collision avoidance technology. We identified many properties that are desired, but four measurements are needed most critically for any potentially hazardous NEO: (1) its mass, (2) its mass distribution, (3) its material strengths, and (4) its internal structure. Global (whole-body) properties, such as material strengths and internal structure, can be determined best from the analyses of permeating waves: artificially initiated seismology and multifrequency reflection and transmission radio tomography. Seismology provides the best geophysical (material strengths) data of NEOs composed of consolidated materials while radio tomography provides the best geological data (e.g., the state of fracture) of electrically nonconducting media. Thus, the two methods are complementary: seismology is most suitable for stony and metallic asteroids, while radio tomography is most appropriate for comet nuclei and carbonaceous asteroids. The three main conclusions are (1) remote sensing for physical characterization should be increased, (2) several dedicated NEO missions should be prepared for geophysical and geological investigations, and (3) that it is prudent to develop and prove the technology to make geophysical measurements on NEOs now. [source]