Journal of The Society of Materials Science, Japan 

About: Journal of The Society of Materials Science, Japan is an academic journal. The journal publishes majorly in the area(s): Fatigue limit & Crack closure. Over the lifetime, 5634 publications have been published receiving 18681 citations.

Composite Materials (I)

Abstract: M ost biological materials are constructed from simple building blocks, yet they exhibit extraordinary properties. High-performance organic protein materials such as silk or collagen, for example, are usually composed of only a few distinct amino acids, but they combine to form structures that display a very wide range of material properties and perform many different biological functions 1–5. And the addition of other types of building blocks leads to even better performance: for example, bone is strong and tough because the collagen matrix also contains hydroxyapatite mineral platelets. What's intriguing is that the macroscopic properties of the final material are much more than the sum of the parts, and that these properties can change in response to the demands being placed on them (a property referred to as tunability) 2–5. These exciting features are known to derive from the peculiar structural make-up of natural materials, which contain geometric details over a vast range of length scales, merging the common concepts of 'structure' and 'material'. Today it is possible to routinely synthesize nanoscale building blocks with many excellent material properties, such as carbon nanotubes or graphene sheets, but there has been relatively little progress in exploiting these properties in large-scale materials and devices. We lack the ability to map the excellent properties of these tiny material building blocks towards larger scales, where the performance of resulting materials doesn't live up to our expectations. It seems natural, therefore, to look to nature for inspiration when seeking to make new materials that can harness the potential of these synthetic building blocks 4,6. Indeed, by starting with building blocks that are superior to those used by nature, it should be possible to develop new materials with properties that greatly surpass the natural ones. In addition to enhanced strength, for example, such a material could display an exquisite responsiveness to external cues, which could be used to tune its properties on demand or be exploited in sensing applications. Mezzenga of ETH Zürich report that they have combined graphene sheets with amyloid protein fibrils to create a nanocomposite with useful chemical, mechanical and sensing properties 7 (Fig. 1). Mezzenga and co-workers emulate the molecular structure of bone, with graphene sheets replacing the rigid hydroxyapatite mineral platelets found in bone, and amyloid protein fibrils replacing the softer collagen protein fibres. They start by simply combining amyloid protein fibrils and sheets of graphene oxide in water. The amyloid …

Experimental reconfirmation of characteristic S-N property for high carbon chromium bearing steel in wide life region in rotating bending

Abstract: In fatigue tests of high strength steels and surface hardened steels, a characteristic fatigue behavior such that S-N curve tends to come down again in the long life region of N>107 was often observed and reported by many researchers. When the mechanical design is based on the fatigue limit of the material, the above aspect introduces a typical difficulty to provide the reliability of the mechanical structures. In order to clarify such S-N characteristics in wide life region, a series of fatigue tests were performed by means of same type fatigue testing machines and same type of fatigue specimens in a definite high carbon chromium steel for the use of bearing as a collaborative study by the authors. Thus the complicated S-N property of this steel was tentatively interpreted as duplex S-N characteristics given by superposition of S-N curves for the respective fracture modes of the surface-originated fracture and the inclusion-originated fish-eye fracture.

Recent progress in constitutive modeling for ratchetting

Abstract: Classical constitutive models of cyclic plasticity are very poor in predicting the progressive deformation of ratchetting, though ratchetting is an important factor in the design of structural components. Recent works done in the last decade, however, have enabled us to simulate the strain accumulation due to ratchetting with reasonable accuracy. In the present paper, first, the state of the art in constitutive modeling for ratchetting is described by criticizing the classical models and by reviewing the recent modifications introduced for ratchetting. Then, the application of recent and calssical models to ratcheting problems such as the thermal ratchetting induced by moving temperature distribution is discussed to show the effectiveness of recent models in simulating ratchetting.