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As a new intelligent material, Nano-Magnetorheological Material (Nano-MRM) gets a wide range of great concern to researchers and its application scope is very broad. For diagnosis and treatment cancer in one of the most difficult types of intracranial aneurysm, the work established the most practical model on Nano-MRM in intracranial aneurysm therapy research and analyzed quantitatively. The results are effective. Hope the work can be a strong impetus to human progress in the anti-cancer project.

A constitutive model is developed for shape memory alloys (SMAs) based on the concept that an SMA is a mixture composed of austenite and martensite. The deformation of the martensite is separated into elastic, thermal, reorientation and plastic parts, and that of the austenite is separated into elastic, thermal and plastic parts. The volume fraction of each phase is determined with the modified Tanaka’s transformation rule. The typical constitutive behavior of some SMAs, including pseudoelasticity, shape memory effect, plastic deformation as well as its effects, is analyzed.

The kind double-channel Magnetorheological Fluids (MRFs) testing equipment is characterized by low inertia of rotating element and ensures certain precision and economical applicability. Especially, research on and analyze the strain tensor by Finite element software Abaqus. Hope cordially the research can accelerate the study of MRFs with a rapid development.

Magnetorheological materials belong to a kind of new intelligent materials and their application prospect is very optimistic, however electromagnetic relations are very complex, and with the outside world and boundary conditions have close relations, so each model and theory has its pertinence and limitations, hard to get the universal unified the constitutive relations, so this paper based on energy, gets a set of magnetorheological materials about the theory.

An incremental form of constitutive model is proposed for shape memory alloys using the modified strain based on experimental results and the finite element analysis, taking into account of the laminar microstructure, the thickness of martensite phase lamina and the interaction between the two phases. The pseudoelastisity of NiTi shape memory alloy micro-tube subjected to pure tension and pure torsion are analyzed and compared with the experimental results respectively. It can be seen that the pseudoelastic behavior, especially the stress drop during tension processes, can be well described with the proposed model.

A two-phase constitutive model for shape memory alloys (SMAs) is proposed based on the fact that SMAs is dynamically composed of austenite and martensite. The behavior of SMAs is regarded as the dynamic combination of the individual behavior of each phase. This model can describe the main characteristics of SMAs, such as pseudoelasticity and shape memory effect. The corresponding numerical algorithm was also developed to describe the main features of shape memory alloy Au-47.5at.%Cd.

The microstructure and mechanical properties of magnetorheological (MR) fluids with mixed particles of different size are investigated. The interaction between particles of different radius is obtained and the model for motion of particles is proposed. Under an external magnetic field, the microstructure and yield shear stress of MR fluids with mixed particles of different sizes are simulated. It shows that particle size ratio in bidisperse suspensions can influence the performance of MR fluids.

Scanning electron microscope (SEM) observation was performed and showed that shank bone is a kind of bioceramic composite consisting of laminated hydroxyapatite and organic materials. The hydroxyapatite layers are parallel with the surface of the bone and consist of numerous thin and long hydroxyapatite sheet fibers. The hydroxyapatite sheet fibers in different hydroxyapatite make a little angle with each other and compose a kind of screwy microstructure. The maximum pullout force of the screwy microstructure was investigated and compared with that of parallel microstructure. It shows that the maximum pullout force of the screwy microstructure is markedly larger than that of the parallel microstructure, which was experimentally validated.

As a typical biological material, bone possesses high fracture strength and fracture toughness, which are closely related to its exquisite microstructure. SEM observation of a cannon bone shows that the bone is a kind of layered bioceramic composite consisting of hydroxyapatite sheets and collagen matrix. The hydroxyapatite sheets are of long and thin shape, distributing in parallel. The fracture toughness of the bone is analyzed with the representative model of the hydroxyapatite sheets and the concept of maximum pullout energy. It is shown that the lathy shape as well as the parallel distribution of the hydroxyapatite sheets increases the pullout energy and endows the bone with high fracture toughness.

Bone is a kind of biomaterial in nature. It behaves favorable strength, stiffness and fracture toughness which are closely related to its fine microstructures. Scanning electron microscope (SEM) observation on a shinbone shows that the bone is a kind of natural bioceramic composite consisting of hydroxyapatite layers and collagen matrix. The hydroxyapatite layers are arranged in a parallel distribution and consist of many hydroxyapatite sheets. The fracture toughness of the bone was analyzed based on the representative model of the microstructure in the bone and the idea of maximum pullout energy. The analytical result shows that the long and thin shape as well as the parallel distribution of the hydroxyapatite sheets increase the maximum pullout energy of the sheets and enhance the fracture toughness of the bone.

Scanning electron microscope (SEM) observation shows that Solid-trough shell is a kind of bioceramic composite consisting of laminated aragonite and organic materials. The aragonite layers are parallel with the surface of the shell and consist of numerous thin and long aragonite fibers. The aragonite fibers in an arbitrary aragonite layers possess different directions and compose a kind of screwy microstructure. The maximum pullout force of the screwy microstructure was investigated and compared with that of parallel microstructure based on their representative models. It shows that the maximum pullout force of the screwy microstructure is markedly larger than that of the parallel microstructure, which was experimentally validated.

Molluscan shell possesses excellent strength, stiffness and fracture toughness that are closely related to its exquisite microstructure. SEM observation of a clam’ shell showed that the shell is a kind of bioceramic composite consisting of aragonite and protein layers parallel with the surface of the shell. The observation also showed that the aragonite layers are composed of long and thin aragonite sheets. Many aragonite sheets are of curving shape at the center of the shell. The higher fracture toughness of the shell was analyzed based on the representative model of the curving aragonite sheets and the concept of the maximum pullout force that is related to the fracture toughness of the shell. The analytical result showed that the maximum pullout force of the curving aragonite sheet is larger than that of straight aragonite sheets, which may effectively enhance the fracture toughness of the shell.

The stress-strain behavior of cast magnesium alloy (AM60) was investigated by strain-controlled cyclic testing carried out on MTS. In order to describe the cyclic stress and strain properties of AM60 by means of the energy storing characteristics of microstructure during irreversible deformation, a plastic constitutive model with no yielding surface was developed for single crystal by adopting a spring-dashpot mechanical system. Plastic dashpots reflecting the material transient response were introduced to describe the plasticity of slip systems. By utilizing the KBW self-consistent theory, a polycrystalline plastic constitutive model for Magnesium alloy was formed. The numerical analysis in the corresponding algorithm is greatly simplified as no process of searching for the activation of the slip systems and slip directions is required. The cyclic stress-strain behavior, based on this model, is discussed. The simulation results show good agreement with the experimental data for AM60.

Casting magnesium alloys are heterogeneous materials containing numerous voids. Assuming the voids are spherical, in the present investigation, the evolution equations of the growth and nucleation of the voids have been presented. Combining the evolution equation of the void growth with that of the void nucleation, the evolution rule of the voids was obtained. Based on the void evolution rule a nonclassical elastoplastic constitutive model involving void evolution was developed. The corresponding numerical algorithm and finite element procedure were developed and applied to the analyses of the elastoplastic response and the porosity of casting magnesium alloy. The calculated results show the satisfactory agreement with experiments.

The SEM observation on a conch’s shell shows that the shell is a kind of laminated bioceramic composite composed of aragonite layers and organic matrix. Each aragonite layer is parallel with the surface of the shell and consists of many thin aragonite sheets. These aragonite sheets are perpendicular to the layer where they are located. The observation also shows that the orientations of the sheets in different layers are different and these aragonite sheets compose various layups. A kind of lambdoidal layup is found. The maximum pullout force of the lambdoidal layup is analyzed based on its representative model. The result shows that the lambdoidal layup can markedly increase the pullout force of the layup and improve the fracture toughness of the shell.

Molluscan shell is strong, stiff, tough and shows an erose fracture surface when it is broken. In this research, the SEM observation on a Rufescens’s shell shows that the shell consists of aragonite layers and collagen matrix. Each aragonite layer is parallel to the surface of the shell and consists of many thin aragonite sheets. These aragonite sheets are perpendicular to the layer where they are located. The observation also shows that the direction of the sheets in different layer is various and a kind of herringbone distribution is found. The maximum pullout force of the herringbone distribution is analyzed based on its representative model, and it shows that the herringbone distribution can markedly increase the pullout force of the distribution and improve the fracture toughness of the shell.

Most structural materials existing in nature take the form of composite. After centuries’ evolution and modification, these natural materials gain highly optimized structures and prominent performances. The SEM observation on the cuticle of Hydrophilidae shows that the cuticle is a biocomposite reinforced with chitin fibers. The chitin fibers are embedded in a protein matrix of the cuticle in the form of layers. A kind of revolving fiber layup was found. Observation also shows that there is a kind of special branched fiber consisting of a long fiber and many short fibers. The maximum pullout force of the branched fiber is analyzed. The results show that the maximum pullout force of the branched fiber is distinctly larger than that of ordinary straight fiber.

Most structural materials existing in nature take the form of composite. After centuries’ evolution, these materials gain highly optimized microstructures and performances. In this work, a kind of natural biomaterial, shinbone, is observed with a scanning electron microscope (SEM). The observation result shows that the bone is a bioceramic composite consisting of hydroxyapatite layers and collagen matrix. The observation also shows that the hydroxyapatite layers are composed of hydroxyapatite sheets. The hydroxyapatite sheets are of thin and long shape and parallel distribution along the orientation of the maximum main stress of the bone. The shape and distribution of the hydroxyapatite sheets may endow the bone with favorable fracture toughness, which is analyzed and illuminated based a representational model of the hydroxyapatite sheets and the idea of maximum pullout force.

Bone is a kind of biomaterial in nature. It behaves favorable strength, stiffness and fracture toughness which are closely related to its fine microstructure. SEM observation on a shankbone shows that the bone is a kind of natural bioceramic composite consisted of hydroxyapatite layers and collagen matrix. The observation also shows that the hydroxyapatite layers consist of many hydroxyapatite sheets and are arranged in a parallel distribution. The fracture toughness of the bone is analyzed based on the representative model of the microstructure of the bone and the idea of maximum pullout force. The analytical result shows that the long and thin shape as well as the parallel distribution of the hydroxyapatite sheets improves the maximum pullout force of the sheets and the fracture toughness of the bone.

The microstructure of a Fragum unedo shell is observed with a scanning electronic microscope (SEM). It shows that the shell is a kind of bio-ceramic composite consisting of aragonite and collagen protein layers. The observation also shows that the aragonite layers consist of thin and long aragonite sheets. A kind of particular herringbone structure of the aragonite sheets is found. In the structure, the aragonite sheets in an arbitrary aragonite layer make a crossed angle against that in its neighboring aragonite layers. Based on the SEM observation the comparative experiments in the maximum pull-out forces of both the herringbone and conventional 0°-structures are conducted. It shows that the maximum pull-out force of the herringbone structure is markedly larger than that of the 0°-structure, and the larger the crossed angle is, the more the maximum pull-out force of the herringbone structure will increase compared with that of the 0°-structure.

In this paper, the microstructure of chafer cuticle is observed with a scanning electron microscope (SEM). The observation shows that the insect cuticle is a kind of biocomposite with hybrid structural characteristic of various chitin fibers embedded in protein matrix. The reinforced chitin fibers vary in size, shape, property and distribution, which are related to their location in the cuticle. Near the surface of the cuticle, the chitin fibers are smaller, stiffer, more circular, and the orientations of the chitin-fiber plies are various. A kind of helicoidal layup is found. The dependence of fracture strength on the fiber diameter and the dependence of fracture toughness on the parameters related to helicoidal layup are experimentally investigated. It shows that the smaller fiber and the helicoidal layup endow the surface of the cuticle with higher fracture strength and toughness.

Insect cuticle possesses excellent mechanical properties, such as strength, stiffness and fracture toughness, which are closely related to its elaborate microstructures optimized through centuries’ evolution. SEM observation on Hydrophilidae cuticle shows a kind of biocomposite consisting of chitin-fiber plies and protein matrix, and the chitin-fiber plies are composed of several special arrangements. The observation also shows that there are many holes in the cuticle and the fibers passing along the brims of the holes round the holes continuously. Making use of such microstructure, a kind of biomimetic composite laminate with round-hole-fiber distribution is fabricated with preformed-hole method. The ultimate strength of the composite laminate is investigated and compared with that of the composite laminate with a hole drilled. It shows that the ultimate strength of the former is distinctly higher than that of the latter.

Molluscan shell is a typical biocomposite in nature. It possesses excellent strength, stiffness and fracture toughness, which are closely related to its exquisite microstructure. SEM observation on clam’ shell shows that the shell is a kind of layered ceramic composite consisting of aragonite sheets and protein matrix. The aragonite sheets have long and thin shape and are arranged in a parallel manner. The higher fracture toughness of the shell is analyzed based on its representative model and the concept of maximal pullout energy. Analysis shows that the long and thin shape as well as the parallel arrangement of these sheets will substantially improve the maximal pullout energy of the sheets and the fracture toughness of the shell.

Molluscan shell is strong, stiff, tough and shows a erose fracture surface when it is broken. In this paper, the SEM observation on a clam's shell shows that the shell is composed of aragonite layers and organic matrix. Each aragonite layer is parallel to the surface of the shell and consists of many thin aragonite sheets. These aragonite sheets are perpendicular to the layer where they are located. The observation also shows that the direction of the sheets in different layer is various and a kind of herringbone arrangement is found. The maximum pullout force of the herringbone arrangement is analyzed based on its representative model, and it shows that the herringbone arrangement can markedly increase the pullout force of the arrangement and improve the fracture toughness of the shell.