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In this paper, effects of initial micro-structures on deformation behaviors of commercial pure titanium were elaborated by investigating the evolution of dislocation boundary and its adiabatic shear sensitivity. At the low to medium stain rates, the main plastic deformation mechanism of as-annealed commercial pure titanium is dislocation slipping. Meanwhile, geometrically necessary boundaries (GNBs) with different directions are generated and crossed with each other. However, new dislocation boundaries are formed in as-cold rolled plates, which are parallel to the initial ones induced by cold rolling. When the strain rate is up to 1000 s-1, the initial dislocation boundary playes an adverse role in the adiabatic shear sensitivity of commercial pure titanium. The adiabatic shear band is the high-speed deformation characteristic micro-structure in commercial pure titanium. In addition, dynamic recrystallized grains are generated in the center of an adiabatic shear band, which is consistent with the sub-grain rotation mechanism.

The contribution is focused on estimating the shear modulus of the samples of circular and hollow circular sections by static method. The samples were loaded by simple torsion, individual sections were stressed by shear stress. Theoretical basis are determined by linear elasticity and strength theory and they define the relation between shear modulus, maximum shear stress and relative strains. Relative strains are determined by using measurement apparatus and measurement system Quantum X MX 840.

Different geometries of shear test specimens were experimentally and numerically investigated. They are used for calibration of a virtual model, to be used for sheet metal blanking. Different specimen configurations were simulated in order to determine the strain and stress fields and the potential of producing pure shear failure. Tensile and shear tests were performed using DC01 steel material. The experimental data are used later to calibrate a material with Johnson-Cook elastic-plastic model.

Effects of the compressive rate, specimen dimension, specimen orientation and microstructure on the compressive property at ambient temperature of extruded ZK60-xDy alloy rods were investigated. The results show that the specimen dimension, specimen orientation and microstructure except the compressive rate play a significant role on the compressive property. The compressive strength σbc increased significantly by the improving amplitude of 65~110 MPa with increasing the height/diameter ratio h/φ of the cylindrical compressive specimen from 0.5 to 1, however it was not enhanced further as h/φ increased to 2. With increasing the value of h/φ, the yield stage on the compressive curve was strengthened gradually, and meanwhile the compressive macro-fracture changed from the inverted "V" type to pure shear fracture with an angle of 45°. Compared with the specimen whose axial direction was parallel to the transverse direction, σbc was enhanced by the improving amplitude of 60~120 MPa for the specimen whose axial direction was parallel to the extrusion direction. When small amount of Dy (0.31%) was added into ZK60 alloy, σbc was increased from 500 MPa to 540 MPa. However, it slightly decreased to 515 MPa again when the Dy content increased to 4.32%.

There have been many efforts to investigate and develop a numerical damage and failure models during metal forming process of lightweight alloys. Due to the difficulties experienced during experimental determination of the incurred damage during forming of lightweight alloys, many researchers have sought to predict the damage, failure and forming limit curves using numerical simulations. Conventional finite element analysis of metal forming processes for lightweight parts which have been subjected to a nonlinear strain history often breaks down due to numerical difficulties. Many scientific research works have attempted to use different mathematical methods to model the damage progression and failure of alloying material under large deformation. The damage initiation, progression and also failure of alloys are a result of accumulated damage under plastic deformation [1-3]. These models (single and multi-damage parameters) are generally based on energy and constitutive equations to simulate the fracture and failure processes in metal alloys. However, these methods have serious short comes in predicting the damage and failure in metal forming process with strain rate effects. In the present study, following the in-depth study of damage initiation and progression in lightweight alloys, a frame work has been setup to develop a numerical model for damage accumulation during forming process. Based on the existing damage theory, a mathematical extension for damage initiation and also damage accumulation under wide range of stress triaxiality (including near pure shear) has been developed. An experimental program has also been carried out using samples made from lightweight alloys. One of the main contributions of this paper is to show the advantages of using plasticity-based modified damage models to investigate the damage accumulation in cast aluminium alloys.

Fibre-concrete is rapidly developing material, which becomes more widely often used. Strong feature of fibre-concrete is its ability of carrying stress after reaching the ultimate strength. In order to fully understand this material it is necessary to observe its performance in different types of failure. The aim was to create experiment in which the conditions of pure torsion are realized without accompanying by other stress. During testing there will be observed not only the ultimate strength, but also the torque-twist diagram and stress variation on the descending post-peak curve. Experiment of this new character will give results of great importance and will contribute to full understanding of performance of material fibre-concrete.

Experimental and numerical investigations were conducted to characterize the joint strength and failure modes in adhesively bonded double lap shear type specimens. As bonded joints are more efficient when designed for pure shear, the used specimens consisted of double lap joints to be used for moderately thick to thick foam core sandwich components. The foam thickness and overlap length are parameters investigated hereby. For such an experimental testing setup, in which peeling is reduced considerably, we combined finite element (FE) simulations and digital image correlation (DIC) for obtaining a more complete insight on the peeling and shear strain distribution in the foam, at the interface with the adherend and in the whole overlap region.

This paper describes an experimental study on the pure shear properties of E-Glass woven fabric by picture frame test. During shear deformation, the fabric yarns experience large angular change between warp and weft yarns. The picture frame test is one of the fundamental methods to characterize the in-plane shear behaviour of woven fabrics and can produce a quite uniform shear deformation state in the fabric sheet. Tests are conducted on two different size of EGlass specimens 40x40 mm and 80x80 mm. For a double increase the specimen size, the values of shear force and axial load are also almost double increase at the maximum displacement and shear angle.

A dedicated blanking test (DBT) was designed to measure the bonding shear strength of a metallic hybrid sample. To identify the required design parameters of the rig, a macro numerical model was developed using Abaqus Finite element (FE) package. Copper clad aluminum hybrid samples fabricated by an axi symmetric forward spiral composite extrusion (AFSCE) process were analyzed using the developed numerical model. The effect of the design parameters including sample thickness, blanking clearance and the die and punch fillet radii were determined to ensure a pure shear blanking along the interface. The numerical results showed that the sample thickness, clearance and fillet radii have a significant effect on the measured bond shear strength and the location of the failure. The required rig was designed and composite copper clad aluminum bonding shear strength was experimentally determined based on the numerical findings.

This paper is concerned with the prediction of fracture strains for DP980 steel sheets using a modified Lou–Huh ductile fracture criterion. The usage of DP980 steel is significantly increasing in the automotive industry for weight reduction, enhancement of crashworthiness and safety of car body. The material behavior of AHSS show unpredictable and sudden fracture during sheet metal forming process. A modified Lou–Huh ductile fracture criterion is utilized to predict the formability of AHSS because the conventional FLD constructed based on necking is unable to evaluate the formability of AHSS. Fracture loci were extracted from 3D fracture envelopes by assuming the plane stress condition to evaluate equivalent plastic strain up to the point of fracture at a wide range of loading paths. Three different types of specimens such as pure shear, dog-bone and plane strain grooved specimens were used for tensile tests to construct 3D fracture envelopes of DP980. Fracture strain of each loading path was evaluated to show that there is little deviation between predicted fracture strains and experimentally acquired ones. From the comparison, it is concluded that the 3D fracture envelopes can accurately predict the onset of the fracture of DP980 steel sheets in complicated loading conditions including the pure shear condition.

There have been many efforts to investigate and develop a mechanical plasticity, damage and failure models for metal alloys in the last couple of decades. These models (single and multi-damage parameters) are generally based on energy and constitutive equations to simulate the fracture and failure processes in metal alloys. The conventional fracture mechanics theory and its applications have been successfully employed to study fracture and failure processes. However, these methods have serious short comes in predicting the damage and failure in metal alloys where the fracture is dominated by the presence of defects like micro-voids (and their growth, nucleation and coalescence), oxides and inclusions. In the present study, following the in-depth study of damage initiation and progression in aluminium alloys, a frame work has been setup to develop a numerical model for damage accumulation. Based on the existing phenomenological damage theory, a mathematical basis for damage initiation and also damage accumulation under wide range of stress triaxiality (including near pure shear) has been developed. The damage model has been checked and verified using a result of experimental-simulation comparative study. The experiments have been carried out using samples made from squeezed and high pressure casting step plates. One of the main contributions of this paper is to show the advantages of using plasticity-based modified damage models to investigate the damage accumulation in cast aluminium alloys.

The adiabatic shear bands (ASB) of the thick-walled cylinder have been studied by many researchers in the recent years. The onset and evolutions of the multiple shear failure of metal cylinder under explosive loadings are affected by many factors such as the characteristics of the impulsive loadings, the dynamic behavior of the materials, etc. In this work, a tube compression driven by electro-magnetic forces is introduced, which enables to carry out the experiments of the spontaneous evolution of multiple adiabatic shear bands in metal tube. The FEM simulation was conducted to investigate the evolution process of strain localization with coupled thermo-mechanical analysis. The FEM results show that ASB initiates when the stress drops rapidly and strain growth and not when it reaches the maximum shear stress. Once the shear band is formed, elastic unloading occurs beside the shear band. The different behaviors of the damage introduced in the strain softening model affect the initial nucleation strain and the distribution of ASBs. With the increase of material damage softening, the initial strain of shear band decreases and the number of shear bands increases.

Damage modeling approach is increasingly used to simulate fracture and debonding processes in adhesively bonded joint. In order to understand the relation between the delamination behavior of different types of adhesives and the type of cohesive zone models (CZMs), the pure tension and pure shear experiments were conducted used two distinct adhesives, an epoxy-based adhesive in a brittle manner and VHBTM tape adhesive in a ductile manner. The traction-separation relations of the two adhesives were extracted from the tension and shear experimental results. Three types of cohesive zone models (CZMs) are adopted, including the exponential, bilinear, and trapezoidal models. VUMAT subroutine of CZMs as the adhesive layer is used to simulate the specimen tension and shear debonding procedures. The results demonstrate that (i) the bilinear CZM more suitably describes the brittle adhesive and the exponential CZM suitably describes the ductile adhesive to simulate the tension and shear failure. (ii) cohesive strength and work of separation are the significant affections on the simulation results. and (iii) the shape of CZM is a significant affections on the simulation the pure tension and shear debonding procedure.

Through scanning electron microscope (SEM) observation on kinetic friction and static friction deformation, our data show that granular nanoparticles (commonly 60-80nm with diameter, d) are widespreadly distributions in narrow friction zones. Furthermore, the identification markings, such as nature, experiment and fabric orientation etc., usefully deal with the mechanical analysis,and the granular nanoparticle distributions in narrow friction zones could be subdivided into three kinds, i.e. simple shear, pure shear and rotational shear pattern. Additionally, note that under stress action physico-chemical phase changes might be respectively caused by internal cohesion and dynamic differentiation in the narrow friction zones. These analyses deduce that some few complex idea fields, including structural stress, physics and chemistry field, with spatial and temporal evolution exist in the narrow friction zones, moreover, they viably regulate the nanoparticle distribution.

The mechanical properties of low-yield-point (LYP) steel and its advantages as seismic steel are introduced in this paper. The theoretical equations of inelastic shear buckling stress at the pure shear action for the LYP steel are derived from unified theory of plastic buckling. The relationship curve of inelastic shear buckling strength and width-thickness ratio of LYP steel shear wall at the different height-width ratios of plate is given through iteration calculation process. The effectiveness of theoretical equations used for calculating the buckling stress is verified by experimental results.

The impact shear response of crystallized polypropylene under combined compression and shear loading was studied by using an inclined gas gun and electro-magnetic particle velocity gauges. The experimental results show that the transverse wave velocity increases nonlinearly with the impact velocity, indicating its shear behavior is strongly related to the hydrostatic pressure. Remarkable shear wave attenuation occurs near the impact surface when the impact velocity and inclination angle reach the critical value. The micro-observation of recovered samples with a polarized optical microscope reveals that there exists a melting layer of about 2-3μm thick, i.e. adiabatic shear failure layer, very near the impact surface (about 5μm) which causes the shear wave attenuation.

The Nanpu Sag, located in the north part of Huanghua Depression of Bohai Bay Basin, is a Cenozoic petroliferous extensional sag, the shallow oil reservoirs have great exploration potential. Former exploration suggested that there is complex relationship between Late cenozoic faults and hydrocarbon accumulation, but there is no detailed discussion. Based on the structural interpretation of 3D seismic data, the Late Cenozoic fault characters including typical fault configuration in profile and fault arrays in plane are analyzed, furthermore, the formation mechanism of the faults is discussed. It is concluded that late Cenozoic faults were formed by extension other than strike-slip movement, which was controlled by the mechanism of pure shear in the lower crust during the period. In addition, the relationship between Late Cenozoic faults and shallow hydrocarbon accumulation is discussed, it indicates that the faults controlled the formation of shallow closures and constituted the effective hydrocarbon pathways connecting deep source rock and shallow traps.

The shear failure modes of anisotropic solids are studied here based on the elastic standard space of physical presentation, some new shear failure phenomena for anisotropic solids are presented. The relations between shear failure modes and anisotropy are discussed. The results show that there are obvious differences in shear failure modes for different anisotropic solids.

The process of bonding degradation throughout the whole loading phase up to the total collapse has been investigated by models of interlaminar degradation in composite materials and subsequently adapted to the problem of structural bonding. The physical phenomenon represented by these models is exactly the same that must be studied in the case of metal plates adhered with geopolymers: the adhesion between substrates. In this work, it was investigated the adherence of joint steel plates through propagation tests of clefts in mixed mode MMF (Mixed-Mode Flexure Test) which combine the efforts of traction (due to differential thermal expansion) and shear (due the slipping and preassure due the own weight of the adhered layers), in other words, modes I (pure opening) and II (pure shear) of propagation, being one of the most common glued plates. It was used two types of geopolymeric adhesives (one made of metakaolinite and another with weathered soil) activated with sodium silicate. The bonded systems were subjected to temperatures between 55°C and 600°C in order to evaluate its potential against the use of epoxy-based adhesives. The substrates used were steel. In general, the adhesives made of metakaolinite had better adhesion.

Based on the analysis characteristics of orthotropic composite material under antisymmetric force, a new measurement method is established which can independently measure the fringe value of optical shear orthotropic material by pure-shear experiment. Two orthotropic photo-elastic composite material beams with rectangular cross-section which fiber orientation is 0 °, 90 ° respectively are loaded anti-symmetric force, so that the anti-symmetric section is in a pure shear stress state. The fringe value of orthotropic photo-elastic shear composite material is measured . The results agree with three stripe specimens tensile experiment.

Through a series of tests on saturated remoulded clay, initial shear stress on dynamic shear modulus and damping ratio under the condition of large strain(>10-3) is examined. The test data indicate that initial shear stress effects on stress-strain relation and dynamic modulus and damping ratio are obvious. With the initial shear stress increasing, the characteristic of the stress-strain relation changes from cyclic deformation to accumulative deformation, and there is difference in variation pattern of dynamic shear modulus and damping ratio with cyclic number increasing.

How to design the interfacial properties is a significant fundamental issue in the field of the composite materials, while little work was concerned with the mechanical design of the interface for the fiber reinforced polymer. In the present work, a fiber bundle embedded in the matrix was described as a transversely isotropic material. Based on the imperfect interface conditions, the interface parameters were derived to satisfy the neutral conditions for the composite materials reinforced by the elliptical cross-section fiber bundle. It is found that the interface parameter is not always associated with the applied loading in the case of the anti-plane shear. In the state of equal-biaxial tension, the normal interface parameter is merely related to the mechanical properties of components except for the shape of the fiber bundle, but independent of the loading magnitude. In the other cases of pure shear and uniaxial tension, the neutral interface does not exist except that the fiber bundle has a circular cross-section. It is also found that the interface parameters can be expressed in the forms similar to that for an isotropic inclusion by using Kolosov constant in the in-plane deformations.

The behavior of interfaces between coarse-grained soil and gravel-clay introduced by earthquake plays an important role in analyzing the stability of the impermeable structure in rock filling dams. Using the NGI-type simple shear apparatus, cyclic simple shear tests were performed to study the mechanical behaviors of the interface; shear deformations both along the interface and in the coarse-grained soil were analyzed. The test results indicate that: the cyclic shear strength of the interface was found approximately linearly proportional to the normal stress applied on the interface; meanwhile, the shear deformations reached their peak values in the first cycle, respectively; and the direction of initial shear stress significantly influenced the mode of relative displacement along the interface. In addition, shear shrinkage and shear dilation occurred alternately in each cycle. It also revealed that shear strength of the interface increases as the shear cycle increased and is approximately linear proportional to the normal stress level on the interface.

In order to analyze the microscopic shear mechanics behavior of sands, a numerical simulation is carried out in sand direct shear test with commercial DEM software PFC2D. By compiling FISH function, PFC2D is able to visualize principal stresses and their inclination inside the sample. In the simulation, particle rotation gradient and particle displacement vector are observed to analyze the microscopic formation mechanism of shear band. The strain and deformation is concentrated in a band whose thickness is about 10 times of average particle diameter and the band is close to the shear plane. The porosity ratio in shear band is higher than other parts of the sample with shear process.

In this paper, the shear force in the shearing process of the drum type linear blade flying shear is done. Two different approaches were taken to establish the shear force formula, and then the finite element simulation. The comparison results of the calculated values and simulated values can be seen that as the thickness increases, the maximum shear force calculated by the pure shear force formula increases rapidly, the shear force calculated by the energy release rate formula is relatively small, and the finite element simulation values and calculated values close to each other when the plate thickness is small. The derived formula in this paper not only can be applied to complex engineering problems, but also has provided a theoretical basis for drum type linear blade flying shears on the shear force calculations and equipment design.

International audience; The optimization of automotive security components requires good knowledge of the material state after fabrication, particularly with respect to damage that may have been done to the material by the manufacturing process. To achieve this, numerical simulation of the fabrication process is often undertaken. However, classical continuum damage models, like the Gurson [3] model, are not appropriate for the simulation of the blanking by punching operation because the material damage is primarily the result of shear stresses. This work is focused on the use and validation of a modified Gurson type damage model capable of modeling this process, which has recently been proposed by Nahshan [7]. After a brief description of the modification, the implementation and the validation of the modified Gurson model is detailed. A comparison between the original Gurson model and the modified model is presented in order to highlight the importance of the modification for a pure shear stress state and to show that the two models are equivalent for a purely hydrostatic stress state. It is also shown that the results from the modified model are dependent on the finite element mesh size.

The characteristics and causes of the formation of adiabatic shear bands (ASB) in 30CrMnMo armor steel plate are analyzed by shooting 93W projectiles. The results show that adiabatic shear bands do not occur in the initial stages of the opening-crater and plugging. Adiabatic shear bands distributed sparsely appear in the stable penetrating phase because of the necessary strain volume. Adiabatic shear bands are formed along main shear stress lines at an angle of about 450 in relation to the penetrating direction. These are approximately consistent with the direction of the plastic deformation slip line. The non-homogenous deformation and centralizing of stress and strain inside the adiabatic shear band causes micro-cracks and micro-bores during cooling of the plate.

As it is well-known, TRIP 800 steels modify their structure with the deformation grade. So, part of the retained austenite turns into martensite by plastic deformation. The usual techniques tried out to evaluate this transformation whether do not lead to obtain good results or the experimentation with them is very complex. In this work, a magnetic induction method is experimented and developed in order to determine the evolution of a TRIP 800 steel microstructure with the strain grade. The variables that can have influence on this kind of analysis methodology have been studied and their effects evaluated. This method has been applied to determine the induced martensite by deformation under conditions of pure shear deformation. Results point that this method allows to state that the microstructure evolution taking place in TRIP 800 steels is not proportional to the strain applied.

In the present study, in situ measurements of applied torque and compressive load were conducted during high-pressure torsion (HPT) on Ti-23%Nb-0.7%Ta-2.0%Zr-1.2%O (in at %) , Gum Metal, by using four active strain-gage method. The shear stress was then calculated from the measured torque. The in situ measurements revealed that the maximum shear stress reaches ~2 GPa during HPT. This value is comparable to the ideal shear strength of Gum Metal, which was reported as ~1.8 GPa from experiments using single crystals. The deformation mechanism strongly depends on body-centered cubic (bcc) phase stability at an early stage of HPT straining, where the shear stress is well below the ideal shear strength. On the other hand, the deformation mechanism may be insensitive to the bcc phase stability at a later stage of HPT straining, where plastic deformation occurs at a strength close to the ideal shear strength.

The material modeling of hyper-elastic properties in rubber is generally characterized by the strain energy function. The strain energy functions have been represented either in term of the strain in variants that are functions of the stretch ratios, or directly in terms of the principal stretch. Successful modeling and design of rubber components relies on both the selection of an appropriate strain energy function and an accurate determination of material constants in the function. Material constants in the strain energy functions can be determined from the curve fitting of experimental stress-strain data. The uniaxial tension, equi-biaxial tension and pure shear test were performed to acquire the constants of the strain energy functions which were Mooney-Rivlin and Ogden model. Nonlinear finite element analysis was executed to evaluate the behavior of deformation and strain distribute by using the commercial finite element code. Also, the fatigue tests were carried out to obtain the fatigue failure. Fatigue failure was initiated at the critical location was observed during the fatigue test of rubber component, which was the same result predicted by the finite element analysis.

In this work, the static response of a perforated functionally graded plate is investigated under pure shear. Young’s modulus is assumed to vary arbitrarily along the radial direction, while Poisson’s ratio keeps constant. Using the stress function method, the governing equation is obtained, and then the series solution of stresses is derived with the aid of the Frobenius method. Numerical examples show that the convergence rate of the presented solution is rapid.

Studying the RC beams’ behavior, when they are exposed to combined shear and torsion is one of the most important problems in civil engineering which has been going on for half a century. In this study, to build a suitable set up and to load the beams properly, is of special importance when an area of little bending as the test area is needed in the pure shear and torsion test. In this investigation, based on the primary principle of structure analysis and fixed support, a setup is developed and its efficiency has been evaluated. Also this support system has been tested for five RC beams under the eccentricity of zero (pure shear) to extreme (pure torsion) and its efficiency has been evaluated and confirmed through these five tests.

The mechanics properties and fracture behaviors of 6061 aluminum alloy were investigated by the tensile shear tests and in-situ tensile shear tests with tensile shear specimen devised. The results indicate that a lot of slip bands parallel to tensile direction are produced on specimens’ surfaces. With shear strain rates increasing, the shear yield stress and shear ultimate stress of 6061 aluminum alloy remain constant basically, but the shear fracture strain decreased obviously. The grain boundaries of 6061 aluminum alloy are the weakest area and microcracks initiate at the grain boundaries parallel to tensile direction under shear stress. With shear stress increasing, the microcracks extend and coalesce. The fracture of specimens is due to coalescence or shearing between the microcracks.

Shear fracture (mode II) may be observed in concrete structures when subjected to confined or impact loading. Among the different techniques developed to investigate the shear strength of geomaterials, figures the Punch-Through Shear test (PTS test). It consists of a short cylinder with two cylindrical notches made on the lower and upper surfaces. Shear fracture is produced in the ligament due to the displacement of the central zone beside the peripheral zone. An experimental setup has been developed in LEM3 laboratory to measure the shear strength of concrete under quasi-static and dynamic loading. A high-speed hydraulic press allowed reaching strain-rates up to few per second. Steel and aluminium alloy confining rings have been used to induce a confining pressure in the fractured zone. Furthermore, radial notches have been performed in the specimen in order to deduce the radial stress at the ligament surface from the contact pressure between the confining ring and the outer surface of the specimen. The experimental results have been used to discuss the influence of free water and strain-rate on the shear behaviour of concrete.

According to the research status of construction spatial effects in large-long-deep foundation pit: mainly focus on numerical simulation, but theoretical research is not too many by now, a simplified method for calculating the construction spatial effects of large-long-deep foundation pit in cohesive soil was advanced. The soil layers around deep foundation pit were equal to cohesion-less isotropic soil mass by introducing the concept of equivalent internal friction angle. And then, by means of limit equilibrium analysis method combined with soil plasticity upper bound theory and associated flow rule, the spatial effects of two 3D failure modes: tension crack-shear and pure shear in deep foundation pit was studied concretely, and the corresponding formulas of spatial effects coefficient were put forward, also two examples were analyzed. The research results indicates that the method, which can complete by hand-calculation, avoids the defects of low efficiency, high cost and long period in numerical simulation, and the distribution characteristics and value size of spatial effects coefficient could be obtained directly from its calculation results, which can be used as guidance for the supporting structure, construction scheme design and the test points or sections choice in process of information monitoring.

In the paper the theory of cutting wood fiber on micron-level has been put forward, that is the cutting power of micron flake wood fiber is much smaller than the mechanical power consumed by grinding. Therefore, the manufacture method for micron flake wood fiber is a kind of way of materials preparation, which can economize energy, decrease in consumption and pollution. From the theoretical analysis, only a reasonable cutting-arrangement on direction can significantly reduce the power. So in the condition of reducing power, relying on pure shear to fracture fibers in tissue is the best effort, at the same time through the vertical ultra-high-speed cutting in grain, the micron filament fibers will be cut out. The influences produced by various factors for the formation of flake fibers have been verified through testing, including the improved tool material, the wood grain, the cutting speed and the improvements for locating specimen.Through the improved method for sluggish wood-fiber cutting, not only does this method reduce power consumption, but also decrease the probability of fiber cut off and substantial increase fiber’s length and quality. Moreover, after these flake fibers having been rescheduled, the elastic modulus of fiber MHFB hot pressed out can reach 5171Mpa, and the grip force of that can reach 1933N.

A hypothesis for two-stage character of deformation under load via the simple shear scheme is suggested. At the first stage in the shear strain range , where - the strain parameter, the metal microstructure changes in the way similar to that during elongation. At the second stage at accidental multi-scale rotative motions, similar to turbulent motions in liquids, take place in the metal. This stage of deformation is the proper simple shear. The results of experiments are presented, which testify in favor of the suggested hypothesis.

Square steel tube filled with steel reinforced concrete subjected to shear force was simulated by finite element method. Limit value of broken on pure shear, bending-shear and bending were given. Influence of stirrup ratio, steel reinforced ratio, strength of concrete under shear force was also analyzed. Finally, formula for pure shear capacity of square steel tube filled with steel reinforced concrete was proposed by research the calculated results. Calculated results showed that it agreed well with that of corresponding document.

Traditionally, applications of fracture mechanics have been mainly focused on cracks growing under the opening or mode I mechanism (three point bend specimen, middle tension specimen, crack tension specimen, etc.). When investigating instability under mixed mode loading conditions, three different alternatives can be envisaged consisting of: a) machining a hole in standard specimens, b) creating a crack oriented under a given angle, and c) using non-standard Arcan-Richard specimens. In this work, finite element calculations are performed to analyze the initial values of the fracture parameters in Arcan-Richard specimens. First, the influence of the normal stress mode to the shear stress mode ratio is analyzed, then the effect of the constraint level is discussed, and finally, the initial propagation angle of the daughter crack is derived.

A special fixture, which can control the ratio(λ) of normal stress/shear stress, was used to study the effect of normal stress on the shear banding behaviors in a Zr-based bulk metallic glasses in the present paper. The experimental results demonstrated that the plastic displacement increased with increasing of λ. Observations of shear bands pattern on the sample surfaces indicated that normal stress have significant impact on the inclined angle, numerical density and length of shear bands. In addition, normal stress is the major factor of inducing multiple shear bands with intersecting, branching and slipping. Based on the observations, the mechanism of plasticity enhancement due to the increasing of normal stress was explored.

In this work there has been conducted theoretical analysis of the process of asymmetric rolling of plate in finishers of plate mills. On the basis of the carried out research the influence of asymmetry factor av, deformation ε and strip form h0/D on strip bend during the process of rolling has been determined. For this reason, the following resolutions have been pointed out: velocity of flow, pure shear and intensity of deformation in deformation zone.

A numerical analysis by means of the ANSYS code was performed in order to identify the ratio of both stress intensity factors and crack tip opening displacements for a cylindrical specimen with circumferential V-notch loaded by remote pure shear stress. This kind of loading produces pure mode II and III loading in four points on the circumferential crack front while the mix mode II+III exists in all other crack front points. In the linear-elastic range, the ratio of maximum values of mode III and mode II stress intensity factors was found to be . On the other hand, the ratio of crack tip opening displacements in the elastoplastic range approaches . These results can be used for the construction of fatigue crack growth rate curves in austenitic and ferritic steels measured in the near-threshold and near-fracture regions by means of a special testing device.

Thermoplastic elastomers are a relatively new group of engineering materials and are increasingly used in various technical applications (i.e., seals, gaskets, damping elements, and membranes) where the fatigue resistance plays an important role. The fracture behavior of elastomers is often characterized using the tearing energy concept, T. However, hardly any data are available for these types of materials. Hence, an unfilled and a filled thermoplastic polyurethane (TPU) type were investigated under cyclic loading conditions. The pure shear specimen configuration was used in the experimental part of this study. Crack growth kinetics curves were determined and the cycle number and the tests frequency dependence of these curves investigated. While a stable crack growth process was observed at 2 Hz the crack growth became unstable above specific test amplitude at 10 Hz.

The reinforcement of concrete structures with laminates of carbon fibers CFRP (Carbon Fiber Reinforced Polymer) began in the 1970’s but laminates were not used extensively until the 1990’s.Nowadays it is one of the most promising technologies due to the good mechanical characteristics of the laminates and their easy manipulation. In the near future, laminates will play a fundamental role in the rehabilitation projects of buildings. Laminates bond to the concrete by means of resins of epoxy type. The capability of the reinforcement depends directly on the proper behavior of the interface laminate-concrete. The laminate helps to bear loads while the concrete is able to transfer stresses to the laminate. The safety factor of the reinforcement can be guaranteed if we can predict the behavior at the interface between both materials. In this work a test of pure shear has been developed to better understand the behavior at the interface between the laminate and the concrete.

The role of the deformation pre-history in high-cycle fatigue properties of copper produced by severe plastic deformation is discussed. The focus is placed on comparison of the structures and mechanical behaviours of two types specimens produced either by rolling or by ECAP, i.e. by the pure shear or simple shear mode, respectively. It is shown that the deformation either by simple or pure shear mode to the same equivalent strain results in alike mechanical properties, both monotonic and cyclic. The significant influence of the initial stages of strain hardening on fatigue is highlighted.

Rubber material properties and useful life evaluation are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, the evaluation of characteristics and useful life prediction of rubber component for elevator cabin were experimentally investigated. The material test and accelerated heat-aging test were carried. Rubber material constants were obtained by curve fittings of simple tension, pure shear and bi-axial tension test data. Heat aging test results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the rubber material and component test several useful life prediction equations for rubber component were proposed. Predicted useful life of rubber component for elevator cabin agreed fairly with the experimental lives.

In order to study the damage mechanism under different stress states of aluminum alloy components, two kinds of representative triaxial stress states were adopted, namely notch tensile and pure shear. The results of study showed: During the notch tensile test, stress triaxiality in the least transverse-section was relatively higher. With increasing applied stress, the volume fraction of the microvoid in notch root was increasing constantly. When microvoid volume fraction reached the critical value, the specimen fractured. During the pure shear test, stress triaxiality almost came up to zero, and there was almost no micro-void but localized shear bands within the specimen. The shear bands resulted from non-uniform deformation constantly under the shear stress. With stress concentrating, the cracks were produced in the shear bands and later coalesced. When the equivalent plastic strain reached the critical value, the specimen fractured. The modified Gurson damage model and the Johnson-Cook model were used to simulate the notch tensile and shear test respectively. Simulated engineering stress-strain curves fit the measured engineering stress-strain curves very well. In addition, the empirical damage evolution equation for the notch specimen was obtained from the experiment data and FEM simulations.

A newly developed resonator in combination with a UDS 200 rheometer allows performing different kinds of measurements. The characteristics of the resonator are its resonant frequency slightly above conventional rheometers, the high sensitivity allowing measurement of fluids with viscosities as low as that of water and the very small oscillation amplitudes. The nonlinear behavior of viscoelastic liquids can be analyzed using parallel superposition of shear. It is known that the parallel complex shear modulus differs from the complex modulus of a fluid at rest. First measurements have shown the ability of the instrument to quantify this effect. At the same time, normal force, shear rate viscosity and complex viscosity can be measured on a sample.

This research aims to investigate strain rate effect on the out of plane shear strength of unidirectional fiber composites. Both glass/epoxy and graphite/epoxy composites were considered in this study. To demonstrate strain rate effect, composite brick specimens were fabricated and tested to failure in the transverse direction at strain ranges from 10-4/s to 700/s. Experimental observations reveal that the main failure mechanism of the specimens is the out of plane shear failure taking place on the plane oriented around 30 to 35 degree to the loading direction. The corresponding out-of-plane shear strength was obtained from the uniaxial failure stress through Mohr-Coulomb strength analysis. In addition, the associated shear strain rate on the failure plane was calculated through the coordinate transformation law. Results show that the out-plane shear strength increases with the increment of the shear train rates. A semi-logarithmic function expressed in terms of the normalized shear strain rate was employed to describe the rate dependence of the out-plane shear strength.

The mechanical properties of rock under high temperature and high geostress are the basic and important information to assess the safety of underground engineering. Based on the environmental conditions of the west route of south-to-north water transfer project in western China, experiments are conducted for a sandstone. The experiments are conducted in stress path of hydrostate, pure shear, and conventional triaxial compression at the temperature of 25°C, 50°C and 70°C. The change of strength and average moduli of the rock with temperatures are studied. By cycle loading and unloading tests, elastic and plastic deformation of the rock are decomposed, it is shown that the plastic deformations of the rock are clearly changed with temperature, while the elastic deformation of the rock seems to be unaffected by the temperature. Moreover, based on the associated plastic flow rule, a constitutive law considering temperature is proposed for the sandstone.