Elastic-plastic phases

Researchers [6] showed that the microstructure of RubCon has elastic, elastic-plastic, and viscous phases. The amount of elastic in the composite is less in comparison with others, and consequently deformability of RubCon at action a long-term and a short-term loadings in the greater degree is determined by elastic and elastic-plastic deformations. The increase of the strength of RubCon and the modulus of elasticity at compression and the decrease of its ultimate deformations at negative temperatures can be explained by increases in viscous phase viscosity and partial transformation of an elastic-plastic phase of a composite in elastic. The increase in the elastic phase results in embrittlement of the composite but no changes in its stress-strain state. 

An increase in temperature from 20°C up to 50°C has a small effect on RubCon. At a further increase in temperature, it was possible to expect substantial growth of ultimate deformations along with a simultaneous drastic decrease in ultimate compressive strength and modulus of elasticity. At the maximum positive temperature of 80°C, deformability of RubCon increases 2.5 times, ultimate strength is reduced by 40%, the modulus of elasticity decreases by 50%. At rise in temperature the part of an elastic-plastic phase transfers to viscous thus, highly elastic and viscous deformations develop and produce increases in RubCon deformability, and decreases in its ultimate compressive strength and the module of elasticity. 

In this chapter the regimes of mechanical response nonlinear elastic compression stress tensors the Hugoniot elastic limit elastic-plastic deformation hydrodynamic flow phase transformation release waves other mechanical aspects of shock propagation first-order and second-order behaviors. 

Coran and Patel [33] selected a series of TPEs based on different rubbers and thermoplastics. Three types of rubbers EPDM, ethylene vinyl acetate (EVA), and nitrile (NBR) were selected and the plastics include PP, PS, styrene acrylonitrile (SAN), and PA. It was shown that the ultimate mechanical properties such as stress at break, elongation, and the elastic recovery of these dynamically cured blends increased with the similarity of the rubber and plastic in respect to the critical surface tension for wetting and with the crystallinity of the plastic phase. Critical chain length of the rubber molecule, crystallinity of the hard phase (plastic), and the surface energy are a few of the parameters used in the analysis. Better results are obtained with a crystalline plastic material when the entanglement molecular length of the... 

DE - A Two-Dimensional Eulerian Hydro-dynamic Code for Computing One-Component Reactive Hydrodynamic Problems , Los Alamos Scientific Laboratory Report LA-3629-MS (1966) 23b) C.L. Mader, "FORTRAN-SIN - A One-Dimensional Hydrodynamic Code for Problems Which Include Chemical Reactions, Elastic-Plastic Flow, Spalling, and Phase Transitions , Los Alamos Scientific Laboratory Report LA-3720(1967) 24) R.C. Sprowls, "Com-... 

Consider a continuous fiber-reinforced ceramic as a multiphase system where the individual phases are parallel to one another and to the uniaxial loading direction. The fibers (or fiber bundles), matrix, and interface zone are treated as individual phases. In general, each phase undergoes elastic-plastic (creep) deformation. In the present analysis, the creep rate of each phase, e is assumed to obey a general creep law of the following form... 

The mechanical properties of rapidly polymerizing acrylic dispersions, in simulated bioconditions, were directly related to microstructural characteristics. The volume fraction of matrix, the crosslinker volume in the matrix, the particle size distribution of the dispersed phase, and polymeric additives in the matrix or dispersed phase were important microstructural factors. The mechanical properties were most sensitive to volume fraction of crosslinker. Ten percent (vol) of ethylene dimethacrylate produced a significant improvement in flexural strength and impact resistance. Qualitative dynamic impact studies provided some insight into the fracture mechanics of the system. A time scale for the elastic, plastic, and failure phenomena in Izod impact specimens was qualitatively established. The time scale and rate sensitivity of the phenomena were correlated with the fracture surface topography and fracture geometry in impact and flexural samples. 

The general tablet compaction process normally is described by a number of sequential phases rearrangement, deformation (elastic, plastic) of initial particles, fragmentation, and deformation of fragments. Particle-surfaces are brought into close proximity and interparticulate attraction or bonds will be formed. Similar conditions will prevail with the effervescent tablets. 

The residual stress effect is considered by the separate analysis model and unified analysis model, and the results are shown in figures 3(a) and (b). Figure 3(a) corresponds to the elastic analysis and it is seen that the separate analysis model and unified analysis model give the same resultant stress Figure 3(b) corresponds to the eltistic-plastic analysis tmd it is seen that the resultant stresses found from the two models are different. This is because in the elastic analysis the two responses in phase I and phase II are both linear and the resultant response can be obtained from a direct superposition of the two separate ones. In the elastic-plastic analysis, however, the two separate responses are both nonlinear and the separate analysis model based on the direct superposition of the two separate responses is no longer suitable. 

In the elastic-plastic analysis, the separate ancilysis model and the unified analysis model give the different results because the two responses of the cooling and working phases are both nonlinear. In this case, the separate analysis model is no longer suitable and the unified analysis model should be used.. 

The formation and evolution of multiple waves becomes more complicated when chemical reactions or phase transitions occur. Volume decreasing phase transformations cause the pressure at point B in Figure 2 and Figure 7 to decrease with time. This common phenomenon is known as elastic precursor decay in elastic-plastic wave system. [9] The timescale for this pressure decay depends primarily on the timescale for the chemical reaction or phase transition that gives rise to the 2" wave. 

Substrate composition and phases Surface hardness and roughness at interface Grain size/microstructure Anisotropy in structure and properties Areal variation and batch-to-batch variation Elastic/plastic mechanical properties Fracture mechanics Flaw population and distribution Strain rate effects... 

There has been the question why the TPV materials with ductile thermoplastic matrix display rubber elasticity. Several models have been suggested to answer this question (41 7). Inoue group first analyzed the origin of mbber elasticity in TPVs (43). They constructed a two-dimensional model with four EPDM mbber inclusions in ductile PP matrix and carried out the elastic-plastic analysis on the deformation mechanism of the two-phase system by finite-element method (FEM). The FEM analysis revealed that, even at highly deformed states at which almost the whole matrix has been yielded by the stress concentration, the ligament matrix between mbber inclusions in the stretching direction is locally preserved within an elastic limit and it acts as an in-situ formed adhesive for interconnecting mbber particles. 

After the introduction of polar sulfonic functions or quaternary ammonium groups into the polystyrene network, the material becomes hydro-phihc water solvates the polar groups of the polymer chains, thus plasticizing the polymeric phase. As in the case of removing toluene from nonpolar sorbents by drying, the removal of water from the hydrophilic matrices of ion-exchange resins is accompanied mainly by non-elastic, plastic, deformations of the polymer network stressed by capillary contraction. Under these conditions of plasticization of the polymer phase by water, the desweUing anomaly manifests itself primarily as an abrupt decrease in the bead volume, with a subsequent slow approach to an... 

Fundamental Properties of Polymers, Metals and Ceramics (e.g., strength in compression, tension and bending elasticity/plasticity failure mechanisms phase diagrams transition temperatures surface roughness hydrophobicity) Mechanical Properties of Biological Tissues (e.g., elastic viscoelastic, hysteresis, creep, stress relaxation)... 

Strength, unlike elastic modulus, is not even theoretically a readily determinable quantity. Overall elastic-plastic deformation in a structural adhesive might be describable in terms of intermolecular forces and models of viscous flow, but not at the discontinuous moment of fracture. In fact overall behaviour loses sight of the fact that it is normally isolated phenomena that control the magnitude of joint strength and the locus of failure (see Stress distribution mode of failure). The term isolated phenomena refers to voids, cracks, second phase material, and so on, which can act as stress concentrators. Clearly, it would be unwise to suggest that an adhesive bond tester should merely locate and size voids and cracks, as whether or not such a defect is active depends upon where it lies in the working stress pattern of the structure. 

Multiphase computations, as elastic-plastic computations follow up the elastic computations and there is a synchronization phase between those two. The existence of the synchronization step between the two phases of the computation requires that each phase be individually load balanced. 

Kang, S.-H. Im, Y.-T. (1987). Three dimensional thermo-elastic-plastic finite element modeling of quenching process of plain-carbon steel in couple with phase transformation. Int.. Mech. Sci., Vol. 49,423-439. 

Main parameters of the bilinear isolators are the base mass shown by /Wj (similar linear case) isolator stififiiess in elastic phase shown by and its stififiiess in plastic phase its time period in elastic phase and after yielding shown by... 

In this study, the values of and 7 are assumed to be about 2.5 cm and 0.142, respectively, given in references (Matsagar Jangid, 2004 Rodellar Manosa, 2003). Finally, damping ratio of elastic phase and that of the plastic phase e... 

For improvement of impact strength, incorporation of rubbery dispersions into plastics is an eflFective method. The impact energy W is given by the elastic energy Eelongation ratio, respectively. For plastics incorporated with rubber particles, the deformation is different in both phases. The M s for the rubbery phase-1 and the plastic phase-2 are proportional to their volume fraction 0, and the total energy is... 

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