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there are accumulations of dislocations depending on the grain size and stress concentration, which cause sliding in the neighboring grain. The smaller the grain size, the greater the number of these barriers on the path of sliding dislocations and the higher the stress required to maintain plastic deformation in the early stages [40]. The mechanism of solid solution hardening is that the dissolved atoms act as weak......
the measured elastic modulus of MMCs [39,40]. Clustering of CNTs-Al2O3 and porosities causes stress concentration and unexpected fracture thus, lower strength. Fig. 7 HRTEM micrographs of Al-2CNTs-10Al2O3.... The agglomeration of CNTs- Al2O3 NPs provided sites for crack initiation and acted as a stress concentration sites. According to CASATI and VEDANI [3], agglomerated regions and also the aggregation......
of rock joints, and proposed the B–B model. The shear strength of a rough rock surface depends on the relationship between the roughness, the rock strength and the normal stress, and can be defined by the following empirical equation: (1) where τ is the shear strength of the rough rock surface; σn is the effective normal stress......
nanoparticles to the AA2024 matrix on the hardness, ultimate tensile strength, yield strength and elongation of the alloy are shown in Fig. 8. Figure 8(b) represents the comparative true stress..., by creating obstacles to the dislocations motion, the reinforcing particles increase the threshold stress required for dislocations mobility and strengthen the nanocomposite [43,44]. Another......
difference is that for the shorter holding time, the amount of AlMnFe intermetallics and silicon needles is less, compared to that in the sample brazed during 4 min. Due to non-uniform stress distribution and the resulting stress concentration by the presence of needle-like morphology of silicon and intermetallics, the mechanical properties of the assembly would be decreased [32]. Nonetheless, the higher......
on the experimental studies. References [1] AL-TAMIMI A A, PEACH C, FERNANDES P R, CSEK A, BARTOLO P J D S. Topology optimization to reduce the stress shielding effect for orthopedic applications [J..., 2011, 27(2): 131-138. [3] NIINOMI M, NAKAI M. Titanium-based biomaterials for preventing stress shielding between implant devices and bone [J]. International Journal of Biomaterials, 2011, 2011: 10. [4......
·℃). 图4 稳态剪切摩擦应力随温度的变化 Fig. 4 Change of steady shear friction stress with temperature 1.3 挤压缺陷产生机理与仿真模型验证 为准确描述挤压出模口型材横截面上材料流速的均匀程度,引入流速均方差(SDV)作为衡量型材挤压金属流动均匀性的评价指标,其定义为.vi为型材横截面上第i个节点... on profile cross-section 图14 焊合室焊合压力分布 Fig. 14 Welding pressure distribution in welding chamber 表5 焊合室的焊合压力,有效应力和挤压力对比 Table 5 Comparisons of mean welding pressure, flow stress......
by a high temperature annealing process to release the residual stress is required for Fe-6.5Si compacted core. Thus the insulating layer with high heat resistance, high pressure endurance, high stability... phosphate concentration gives rise to stress accumulation in interface, and thus the coating layer becomes more susceptible to breakdown and damage. And for low concentration, the phosphate coating......
: σ=σikD-1/2 (1) where D is the grain size, σi is friction stress, and k is a material constant parameter... to TMAZ. The formation of nano-composite in the SZ improved the stress transfer from the matrix to the reinforcement particles and increased the tensile strength. ABDOLAHZADEH et al [27] reported......
in the fracture of the R-DC alloy are more in number, smaller in size, and larger in depth, which supports the higher strength and plasticity of the R-DC alloy. The maximum stress (σmax) experienced...; (4) where α is the stress concentration coefficient of the pore, S0 is the cross-sectional area of the specimen, F is the tensile force, and μ is the fraction of the pore area. Compared with the DC......