Deformation/strain and stress

The necessary vocabulary, fundamentals and definitions for ‘deformation’, ‘strain’ and ‘stress’ are provided. Types of deformation, incremental or progressive, pure shear and simple shear, deformation regimes, flow lines and vorticity number, shortening, extension and strain measurements are explained. The concept of stress acting on a surface, through its normal and shear components is presented, along with their graphical representation using the Mohr diagram. In the elastic domain that characterizes very small strains, the relationship between stress and strain is discussed through the elastic constants among which the shear modulus and Poisson’s coefficient are notable. Finally, the stress–strain relationships for the ductile (plastic) and viscous behaviours, characteristic of large deformations, are discussed. These form the basis of understanding the rheology of the Earth, and hence Tectonics.

Speckle pattern optimization for DIC technologies

This paper contains the relation between speckle pattern and Digital Image Correlation (DIC). The most important advance in experimental mechanics has been DIC since the strain gage. The deformation (strain) of an object can be visualized by DIC. Among all scientific fields, the DIC Technologies have seen a dynamic increase. The relationship between the paint and the sample - as the patterns mediate the deformation to the cameras - has been the most important technological issue. In this article the method developed for the detection of isolated particles in alloys is used to characterize the spots, which help the best speckle pattern has determined.

The Effect of Deformation Strain on Texture Uniformity in Tantalum Sheet during Asymmetric Cross Rolling

Microstructure and crystallographic texture play an important role in the sputtering target properties. The effect of asymmetric cross rolling (ACR) and deformation strain during ACR on texture homogeneity is not clear. Thus, high-purity tantalum (Ta) plates were ACR to 60% and 87% reduction in thickness. Texture of the rolled Ta sheets in the surface and center layer are characterized via X-ray diffraction (XRD). The XRD results indicate that ACR is effective to weaken the texture gradient existing in the as-received Ta plate. Besides, more homogeneous texture distribution along the thickness can be obtained with the increasing strain during ACR process.

Analysis of plated-hull structure strength against hydrostatic and hydrodynamic loads: A case study of 600 TEU container ships

The assessment of a ship's ability to withstand environmental loads is very crucial. This research focuses on the strength assessment of 600 TEU container ship hulls against hydrostatic and hydrodynamic loads using finite element-based software. Parameter changes in the material types, hull thickness, and ship drafts were performed to compare the structural responses using deformation, strain, and von Mises stress criteria. All of the materials tested were acceptable, where the ASTM A131 Grade AH36 and ASTM A131 Grade AH32 materials have the lowest deformation values and strains. The simulation results regarding plate thickness variation, deformation, strain, and von Mises stress values were smaller as the thickness of the ship structure increased. Moreover, from the draft variation, the structural response due to environmental load was better as the draft of the ship increased.

Microstructure and Strengthening Model of Cu–Fe In-Situ Composites

The tensile strength evolution and strengthening mechanism of Cu–Fe in-situ composites were investigated using both experiments and theoretical analysis. Experimentally, the tensile strength evolution of the in-situ composites with a cold deformation strain was studied using the model alloys Cu–11Fe, Cu–14Fe, and Cu–17Fe, and the effect of the strain on the matrix of the in-situ composites was studied using the model alloys Cu–3Fe and Cu–4.3Fe. The tensile strength was related to the microstructure and to the theoretical strengthening mechanisms. Based on these experimental data and theoretical insights, a mathematical model was established for the dependence of the tensile strength on the cold deformation strain. For low cold deformation strains, the strengthening mechanism was mainly work hardening, solid solution, and precipitation strengthening. Tensile strength can be estimated using an improved rule of mixtures. For high cold deformation strains, the strengthening mechanism was mainly filament strengthening. Tensile strength can be estimated using an improved Hall–Petch relation.