Reconstruction and monitoring of displacement and strain fields is an important problem in engineering. We analyze the remote and nonobtrusive methods of strain measurement based on photogrammetry and Digital Image Correlation (DIC). The method is based on covering the photographed surface with a pattern of speckles and comparing the images taken before and after the deformation. In this study,...

Craniofacial morphology varies among individuals, which is regulated by the interaction between genes and the environment. Soft-diet feeding is a widely-used experimental model for studying the association between the skeletal morphology and muscle-related loading on the bone. Traditionally, these studies have been based on linear and angular measurements provided on two-dimensional (2D) radiog...

A new technique for computation structural instability points using the finite element method is presented. The approach is based on the estimation of critical displacement pattern by writing an approximation of the tangent stiffness singularity condition at the instability point. The critical load is subsequently computed by using a secant load-displacement relationship. Details of this proced...

Mapping full-field displacement and strain changes on the Earth’s surface following an earthquake is of paramount importance to enhance our understanding of earthquakemechanics. Currently, aerial and satellite images taken preand postearthquake can be processed with sub-pixel correlation algorithms to infer the co-seismic ground deformations (e.g., [1, 2]). However, the interpretation of this d...

This paper exploits the concept of stabilized finite element methods to formulate stable mixed stress/displacement and strain/displacement finite elements for the solution of nonlinear solid mechanics problems. The different assumptions and approximations used to derive the methods are exposed. The proposed procedure is very general, applicable to 2D and 3D problems and independent of the const...

We investigate low-energy deformations of a thin elastic sheet subject to a displacement boundary condition consistent with a conical deformation. Under the assumption that the displacement near the sheet’s center is of order h| logh|, where h ! 1 is the thickness of the sheet, we establish matching upper and lower bounds of order h2| logh| for the minimum elastic energy per unit thickness, wit...

residual gas saturation is one of the most important parameter in determining recovery factor of water-drive gas reservoir. visual observation of processes occurring at the pore level in micromodels can give an insight to fluid displacements at the larger scale and also help the interpretation of production performance at reservoir scale. in this study experimental tests in a glass micromodel w...

This paper introduces two real-time elastography techniques based on analytic minimization (AM) of regularized cost functions. The first method (1D AM) produces axial strain and integer lateral displacement, while the second method (2D AM) produces both axial and lateral strains. The cost functions incorporate similarity of RF data intensity and displacement continuity, making both AM methods r...

Statistical Analysis of a Three-dimensional Axial Strain and Axial-shear Strain Elastography Algorithm. (August 2011) Mohan Li, B.S., University of Science and Technology of China Chair of Advisory Committee: Dr. Raffaella Righetti Pathological phenomena often change the mechanical properties of the tissue. Therefore, estimation of tissue mechanical properties can be of clinical importance. Ult...

Background Advanced measures of cardiac mechanics such as left ventricular (LV) strains can be used in conjunction with classical biomarkers to gauge cardiovascular health and improve prediction of patient outcomes. Several imaging techniques, including displacement-encoded magnetic resonance imaging (DENSE), are used to non-invasively assess cardiac mechanics. These data are predominantly acqu...