Here, we investigate the ultrastructural origins of the strength of bone, which is critical for proper physiological function. A combination of dual nanoindentation, three-dimensional elastic-plastic finite element analysis using a Mohr-Coulomb cohesive-frictional strength criterion, and angle of repose measurements was employed. Our results suggest that nanogranular friction between mineral pa...

-We describe slip-rate dependent friction laws based on the Coulomb failure criteria. Frictional rate dependence is attributed to a rate dependence of cohesion c and friction angle qS. We show that differences in the stress states developed during sliding result in different Coulomb friction taws for distributed shear within a thick gouge layer versus localized shear within a narrow shear band ...

Metal forming processes, compared with machining ones, reduce production steps and increase manufacturing speed in addition to saving raw material. In this paper, forming process of column of a steering mechanism is investigated by finite element analyses and experimental tests; and optimum die design parameters are found. Forming process parameters including die opening angle, bearing length, ...

One of the most important factors in determining the depth of foundations in structures adjacent to the water flow is the scouring phenomenon; the scouring is a phenomenon caused by the interactions between water flow and erodible bed materials, which causes the removal of sediments where hydraulic structures are located, including bridge piers. Every year, a great number of bridges are damaged...

calculation of lateral earth pressure on retaining walls is one of the main issues in geotechnics. the upper and lower bound theorems of plasticity are used to analyze the stability of geotechnical structures include bearing capacity of foundations, lateral earth pressure on retaining walls and factor of safety of slopes. in this paper formulation of finite element limit analysis is introduced ...

naturally occurred soil deposits inherit heterogeneity and anisotropy in their strength properties. the main purpose of this paper is to model the soil stratum with anisotropy consideration and spatially varying undrained shear strength by using random field theory coupled with finite difference numerical analysis to evaluate their effect on the bearing capacity of the shallow foundations. in t...

Compared with plain soil, polypropylene (PP) fiber-reinforced soil has markedly improved mechanical properties and can be used in slope protection projects. To investigate the reduction law of antierosion ability parameters PP loess under dry-wet (D-W) cycles freeze-thaw (F-T) cycles, we took from Yan’an, China, mixed them fiber, did shear strength tests, disintegration permeability tests D-W F...

Mobility analysis is crucial to fast, safe, and autonomous operation of planetary Wheeled Mobile Robots (WMRs). This paper reviews implemented odometry techniques on currently designed WMRs surveys methods for improving their mobility traversability. The are categorized based the employed approaches ranging from signal-based model-based estimation terramechanics-based, machine learning, global ...