The robot kinematic mapping x = f() generally has multiple distinct solution branches fjf() = x d g for a given end{eeector location x d , where each branch can have a nontrivial manifold structure (as in the case of a redundant manipulator). Learning techniques which exploit known topological properties of the mapping are used to determine the number and nature of these branches. Speciically, ...

In this paper the kinematics, (position, velocities and accelerations) and the dynamics of a 6-RUS parallel manipulator by using the natural coordinates are analysed. One numerical example of kinematics and inverse dynamics is presented.

The optimal design of production in fractured geothermal reservoirs requires knowledge of the resource’s connectivity, therefore making fracture characterization highly important. This study aims to develop methodologies to use resistivity measurements to infer fracture properties in geothermal fields. The resistivity distribution in the field can be estimated by measuring potential differences...

A fracture theory for a heterogeneous aggregate material which exhibits a gradual strainsoftening due to microcracking and contains aggregate pieces that are not necessarily small compared to struttural dimensions is developed. Only Mode I is considered. The fracture is modeled as a blunt smeared crack band, which is justified by the random nature of the microstructure. Simple triaxial stress-s...

Mine earthquakes are serious disasters in coal mines, especially extremely thick hard strata. This study investigates the occurrence mechanism of fracture-type mine Hydraulic fracturing by ground vertical well was used for shock absorption. Dongtan taken as a case study. Field investigation, theoretical analysis, industrial tests, and field monitoring were revealing mechanism. First, mechanical...

Multi-layered plates consisting of DH-36 steel coated by a thick layer of polyurea, for increased blast and impact protection, are of increasing importance to the Department of Defense. A hybrid approach of experiments and simulation was performed to characterize fracture and plasticity of DH-36 Navy steel, which is the first step in creating an accurate model of the composite material. The per...

An important concern in the study of fracture healing is the ability to assess mechanical integrity in response to candidate therapeutics in small-animal systems. In recent reports, it has been proposed that microCT image-derived densitometric parameters could be used as a surrogate for mechanical property assessment. Recently, we have proposed an inverse methodology that iteratively reconstruc...

stress-intensity factors (sifs) are the most important parameters in fracture mechanics analysis of structures. these parameters are evaluated for a stationary crack in functionally graded plates of arbitrary geometry using a novel galerkin based mesh-free method. the method involves an element-free galerkin method (efgm), where the material properties are smooth functions of spatial coordinate...

A key factor that limits the practical implementation of polymer gels is low gel toughness. Here, we present coarse-grained molecular dynamics simulations of the effects of solvent molecular weight on the toughness of entangled and non-entangled polymer gels in the ballistic impact regime. Our results demonstrate that higher molecular weight solvents enhance gel toughness, and that mechanical p...