Topic
Screw axis
About: Screw axis is a research topic. Over the lifetime, 674 publications have been published within this topic receiving 7774 citations. The topic is also known as: Screw Axis & helical axis.
Papers published on a yearly basis
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Papers
TL;DR: An analytical model is presented to describe how the position and direction errors are inversely proportional to the rotation magnitude, and that they are much more error-prone than the relatively well-determined rotation and translation magnitudes.
499 citations
TL;DR: A relaxation-type calculation of the structure of the dislocation core has been made for the ½ 〈111〉 screw dislocation in b.c. crystals, using a variety of central-force potentials as discussed by the authors.
Abstract: A relaxation-type calculation of the structure of the dislocation core has been made for the ½ 〈111〉 screw dislocation in b.c.c. crystals, using a variety of central-force potentials. Two stable configurations were found, corresponding to the centre of the dislocation being along either the left-hand or the right-hand type of three-fold screw axis in the crystal. These two configurations differed only in the very centre. For both configurations and for all potentials, the core structure possessed three-fold symmetry, the largest displacements being in the directions in which displacements on (211) type planes were in the twinning sense. The structure can be described by a combination of large displacements on {110} type planes, plus ‘stacking faults’, 1–2b wide on {211} type planes in the twinning sense only. An investigation of the effect of boundary conditions showed that any errors caused by incomplete relaxation were negligible, and that changing the initial dislocation position or the positi...
469 citations
TL;DR: An attempt to determine a unique axis of rotation that can consider the movement of two dynamic body segments simultaneously, and then compared its performance in a survey against a number of previously proposed techniques.
295 citations
24 Apr 1988
TL;DR: The Moore-Penrose generalized inverse solution for the contact interaction can be modeled by three components of forces (zero moments) is shown to yield a solution vector such that the difference between the forces at any two contact points projected along the line joining the two points vanishes.
Abstract: The problem of force distribution in systems involving multiple frictional contacts between actively coordinated mechanisms and passive objects is examined. The special case in which the contact interaction can be modeled by three components of forces (zero moments) is particularly interesting. The Moore-Penrose generalized inverse solution for such a model (point contact) is shown to yield a solution vector such that the difference between the forces at any two contact points projected along the line joining the two points vanishes. Such a system of contact forces is described by a helicoidal vector field which is geometrically similar to the velocity field in a rigid body twisting about an instantaneous screw axis. A method to determine this force system is presented. The possibility of superposing another force field which constitutes the null system is also investigated. >
259 citations
TL;DR: The patellar tendon moment arm remained roughly constant across individuals when normalized by femoral condyle width, suggesting that anatomical differences play a large role in determining the moment arm of the extensor mechanism.
211 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2024 | 4 |
| 2023 | 5 |
| 2022 | 9 |
| 2021 | 8 |
| 2020 | 14 |
| 2019 | 18 |