2,935 research outputs found
Design and analysis of a piezoelectric film embedded smart cutting tool
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2012 Institution of Mechanical Engineers.The condition of a cutting tool is an important factor for manufacturing processes. Tool wear has a strong influence on the cutting forces, resulting in poor surface roughness and dimensional accuracy of the workpiece. Therefore, the use of a dynamometer to measure cutting forces is a well-known approach, but it has several limitations such as high cost, poor performance in harsh industrial machining environments and possible interference with cutting dynamics. This article presents a novel smart cutting tool using a separate single-layer piezoelectric film as the sensing unit to detect the orthogonal cutting force. Simulations were performed to validate the feasibility of the proposed design, and the model was also able to detect better force measurement sensitivity. Furthermore, cutting trials were carried out to validate cutting tool performance experimentally
Discrete Quantum Field Theories and the Intersection Form
It is shown that the standard mod- valued intersection form can be used to
define Boltzmann weights of subdivision invariant lattice models with gauge
group . In particular, we discuss a four dimensional model which is
based upon the assignment of field variables to the -simplices of the
simplicial complex. The action is taken to be the intersection form defined on
the second cohomology group of the complex, with coefficients in .
Subdivision invariance of the theory follows when the coupling constant is
quantized and the field configurations are restricted to those satisfying a
mod- flatness condition. We present an explicit computation of the partition
function for the manifold , demonstrating non-triviality.Comment: 10 pages, Latex, ITFA-94-1
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Characteristics of a 9mm triple-beam tuning fork resonant sensor
This paper describes the design and testing of the first miniaturised metallic triple-beam tuning fork resonant sensors for use in force, pressure and torque measurement applications. The new devices with 9mm length vibrating tines have resulted in over a 40% reduction in size when compared to previously tested resonators. The four fold increase in operating frequency to 26 kHz, with Q factors in air up to 4000, provides additional benefits for resolution, accuracy, range and overload capability. Measurement repeatability of at least 0.02% of span levels for torque transducers employing the sensors are quoted. Results of characterisation over the temperature range -30oC to +90oC are given
Accuracy and Repeatability Tests on 6D Measurement Arm.
We present kinematic structure of measurement arm along with its construction restrainsoriginating from using only accelerometers for determining relative positions of links. Method of calculating position of arm's end in relation to its base basing on orientation of individual links is presented. Accuracy and repeatability tests were performed using custom made test stand. The description of test stand, measurements procedures for last link changing its position in Cartesian directions and orientation in vertical axis is also included in the paper. These changes were justified in context of links orientation in relations to global coordinate system. Obtained tests results are presented and analyzed
Wilson Loops, Bianchi Constraints and Duality in Abelian Lattice Models
We introduce new modified Abelian lattice models, with inhomogeneous local
interactions, in which a sum over topological sectors are included in the
defining partition function. The dual models, on lattices with arbitrary
topology, are constructed and they are found to contain sums over topological
sectors, with modified groups, as in the original model. The role of the sum
over sectors is illuminated by deriving the field-strength formulation of the
models in an explicitly gauge-invariant manner. The field-strengths are found
to satisfy, in addition to the usual local Bianchi constraints, global
constraints. We demonstrate that the sum over sectors removes these global
constraints and consequently softens the quantization condition on the global
charges in the system. Duality is also used to construct mappings between the
order and disorder variables in the theory and its dual. A consequence of the
duality transformation is that correlators which wrap around non-trivial cycles
of the lattice vanish identically. For particular dimensions this mapping
allows an explicit expression for arbitrary correlators to be obtained.Comment: LaTeX 30 pages, 6 figures and 2 tables. References updated and
connection with earlier work clarified, final version to appear in Nucl.
Phys.
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