Abstract:
A push-pull force transducer comprising a unitary body formed from a crystalline substrate. The body comprises first and second mounting elements for mounting the force transducer to first and second structures, and first and second force sensing elements connected to the mounting elements. Each force sensing element has first and second ends, a line extending from the second to the first end defining a force sensing axis for the force sensing elements. The force sensing elements are oriented with their force sensing axes parallel to and aligned with one another. The first force sensing element has its first end connected to the second mounting element and its second end connected to the first mounting element. The second force sensing element has its first end connected to the first mounting element and its second end connected to the second mounting element. Also described are embodiments utilizing strain relief flexures and an embodiment featuring a leveraged design.
Abstract:
II s'agit d'un capteur de micro-force comportant une plaque monolithique comprenant une première zone (1') délimitant un premier évidement (1), devant être maintenue en position par rapport à un support, une seconde zone (2') reliée à la première zone (1') délimitant le premier évidement (1) et un second évidement (2), une poutre de mesure (4) en travers du premier évidement (1) ayant une première extrémité (40) encastrée à la première zone (1') et une seconde extrémité (41) reliée à la seconde zone (2'), une poutre d'excitation (3) en travers du second évidement (2) ayant deux extrémités encastrées à la seconde zone (2), étant équipée d'au moins un élément d' excitation (5), une troisième zone (8) reliée à la première zone (1') et une poutre effectrice (7) présentant une extrémité libre (9) devant recevoir la force (F) à mesurer et une extrémité encastrée (9') à la troisième zone (8), une quatrième zone (15) reliant l'extrémité encastrée (9') de la poutre effectrice (7) à la seconde extrémité (41) de la poutre de mesure (4) qui est équipée d'un élément de mesure (6).
Abstract:
A sensor interface is disclosed including a flexible substrate in which are embedded sensors for measuring physical parameters such as temperature, displacement, velocity, acceleration, stress, strain, pressure and force present between objects such as a railcar bearing and a truck side frame. The substrate is positioned between the objects of interest Electronic components such as a data processing unit, a data storage device, a communication device and a power source may also be embedded within the substrate. The electronic devices communicate with one another and the sensors to process signals generated by the sensors indicative of the parameters being measured.
Abstract:
Metal creep effects in force sensors, accelerometer or coriolis sensors can be reduced by disposing a chromium adhesion layer over less than an entirety of the sensing element. The sensing element can be formed of multiple vibratable beams. On patterned adhesion layers conductive layers are bonded partly to vibratable beams. The reduced bonded areas reduce stress in the conductive paths.
Abstract:
Tuning forks are manufactured from planar, preferably single crystal (6), silicon by etching channels (5) in the silicon to define the tines and then cutting the silicon into individual elements each comprising a tine having a thicker end portion. Two elements (6, 7) are bonded together to form a tuning fork. Alternatively two etched wafers may be bonded together and then cut into individual tuning fork structures. Piezoelectric transducer elements (8) may be formed on the tuning forks by deposition.
Abstract:
In an embodiment an electric circuitry includes at least one first ring oscillator and at least one second ring oscillator being arranged on a substrate in different orientations, a time-to-digital converter having a converter ring oscillator and a processing circuit, wherein a first time is determined by a period duration of at least one first ring oscillator, this period duration depending on the propagation delay time of first delay elements, wherein a second time is determined by a period duration of at least one second ring oscillator, this period duration depending on the propagation delay time of second delay elements, and wherein the processing circuit is configured to determine a magnitude of the strain applied on the substrate based on a first state of the converter ring oscillator at the first time and a second state of the converter ring oscillator the second time.
Abstract:
A resonant sensor comprises a proof body subjected to a torque of forces produced by an external mechanical structure, the body comprising: a first and a second interface that can each come into contact with the structure; at least two sensitive zones arranged between these two interfaces; a sensitive zone formed by a plate embedded in a frame secured mechanically to the interfaces, the plate able to resonate under the effect of local mechanical excitations produced at particular points by excitation transducers bearing the plate at several resonant frequencies, sensors picking up the resonant signals produced at the particular points, measurement means measuring the resonant frequency shifts of signals which are linear combinations of the resonant signals picked up, the shifts being a function of mechanical stresses induced by the forces and transmitted to the plate by the frame, the components of the torque of forces being determined from the resonant frequency shifts measured on the plates of the sensitive zones.
Abstract:
The present invention relates to a structural health monitoring system, for example a system used in the non-destructive evaluation of an aircraft structure. The present invention provides a method and apparatus for evaluating one or more anomalies within a structure using a structural health monitoring system that includes at least three transducers arranged in operative contact with the structure such that no two transducers are aligned to be parallel. A transducer excites an elastic wave that propagates through the structure, and reflections from any anomalies within the structure are collected by the three transducers. These collected signals are analyzed to identify an anomaly within the structure. Time of flight techniques are used to determine the location of the anomaly.
Abstract:
A non-powered impact recorder is disclosed. The non-powered impact recorder includes a resonator tuned for a resonant response within a predetermined frequency range. A reduced cross-sectional area portion is formed within the resonator and configured to structurally fail when the resonator experiences the resonant response. Additionally, the non-powered impact recorder includes an electric circuit element disposed about the reduced cross-sectional area portion of the resonator. Upon structural failure of the resonator, the electric circuit element is broken to cause a discontinuity in the electric circuit element. Interrogation of the discontinuous electric circuit element facilitates approximation of impact frequency and/or impact energy.