摘要:
A fretting fixture accessory for a_test machine (10) that induces high-cycle fatigue (at kilohertz vibration rates) in a specimen of a material under test. The fretting fixture (20) is clamped to the test specimen (21), for the purpose of testing for fretting damage. The fixture (20) is designed to provide both the normal and shearing forces that result in fretting damage.
摘要:
A column assembly for use in conjunction with a test machine, for inducing high-cycle fatigue (at kilohertz vibration rates) in a specimen of a material under test. The column assembly has isolation masses, a specimen grip, and two actuators, the latter for imparting dynamic forces to the test specimen. The actuators are arranged on the column assembly asymmetrically relative to the test specimen.
摘要:
A test machine (10, 40, 60) for inducing high-cycle fatigue (at kilohertz vibration rates) in a specimen of a material under test. Each test machine (10, 40, 60) provides both dynamic and static loading. One embodiment is an SEM-compatible machine (10), having an inner frame (11) containing symmetrical components on either side of a stationary node. The specimen is placed at this stationary vibration node. Dynamic loading is the result of vibrations provided by two piezoelectric actuators (16) inside the frame (11), one on each side of the node. Static loading is provided by means of two stress rods (12), each extending from an end plate (11a) into the frame (11). A pair of cylindrical couplers (14) is also inside the frame, one coupler (14) on each side of the node. Each coupler (14) is attached to an associated piezoelectric actuator (16) and stress rod (12) such that the static and dynamic loads are transferred to the couplers (14). The specimen is held between the inner faces of each coupler 14 such that the loading is transferred to the specimen. The static and dynamic loading applied to the specimen are independent of each other and separately controllable.
摘要:
An externally controllable circuit breaker includes a set of main contacts, an operating mechanism for opening and closing the main contacts; and a set of secondary contacts electrically connected in series with the main contacts. A control mechanism to open and close the secondary contacts includes an electromagnet with an armature having a first position, which opens the secondary contacts, and a second position, which closes the secondary contacts. The electromagnet also includes a coil electrically interconnected with the main contacts for energization therefrom and adapted for control by one or two external signals from one or two external contacts to operate the armature between the first and second positions.
摘要:
A method of maintaining and controlling a plurality of wireless light fixtures includes providing the light fixtures in a structure, wirelessly receiving respective operational data from each of the light fixtures at a central location, aggregating the received respective operational data to form an aggregation of operational data, and analyzing at least a portion of the aggregation of operational data. The method further includes performing one or both of (i) controlling the operation of a first selected one or more of the light fixtures based on a result of the analyzing step by wirelessly transmitting respective operational commands from the central location to each of the first selected one or more of the light fixtures, and (ii) causing a maintenance related action to be taken with respect to each of a second selected one or more of the light fixtures based on a result of the analyzing step.
摘要:
A method of maintaining and controlling a plurality of wireless light fixtures includes providing the light fixtures in a structure, wirelessly receiving respective operational data from each of the light fixtures at a central location, aggregating the received respective operational data to form an aggregation of operational data, and analyzing at least a portion of the aggregation of operational data. The method further includes performing one or both of (i) controlling the operation of a first selected one or more of the light fixtures based on a result of the analyzing step by wirelessly transmitting respective operational commands from the central location to each of the first selected one or more of the light fixtures, and (ii) causing a maintenance related action to be taken with respect to each of a second selected one or more of the light fixtures based on a result of the analyzing step.
摘要:
A method for measuring strain in a sample of material. A reference image is obtained of a surface of the sample. A test machine is used to apply a load to the sample, as determined by a control signal from a system processor. A measurement image is then obtained, and test points on the reference image are located on the measurement image, using an image processor programmed to perform machine vision. The displacements between the location of the test points on the two images are determined. These displacements are used to calculate strain. Each new strain value may be used by the system processor to determine a next load value, so that the load is adjusted in terms of strain parameters.
摘要:
A liquid stream (13) and a detector (12) and a computer (11) which operate to observe properties in the composition of the fluid stream and compare detected data from observed samples with standards and in accordance with parameters established by calibration calculate the characteristics of the observed samples.An integral but segmented liquid stream (13) flows through the analysis system (10) to provide liquid segments of observed sample and reagent. A detector (12) scans data from the samples at the interface between these segments and information relating to the composition at the interface is analyzed by a mathematical model that permits comparison of the detected data from successively observed samples with standards and thus determines the characteristics of the samples. The segmented integral liquid stream (13) is fashioned by step pulsing of discrete segments of reagents and samples and transporting the discrete segments to a detector (12). The analysis system (10) is driven by a vacuum assembly (16) and valves to form the segments in the absence of air so that the respective sample and reagent segments interface with each other.A plurality of source tanks (20) provide the liquid samples and reagents for the segmented, integral liquid stream (13) and the vacuum assembly (16) creates a force which forms and drives the samples and reagents through conduit means (21), (23), (27), (14) and (38) to the detector (12).
摘要:
An electronic controller, connected to a digital communication network, is responsive to commands from a master controller to control solenoid operated circuit breakers. The electronic controller also determines the status of all circuit breakers and reports back to the master controller to verify that the command from the master controller was executed and to provide historical data regarding the status of the circuit breakers. The electronic controller is synchronized to the same alternating current (AC) power source as the circuit breakers to control the operation of the respective circuit breakers to minimize electromagnetic interference (EMI) caused by the switching of the circuit breakers. The electronic controller further controls the operation of the circuit breakers to reduce the duty cycle of the power supply for the circuit breaker solenoids.
摘要:
A method for measuring a physical property of a polymer sample includes measuring a portion of a Raman spectrum of the polymer sample, determining a value of a preselected spectral feature from the portion of the Raman spectrum, and comparing the determined value to reference values. The value of the preselected spectral feature depends functionally on the physical property. The reference values relate the preselected spectral feature to the physical property. A probe includes a housing; first, second, and third optical systems attached to the housing; and a first optical filter located along a first direction. The first optical system is to collimate an illumination beam along the first direction. The first optical filter is to produce substantially monochromatic light and is insertable into the probe without substantially affecting an alignment between the probe and the sample. The second optical system is to focus light from the first optical filter on the sample and to collimate scattered light from the sample along a second direction. The third optical system is to focus scattered light from the second direction onto an aperture.