31 results about "Critical length" patented technology

An online method, system, and computer-readable code for remotely monitoring radiant energy emitted from a turbine blade (106), which may be undergoing an incipient degradation, such as a crack, in a relatively low-temperature, and saturated steam environment of the low pressure stage of a steam turbine. The method and system provide sufficient temporal and spatial resolution to obtain high quality infrared images of the blade areas of interest enabling the system to identify the crack at any of those areas of the blade prior to such a crack growing to a critical length.

An apparatus for monitoring the structural integrity of a component. A monitoring structure is applied to a component that is subject to structural degradation. The monitoring structure includes an electrical conductor that becomes cracked if the component becomes structurally degraded. When the component is a ductile metal component that may be degraded by bending, the electrical conductor is formed of a brittle material that cracks when the ductile metal component is bent. When the component is a brittle ceramic heat shield wherein a crack having a critical length is of concern, the electrical conductor is located at a predetermined location wherein a critical length crack in the component will propagate into the conductor. A crack in the electrical conductor is detected with a monitoring device to indicate a degraded structural condition in the component.

The radiographic image conversion panel for mammography includes a phosphor layer formed on a rectangular substrate having first and second pairs of two parallel sides, and sealed with a moisture-proof protective film. The phosphor layer is positioned on the substrate such that a distance from at least one side of the first pair to an adjacent end of the phosphor layer is shorter than a critical bonding length being a shortest bonding length long enough to provide a predetermined level of moisture-proof effect and distances from two sides of the second pair to adjacent ends of the phosphor layer are not shorter than the critical length. A seal bonding layer is formed in areas of the second distance, and on a side surface having the at least one side or on the side surface and a rear surface of the substrate. The phosphor layer may be formed in a recess formed in the substrate.

The invention discloses a transverse-furrow and sequential-ridge mellow soil anti-corrosion farming method of a purple soil slope farmland and particularly relates to the field of a soil erosion management technique of the purple soil slope farmland. In the method disclosed by the invention, a transverse furrow is excavated along the contour line on the purple soil slope farmland at the slope length interval which is less than the rill erosion generation critical length of the modified slope surface; the cross section of the transverse furrow is in an arc shape; the formed transverse furrow divides the whole slope farmland plot into multiple small farming units in the transverse slope direction; the two ends of the transverse furrow are connected with the original drainage furrows at the two ends of the slope farmland plot; and the integral farming terrain conditions with alternate furrows and ridges are formed by adopting a sequential-slope ridging farming mode, i.e. alternately farming and ridging in the sequential slop direction and reverse slop direction. The method disclosed by the invention can reduce the water and soil loss and prevent and control the soil erosion of the slope farmland, is beneficial to the enhancement of the water content in the soil of the farmland plot in the descending direction of the transverse furrow, improves the drought resistance of crops, maintains the agricultural productivity of the slope farmland and realizes the sustainable utilization of slope farmland water and soil resources.

The invention discloses a monitoring and testing method, including acquisition of satellite monitoring sensitivity, for an electric-transmission-line mountain fire satellite monitoring system. The monitoring and testing method includes selecting a testing satellite, an open site, a season, weather, time and orbit azimuth angle conditions, preparing a ground monitoring and measuring device, taking firewood as a flaming material, laying a fire ground at the center of the site, recording coordinates of the fire ground, setting fire to the fire ground before satellite transition, observing a quick satellite view in real time and recording time spent by system preprocessing during satellite transition, repeating fire-point judgment after pre-processing, observing whether the satellite can find the test fire ground or not until finding the critical length of the testing satellite finding the fire ground, and squaring the critical length to acquire the sensitivity of the testing satellite. The monitoring and testing method can be used for acquiring sensitivity, distortionless reception range and fire-point judgment threshold of the monitoring system under the conditions such as different weather and territories, thereby having great guiding significance for operation and accuracy improvement of the electric-transmission-line mountain fire monitoring system.

The invention discloses a method for measuring the threshold value of stress intensity factor of type II cracks in metal materials. The left end of the sample is fixed by a sample fixing mechanism, the right end is provided with a horizontal gap extending from the right end to the center, and the inner end of the gap is provided with a tip facing the right end The triangular crack initiation and expansion part of the surface, and the vertical edge at the tip is provided with a V-shaped notch, and a support rod is inserted into the gap; between the upper clamping part and the upper cantilever of the clamping mechanism package and the lower clamping part and There are stress conducting rods between the lower cantilevers. The fatigue testing machine applies a reciprocating load through the upper cylinder on the upper part of the upper clamping part. After the test, cut the sample perpendicular to the end face, observe the type II crack, and calculate the type II The magnitude of the stress intensity factor corresponding to the critical length of the crack is the threshold value of the stress intensity factor for the type II crack of the metal material. The invention is beneficial to ensure the initiation of cracks on the neutral plane, to ensure that the shear stress decreases with the increase of the crack length, and to ensure the stable expansion of the cracks along the neutral plane of the sample.

The invention discloses a main bearing beam for a large wind power blade. The main bearing beam is a carbon fiber / glass fiber mixed composite material round bar sectional material combined body, and the combined body is formed through beam bunching and sizing of a plurality of carbon fiber / glass fiber mixed composite material round bar sectional materials via glass fiber felt or yarn. According tothe main bearing beam for the large wind power blade, the combined body is formed through beam bunching of the carbon fiber / glass fiber mixed composite material round bar sectional materials, complementation of carbon fiber performance and glass fiber performance is sufficiently utilized, the beneficial effects of high elasticity and lightness of carbon fiber are brought into sufficient play, therigidity and strength of the main bearing beam are greatly improved, and the critical length of the main bearing beam is increased; meanwhile, the price is greatly reduced compared with the cost of adoption of pure carbon fiber serving as reinforcing materials, and popularization and application of the carbon fiber to the field of the main bearing beam and the wind power blade are better facilitated. The invention further correspondingly provides a mixed spar composite material wind power blade and a preparing method of the mixed spar composite material wind power blade.

The invention discloses a large-scale composite material wind-power blade which comprises a suction face shell (1), a pressure face shell (2) and a cutting webplate (3) fixedly connected between the two shells, wherein the suction face shell (1) and the pressure face shell (2) are both sandwich type structural parts of an envelope (4) for covering a core material; the core material comprises a main blade bearing beam (5), a flange reinforcement part (6) of the blade and a filling material (7) arranged between the main blade bearing beam (5) and the reinforcement part (6); and the main blade bearing beam (5) and the reinforcement part (6) both use mixtures of carbon fibers / glass fibers as an reinforcement material. The large-scale composite material wind-power blade has the advantages of light weight, extended critical length, excellent mechanical property, and the like.