Abstract: A cast iron brake caliper with improved fatigue life, and a process and process equipment for pre-stressing a cast iron brake caliper to provide improved fatigue life, is provided. In the process, a load is applied to a cast iron caliper, where the load is high enough to locally yield and plastically deform the cast iron material, but not high enough to cause material failure, such as cracking. Upon load removal, residual compressive stresses in the cast iron caliper lower the mid-point of the stress range the plastically-deformed region of the caliper sees during in-service use, and thereby lowers the peak stress seen in this region, increasing fatigue life. The process permits a cast iron brake caliper to be designed to use less material and thus fit within constrained wheel rim envelopes, without the need to resort to high cost materials or other alternative design strategies.

Abstract: Provided is a method for rapidly, surely, and easily identifying a factor of a shape defect of an artifact attributed to elastic recovery of deformation upon molding by using the numeric value simulation technique, thereby eliminating lowering of dimension accuracy.

Abstract: Apparatus and methods for measuring a dynamic deformation characteristic of a deformable target surface during a deformation interval. The measurement principles may be applied to a large variety of organic and inorganic materials having a surface that can be deformed by an applied non-contact force. The surface may be light diffusing and non-transparent or non-diffusing and transparent. A device for measuring a dynamic deformation characteristic of an in-vivo cornea during a deformation interval includes a corneal topographer and an air puff generator that are operationally integrated. Use of the inventive device enables a method for making a measurement of a deformation characteristic of the in-vivo cornea during a deformation interval, further allowing a determination of spatially-resolved in-vivo corneal biomechanical and biodynamic properties such as corneal elasticity and corneal viscosity.

Abstract: A method and system determines probable strength degradation in a tensile support in an elevator system by monitoring an electrical characteristic of the tensile support as a whole, such as the total electrical resistance of the tensile support, that varies as the remaining strength in the tensile support varies. One example system determines a relationship between strength degradation and various physical factors, such as the rate of degradation for a given load (102), operating environment information for the tensile support (104), and estimated usage data (106), to obtain a map of mean degradation (100). This map of mean degradation (100) is then used to generate one or more maps linking the strength degradation and electrical characteristic.

Abstract: Systems and methods for determining one or more characteristics of a specimen using radiation in the terahertz range are provided. One system includes an illumination subsystem configured to illuminate the specimen with radiation. The system also includes a detection subsystem configured to detect radiation propagating from the specimen in response to illumination of the specimen and to generate output responsive to the detected radiation. The detected radiation includes radiation in the terahertz range. In addition, the system includes a processor configured to determine the one or more characteristics of the specimen using the output.

Abstract: In computing the overall material constant of a composite material, a virtual composite material is defined as the one that predetermined material components are dispersed in a form of spherical particles in a matrix phase at known volume fractions, and a nonlinear equation having the overall material constant of the virtual composite material as an unknown is prepared. Next, the overall material constant of the composite material is computed by solving the nonlinear equation. The nonlinear equation is a recursive nonlinear equation which is obtained by defining the material constant in the surrounding areas of the spherical particles as the overall material constant of the composite material to be computed. The volume fraction of a material component dispersed in the composite material is computed using the recursive nonlinear equation.

Abstract: A method and system for relieving forging induced residual stresses in a rotor forging balances a pre-spin machine with the forging mounted thereon at a first rotational speed and then pre-spins the forging with it mounted on the machine at a substantially greater second rotational speed. A one per rev sensor is used for determining a weight placement angle and a vibration sensor is used for determining an amount of weight to add to a spinning assembly including the forging during the balancing. High-density non-metallic balance weights adhesively attached on an inside surface of the forging or spinning assembly may be used. The rotational inertia of the spinning assembly may be checked during a spin up period by determining a rate of rotational acceleration vs. torque applied to the spinning assembly and used to stop the pre-spinning if it is to great.

Abstract: In a method for use of x-ray diffraction to measure the strain on the top silicon germanium layer of an SOI substrate, the location of the peak diffraction area of an upper silicon layer of the SOI substrate is determined by first determining the peak diffraction area of the upper silicon layer on a reference pad (where the SOI thickness is about 700-900 Angstroms) within a die formed on a semiconductor wafer.

Abstract: An analyzing method includes acquiring displacements with respect to loads applied of the test piece measured by the three-point bending test; calculating a first approximate expression of a relation of the displacements with respect to the loads applied in a first area where the relation is linear so as to determine an elasticity modulus of the test piece; extracting boundary value of a relation of strains caused by the displacements with respect to the loads so as to determine a yield stress value of the test piece; and calculating a second approximate expression of a relation of stress caused by the loads with respect to the strains caused by the displacements in a second area beyond the yield stress value on the basis of the yield stress value, the elasticity modulus, and the measurements in the second area.

Abstract: A stress analysis method uses a thermoelastic stress measurement device to measure measuring stress state acting on an object by measuring material temperature state variation caused by stress, a mechanoluminescence measurement device to measure measuring stress state acting on the object by measuring light emitted from mechanoluminescence material according to the stress and an arithmetic processing device to obtain mechanical information, which includes prescribed stress distribution, by performing arithmetic processing on both the measurement data.

Abstract: The present invention provides a unit cell durability evaluation method for evaluating a unit cell of a fuel cell including a polymer electrolyte membrane, two plate-like electrodes installed on both sides of the polymer electrolyte membrane, two plate-like separators having groove-like gas channels for supplying gases to the electrodes, and a seal component for sealing side faces of the electrodes, in a information-processing equipment, and the method involves a reception step (S01), a model production step (S02, S03), a water distribution calculation step (S04), a strain/stress calculation step (S05), an equivalent stress calculation step (S06), an evaluation value lead-out step (S07, S08), and an output step (S09).

Abstract: A pin bearing arrangement for use on an aircraft landing gear includes a pin and a load sensor arrangement, which may include strain gauges for measuring shear loads and accelerometers for measuring loads sustained by the pin. The pin includes a self-contained data logging device for logging data concerning loads sustained by the pin. Thus, inside the pin, there may be provided a processing unit, a memory store, and a battery-based power source. During normal operation of the aircraft fatigue loads may be monitored, the processing unit receiving input signals from the means for measuring loads and storing load data in the memory. The stored load data may periodically be extracted from the memory during maintenance of the aircraft.

Abstract: A system includes a structure and a circuit. The circuit is mounted to the structure. The circuit includes a sensor, a non-volatile memory, and a voltage sensitive switch. The memory and the voltage sensitive switch are connected for recording an event sensed by said sensor. The recording only uses power derived from the sensor. One embodiment of the circuit includes a processor connected for receiving a signal derived from the sensor. In this embodiment the non-volatile memory is connected to the processor for receiving and storing data derived from the signal. In one embodiment a first energy storage device is connected to receive energy from the sensor. The voltage sensitive switch is connected for releasing energy from the first energy storage device when energy stored in the first energy storage device exceeds a threshold. The processor and the non-volatile memory are connected for receiving power from the released energy.

Abstract: The present disclosure is directed to a computer-implemented method for modeling a mounting assembly having a mounting strap configured to couple a component to a bracket. The method includes modeling a loosened configuration of the mounting strap, wherein the loosened configuration provides a first substantially continuous curvature of portions of the mounting strap engaged with the bracket and the component. The method also includes applying simulated stresses to the mounting strap in the loosened configuration and outputting failure mode information of the mounting strap based on the simulated stresses on the mounting strap.

Abstract: A method of maintaining a structure includes providing a structure having a component subject to failure. A sensor, a memory and an energy harvesting device are mounted on the structure. The sensor is used and data derived from the sensor logged in the memory, wherein the memory is powered solely with energy derived from the energy harvesting device. The component is replaced if information in the memory shows that the component was subject to damaging usage.

Abstract: When discretizing an analysis target part into plural elements and performing analysis, sheet thickness reduction rate or maximum principal strain at an equivalent position including a same element is compared by either a manner of combining two adjacent elements after the analysis or a manner of changing an element discretization size with two types and performing the analysis, and the element where the difference is large is extracted as a fracture risk portion. With this structure, a fracture risk portion can be extracted reliably when a fracture is predicted by a finite element method.

Abstract: The invention is an improved process for using surface strain data to obtain real-time, operational loads data for complex structures that significantly reduces the time and cost versus current methods.

Abstract: Methods, program products, and computer systems for estimating a stress of a toughened structural adhesive polymer are provided. One method comprises selecting a strain, a strain rate, a temperature, or a combination thereof at which the stress is to be estimated. A value of a strain-hardening stress of the toughened structural adhesive polymer is determined, wherein the value of the strain-hardening stress is dependent on the temperature and the strain. A value of a non-strain-hardening stress of the toughened structural adhesive polymer is determined, wherein the value of the non-strain-hardening stress is dependent on the strain, the strain rate, and the temperature. The value of the strain-hardening stress is added to the value of the non-strain-hardening stress to obtain an estimated total stress.

Abstract: A monitoring system is provided, which may include a structural component configured to undergo mechanical loading and a wireless node attached to the structural component. The node may include a strain sensing device configured to measure strain experienced by the structural component at the location of the node. The node may also include a processor configured to predict, based on the strain measurements, fatigue life of the structural component.

Abstract: A system measures the strain of an object. The system includes a laser source for generating an output radiation, a strainable optical fiber having first and second facets, and means for calculating a measure of a strain of the optical fiber. The first facet is coupled to the laser source for receiving the output radiation and for transmitting therefrom a guided radiation over the optical fiber towards the second facet. The second facet is adapted to receive the guided radiation and to reflect a corresponding reflected radiation towards the first facet. The laser source is a self-mixing type adapted to receive at least part of the reflected radiation and to mix the output radiation with the received radiation. The calculating means calculate the measure of the strain of the optical fiber through the linear displacement of the second section measured by the self-mixing effect in the laser source.

Abstract: System, computer software and method for determining a susceptibility to reheat cracking of a sample of material, which includes a welded area. The method includes measuring a length of the sample, applying a first stress to the sample to achieve a predetermined elongation of the sample, exposing the elongated sample to a predefined heat treatment, applying a second stress to the sample until the sample breaks at least into two different pieces, and determining the susceptibility of the broken sample to reheat cracking.

Abstract: This invention provides a method and device for imposing and determining mechanical stress and/or strain, on micro-scale and nano-scale beams, films or multi-layers of materials such as metallic materials, polymer materials, ceramic materials, carbon-based materials and silicon-based materials using a set of micro- or nano-machines. The present invention also provides methods to derive and modify various properties or state of such nano- or microstructures, among others mechanical properties, and to measure the external stimulus that they are subjected to.

Abstract: The distributive elastic properties in nonlinear structures is characterized using an inverse elastostatic approach of stress analysis using assumed elastic models without knowing the realistic material parameters. Stress distributions are computed independently of strain measurements. A database of pointwise stress and strain data in regions of the nonlinear structure permits the elastic properties of the structure to be characterized point-by-point to provide the property distribution.

Abstract: A method of measuring a stress component in a short period of time in a nondestructive manner and a stress component measurement device that includes a stress component comparison section that compares a Raman spectrum L obtained in a predetermined area W1 of a reference specimen W to which a given stress component is applied with the stress component, a correlation data production section that produces correlation data indicating a correlation between the Raman spectrum L and the stress component by the use of a multivariate analysis method based on the comparison results conducted by the stress component comparison section. The comparison is conducted multiple times on different predetermined areas W1.

Abstract: A method for estimating the magnitude of a back-and-forth-direction force exerted on a tire comprises: using a plurality of strain sensors fixed to a tire sidewall capable of outputting data on the magnitude of a strain occurred at the position of the strain sensor; reading the output data from the strain sensors when come to fixed measuring positions predetermined around the tire rotational axis; in relation to each of the strain sensors at the respective measuring positions, calculating the back-and-forth-direction force as an intermediate result by the use of the data read from the strain sensor and a relational expression, whereby the intermediate results are obtained from the respective strain sensors; and computing a mean value of only the valid intermediate result(s) so as to output it as the estimated magnitude of the force.

Abstract: There is disclosed a monitoring system for monitoring alignment of a piston rod assembly of a reciprocating pump, such as those used to pump drilling mud in the oil and gas exploration and production industry. In one embodiment, a monitoring system is disclosed which is for a reciprocating pump (10) of a type comprising a fluid end component (20), a power end component (18), and a piston rod assembly (12) extending between the fluid and power end components. The monitoring system includes a number of sensors (52, 74) coupled to the piston rod assembly, for providing an output indicative that the piston rod assembly is experiencing bending stress, which occurs in the event that the piston rod assembly becomes misaligned, in use of the pump.

Abstract: A method for detection and quantitative evaluation of a balance error occurring in a component-bearing system. Static and dynamic forces acting upon the bearing are determined by sensors of a measuring bridge, which are disposed on a rolling bearing and which change the inherent electrical resistance according to the applied pressure, and are made available for analysis in a computer in the form of a periodic test signal that is common to both forces. In order to analyze the test signal, the weighted average of the modulation frequency generated by a balance error and the weighted mean variance thereof are determined from the test signal. The variance is then compared with a given variance threshold value. A variance lying below the variance threshold value is considered to be an indication of a significant balance error in the bearing.

Abstract: The invention is directed toward a new method for estimating and imaging the spatial and temporal mechanical behavior of materials in responses to a mechanical stimulus. This method is designed to work in inherently noisy applications, such as the imaging of the time-dependent mechanical behavior of biological tissues in vivo and using a preferred hand-held configuration of scanning.

Abstract: A method of monitoring the performance of a wind turbine (1) uses bending moment data from strain sensors (4) in the turbine blades (2) to calculate rotational speed of the turbine (1), angular position of the turbine blades (2), drive torque and resultant load on the rotor (3). The method has the advantage that the inputs to the drive train of the wind turbine can be (5) measure directly.

Abstract: The present invention relates to a device that simulates the conditions causing the aging of polymeric material used in agricultural environments in order to obtain information about the rate of degradation of the material. For this purpose, the device of the invention exposes a test specimen of polymeric material to radiation, temperature, mechanical stress, humidity, etc. conditions and checks the effect produced in the material.

Abstract: A two-dimensional matrix code containing dark and light square data modules, and a finder pattern of two bars of alternating dark and light square data modules on the perimeter of the symbol for indicating both orientation and printing density of the symbol, wherein all of the data modules are the same dimension and data is encoded based on the absolute position of the dark modules within the matrix. In a first embodiment inner and outer solid bars are provided along the base and right-hand side of the matrix code symbol, the inner and outer solid bars each having a width equal to the square data modules, the inner solid bar being light and the outer solid bar being dark. In a second embodiment, an inner solid bar and an outer encoding bar are provided along the base and right-hand side of the matrix code symbol.

Abstract: A method, test circuit and test system provide measurements to accurately characterize threshold voltage changes due to negative bias temperature instability (NBTI) and positive bias temperature instability (PBTI). Both the bias temperature instability recovery profile and/or the bias temperature shifts due to rapid repetitions of stress application can be studied. In order to provide accurate measurements when stresses are applied at intervals on the order of tens of nanoseconds while avoiding unwanted recovery, and/or to achieve recovery profile sampling resolutions in the nanosecond range, multiple delay or ring oscillator frequency measurements are made using a delay line that is formed from delay elements that have delay variation substantially caused only by NBTI or PBTI effects. Devices in the delay elements are stressed, and then the delay line/ring oscillator is operated to measure a threshold voltage change for one or more measurement periods on the order of nanoseconds.

Abstract: A method for characterizing thermomechanical properties of an organic substrate includes the steps of: receiving an image of the substrate, the image including a geometric description of the circuit layers of the substrate; selecting a given one of the circuit layers for processing; converting the image to a 2-D FEM image of the given circuit layer; repeating the steps of selecting a given one of the circuit layers and converting the image to a 2-D FEM image of the selected layer until all of the layers have been processed; combining all of the 2-D FEM images corresponding to the layers to form a 3-D FEM image representing at least a portion of the substrate; determining a coefficient of thermal expansion (CTE), modulus and/or Poisson's ratio of the 3-D FEM image; and constructing a 3-D representation of the substrate as a function of the CTE, modulus and/or Poisson's ratio of the 3-D FEM image.

Abstract: A method of analyzing a finite element model of an airfoil assembly. The airfoil assembly comprises a main airfoil element and a plurality of control surfaces. The method comprises: generating a loads interface model of the airfoil assembly comprising: data which defines the spatial positions of a set of nodes, and data which associates each node with either the main element or one of the control surfaces. Load data is generated which defines loads acting on the nodes of the loads interface model, and mapped onto a finite element model to produce a loaded finite element model. A stress analysis is then performed on the loaded finite element model, and the finite element model can be refined as a result of the stress analysis.

Abstract: A binary code symbol for non-linear strain measurement that can be constructed in any geometric shape having a solid, continuous perimeter containing straight line segments. The symbol includes finder cells to “orient” the symbol in order to associate strain measurements with physical dimensions; and contains encoded data in “data regions” and/or “utility regions.” The data and utility regions can be distinct and separate, combined, exclusive (i.e. data regions and no utility regions, or utility regions and no data regions), or omitted. The data “density” can be varied depending upon the application, by varying the number of distinct data or utility cells present in the data regions or utility regions.

Abstract: A wheelchair lift having a logic module which provides several interlocks that promote proper operation is described. The logic module may be programmed to enable efficient user interface and to compensate for variations in lift operation parameters. In one embodiment, the wheelchair lift has an arm geometry which requires a lower peak force for operation.

Abstract: The invention relates to a method for the evaluation of measured values for the recognition of defect conditions due to material fatigue on aircraft parts, in which strain sensors (6) are applied on the critical locations of an aircraft (1) or the parts thereof, wherein the measured values of the strain sensors at different loading conditions are detected, amplified and stored through several measuring circuits and from which an evaluating apparatus (9) derives, signals or indicates a material fatigue by comparison of current measured values with previous measured values.

Abstract: A binary code symbol for non-linear strain measurement designed specifically for perimeter-based deformation and strain analysis. The symbol is rectangular with a continuous outer perimeter, two data regions along adjacent sides of the rectangle and a utility region adjacent each side opposite the data regions. Each data region is made up of at least two rows, each of which is made up of a number of data cells, and each utility region is made up of at least two rows, each of which is made up of utility cells with alternating appearance. There are at least two distinct finder cells on opposite corners of the rectangle, which can be used to orient the symbol. A non-linear strain gage for measuring the strain on an object under load in accordance includes a target, a sensor, and a computer, wherein the target is a binary code symbol.

Abstract: In this tyre managing apparatus, with regard to respective tyres, the back-and-forth force and the lateral force which are added to each of tyres are calculated based on the distances which are distance between each tyre and the center of gravity in the back-and-forth direction, the inertia moment of the vehicle, the vehicle weight of the vehicle, and the loads added to each of the tyres, which are as specification data of the vehicle, and based on the longitudinal acceleration, the lateral acceleration, and the yew angle acceleration, which are as state quantities of the vehicle. Also, the calculated results are memorized in the transponders of corresponding tyres.

Abstract: The present invention generally relates to methods for rapidly calculating the surface displacement that results from an arbitrarily shaped load on the surface of a layered substrate. Some embodiments include sparse direct calculations of surface displacement in combination with interpolation methods for estimating surface displacement at other points. Some embodiments include methods for reducing computer time required for calculating surface displacement caused by an arbitrarily shaped load on a layered surface.

Abstract: A system for detecting the onset of structural failure in a structural element subject to a mechanical load comprises a metering array, a signal processor, and an output processor. The metering array measures physical quantities associated with the structural element. The signal processor transforms the measured physical quantities into a series of sample mode spectra, and the output processor generates output as a function of the series of sample mode spectra. Methods are also disclosed for detecting the onset of failure in a structural element subject to a mechanical load, for structural testing, and for structural health monitoring.

Abstract: A method for predicting failures in crystalline microstructures is described. Fracture stress distribution data obtained from test samples prepared according to the same manufacturing process as a contemplated device is used to characterize the strength of surfaces in a numerical stress analysis of the device. The failure probability is then calculated for surface nodes on the device. The product of all such probabilities yields the overall probability of failure of the device.

Abstract: A method for testing adhesive bond quality includes subjecting an adhesively-bonded workpiece to a known loading function. The loading function may be cyclic, linear, or nonlinear, and configured not to damage the workpiece. Response characteristics of the workpiece are measured during the loading. Measured response characteristics are compared with baseline or nominal characteristics and the adhesive bond quality is determined from the resulting comparison. A differential signal may be generated based upon the comparison of measured response and baseline characteristics and used to determine the adhesive bond quality, possibly with an algorithm. Being within the acceptable range is indicative of acceptable adhesive bond quality. The root cause of failure may be determined and a course of action based thereupon; including: localized curing, inspection, repair, and destruction. Following corrective courses of action, the workpiece may be re-tested and compared again to the baseline.

Abstract: A method of monitoring a structure, the method comprising positioning one or more strain gauges on the structure; acquiring strain data with the gauges(s); analyzing the strain data to determine whether the structure has undergone plastic deformation; and providing an output in accordance with the analysis. By analyzing the strain data to determine whether the structure has undergone plastic deformation, a more reliable determination can be made of whether the structure has experienced an excessively high transient loading event such as a hard landing of an aircraft, or the lifting of an excessive load by a crane.

Abstract: A multi-dimension detector with half bridge load cells, which includes an analog to digital converter (ADC), a plurality of half bridge load cells, a multiplexer and a central processing unit (CPU). The CPU controls the multiplexer to form a plurality of full bridge load cells by selecting either-two of the half bridge load cells and detect a plurality of measures corresponding to an object. The ADC converts analog signals corresponding to the plurality of measures into digital signals. The CPU determines all dimension values of the object according to the plurality of measures corresponding to the digital signals.

Abstract: Several methods and a system of a resistive force sensing device and method with an advanced communication interface are disclosed. An exemplary embodiment provides a force measuring device. The force measuring device includes a resistive sensor having a fixed surface and a movable surface. A spring assembly is positioned between the fixed surface and the movable surface. The spring assembly alters in height in response to a force applied perpendicular to the movable surface and causes a change in a resistance of the resistive sensor. A circuit generates a measurement of the force based on an algorithm that considers a change in the resistance of the resistive sensor. A universal serial bus (USB) interface of the circuit provides digital output of the measurement to a computing device.

Abstract: The present invention generally relates to methods to provide electrospun polymer/nanoparticle composite-fiber structures for use as lightweight, compliant, porous strain sensors for non-cyclic strain sensing. In one embodiment, the fibers in the nanocomposites comprise, for example, poly(?-caprolactone) (PCL) dielectric polymer matrix with embedded electrically conductive carbon black (CB) nanoparticles. In another embodiment, the composite-fiber structures of the present invention contain at least about 7 weight percent or more of CB and are electrically conducting in the as-spun, un-deformed state, and are thus called conductive polymer composites (CPC). In still another embodiment, the electrical resistance of a nanocomposite structure according to the invention increases with strain, and at sufficiently high strains the structure is rendered non-conductive.

Abstract: A method of detecting the formation of ice on the blades of a wind turbine 1. The wind turbine has at least one turbine blade 2 mounted to a rotor and provided with at least a first strain sensor 4 for measuring mechanical strain of the turbine blade. The method comprises detecting changes in an output signal of the strain sensor 4 due to changes in the mass of the turbine blade 2 caused by the formation of ice on the turbine blade.

Abstract: Automatic generation of a tolerance scheme includes accessing data defining a three-dimensional model that defines a part for manufacture, identifying a tolerance feature in the three-dimensional model, determining at least one unconstrained degree of control for the tolerance feature, automatically creating a tolerance scheme for the tolerance feature, and rendering the tolerance scheme and the three-dimensional model in a window such that the tolerance scheme annotates the tolerance feature. The tolerance scheme is based on an engineering standard for communicating a tolerance and constrains the unconstrained degree of control.

Abstract: A method for determining the condition of a turbine blade (2, 4) in a compressor and utilizing the collected information in an estimation of the lifetime of the turbine blade (2, 4), whereby a measured value reflecting the condition of the turbine blade (2, 4) is generated by a vibration sensitive sensor (10) connected to the compressor's (1) casing (6).