33 results about "Stress estimation" patented technology

The invention aims to provide a massage apparatus and massage program for giving stress-improving massage. The massage apparatus includes: a massage unit 10, 20, 30, 40 configured to massage a user; a biological information acquisition unit 210 configured to acquire biological information of the user; a stress estimation unit 90 configured to estimate a degree of stress of the user based on the biological information acquired by the biological information acquisition unit; and an operation determination unit 70 configured to determine a massage operation to be performed for the user by the massage unit based on the degree of stress of the user estimated by the stress estimation unit.

A method and system for estimating reservoir pressure in a hydrocarbon reservoir from downhole pressure measurements of producing wells is disclosed. Pressure measurements are obtained from wells in the production field over time, and communicated to a server that applies the pressure measurements for a well to a model of that well. The server operates the model using the pressure measurements to determine an operating mode of the well, such as producing or shut-in. Upon detection of a change in operating mode indicative of an abrupt change in flow at the well, such as corresponding to a shut-in event, additional downhole pressure measurement data is acquired until a steady-state condition is reached. The pressure measurements are used to determine a reservoir pressure, which is transmitted to a responsible reservoir engineer or other user. Modification of the determined reservoir pressure value by the user can be received, and the stored reservoir pressure and well model are updated accordingly.

The invention provides a foundation temperature difference stress estimation method and an upper-lower layer temperature difference stress estimation method for mass concrete. Each of a foundation temperature difference stress and an upper-lower layer temperature different stress is comprehensively estimated according to multiple factors such as a maximum concrete temperature, a concrete elasticity modulus, a pouring block length, a basic elasticity modulus and a water cooling condition, for example, a first stage and a second stage are watered for cooling, or the first stage is watered for cooling or not watered for cooling. A typical concrete thermodynamic parameter summarized by an academician Bofang Zhu and a common water cooling measure generally used in engineering are used, and a finite element computing method is used for verifying estimation results. Compared with existing estimation methods, the methods provided by the invention can achieve more accurate and reasonable estimation results, and can be applied to actual engineering for scientifically guiding engineering practice and improving engineering quality.

The invention discloses a ground stress evaluation method based on well wall mechanical instability and collapse, including mechanical instability and collapse well section screening and data classification, expressing deep ground stress and well wall stress based on structural strain coefficient, and based on stress limit balance Establish the structural strain coefficient equation based on the least squares method, calculate the horizontal principal stress, and evaluate the rationality of the estimation results of the ground stress; the present invention constructs strain-based The stress limit equilibrium equation of the coefficient and the solution of the overdetermined equation based on the critical collapse formation information constraints are used to calculate and evaluate the deep in situ horizontal maximum principal stress and minimum principal stress, and give the rationality evaluation method of the in situ stress results, realizing the deep Quantitative calculation and evaluation of formation horizontal principal stress provides necessary basic parameters of deep formation mechanics for underground deep engineering, especially oil and gas well engineering and oil and gas exploitation engineering.

The invention relates to a method for estimating hot spot stress of an ocean floating platform based on a response surface model, comprising: step S1: establishing a response surface model of the hot spot stress of the structure of the ocean floating platform, according to the nonlinear influence of the hot spot stress of the structure of the ocean floating platform , introduce control parameters; Step S2: establish a numerical model for stress analysis of the marine floating platform, change the values ​​of the influencing factors through numerical calculation methods, obtain the hot spot stress under the corresponding conditions, and use regression equations to fit the relationship between the hot spot stress and each factor , determine the corresponding coefficients of the control parameters, and establish the hot spot stress calculation formula according to the corresponding coefficients; Step S3: monitor the wave environment at the location of the ocean floating platform, select the spatial near-field measuring points of the hot spots to carry out stress monitoring, and analyze the results. Enter the formula to obtain the hot spot stress at the current sea state. Compared with the prior art, the present invention has the advantages of less error, more comprehensive monitoring data, and more authoritative calculation results.

The invention relates to a method for estimating the axial stress of long-period fiber gratings based on random forests. First, the transmission spectrum of the sample to be tested is measured through the built-up long-period fiber grating axial stress measurement experimental platform, and then the resonance wavelength characteristics of the transmission spectrum are extracted. , and finally combine the random forest algorithm to calculate the axial stress of the tested sample, and realize the effective estimation of the axial stress of the long-period fiber grating.

The invention discloses a method for estimating the stress of Barkhausen signals based on slow feature analysis. It intends to use Barkhausen signals under different stresses, extract the Barkhausen slow signals through the slow feature analysis algorithm, and then calculate the Barkhausen slow signals. Extract the eigenvalues, and finally use the obtained eigenvalues ​​to fit the stress data. Since the residual stress is an inherent property of the material itself, the slow feature analysis method has higher accuracy. It includes the following steps: Step 1: Combine the Barkhausen signals under different stresses into a vector; Step 2: Perform slow feature analysis on the combined Barkhausen signals to obtain the Barkhausen slow signals; Step 3: Extract the Barkhausen signals The upper envelope of the slow signal obtains the slow-varying characteristics of the Barkhausen signal. Step 4: After averaging the slow features of the Barkhausen slow signal, the feature vector is formed. Step 5: Regression linearly the different stresses and eigenvectors to obtain the expression model of the characteristics and stress of the Barkhausen slow signal.

The invention relates to a method for estimating the cumulative amount of electrothermal degradation of a power cable considering a random process, including determination of the daily load of the power cable, estimation of the temperature of a conductor of the power cable, determination of an electrothermal life model of the power cable, and estimation of the cumulative amount of degradation of the power cable. The determination of the daily load of the power cable includes obtaining the load curve of the power cable in a step change and the current in the cable; the temperature estimation of the power cable conductor includes obtaining the temperature distribution of the cable conductor; the determination of the electrothermal life model of the power cable includes estimating the electrical stress, Cable service life under thermal stress and the synergistic effect of the two; the estimation of the cumulative amount of power cable degradation includes calculating the cumulative amount of cable degradation over a period of time. This method can improve the accuracy of cable service life prediction.

Unconventional reservoirs need hydraulic stimulation in all the wells to enhance permeability for an economic production, which accounts for a large part of the well expenditure. However, lack of accurate stress information leads to incorrect selection of producing intervals, which transforms to under-performance in production. An analytical solution is optimized to determine the principal horizontal stresses by integrating the concept of uniaxial elasticity and frictional equilibrium. The software tool allows estimation of the continuous solutions of stresses based on the frictional strength concept. A more realistic considerations of rock rheology in stress estimation and better estimate principal horizontal stress magnitude in the earth crust help in planning and executing hydraulic stimulation operation. The stress estimate also aids in planning important parameters to drill and complete the wells successfully.

The invention provides a bridge stress early estimation method, which comprises the following steps of: determining a plurality of effective grids on the lower surface of a bridge, and arranging a stress sensor on each effective grid to form a sensor matrix corresponding to the effective grid; for any effective grid, executing the following steps: acquiring stress data acquired by a sensor matrixcorresponding to the effective grid, wherein each piece of stress data comprises the position of a sensor for collecting the stress data; transmitting the stress data to an estimation model corresponding to the effective grid; and obtaining a stress estimation result output by the estimation model, wherein the stress estimation result is used for prompting the estimated stress at the position of the sensor of the stress data. According to the invention, the labor cost is remarkably saved.

The invention provides a bridge stress detection system, which comprises a stress detection server, a bridge detection management terminal and a sensor network, and is characterized in that the sensornetwork comprises a plurality of effective grids, and each effective grid is provided with a stress sensor to form a sensor matrix corresponding to the effective grid; the stress detection server comprises a management module and a stress estimation module, the stress estimation module comprises a plurality of estimation models, a bijection relation exists between each estimation model and a corresponding effective grid, and the estimation models only acquire data acquired by stress sensors in a range corresponding to the effective grids and output estimation results; and the bridge detectionmanagement terminal is used for interacting with the management module, issuing a management instruction to the management module and receiving push information sent by the management module. According to the invention, the detection efficiency is improved.

The invention relates to the technical field of stress estimation of prestressed anchor cables, and discloses a method for estimating the stress of prestressed anchor cables, including an anchor gauge and a jack. Load P max =ψF s , F s In order to design the locked load, ψ is the overtension coefficient; (2), the prestressed anchor cable installation clamp, the prestressed anchor cable is normally stretched to P max , record the readings of the anchor force gauge, and calculate the pressure value M according to the side school equation max ; (3), the jack retracts and releases the tension, the clip is self-locking, records the reading of the anchor force meter after locking, and calculates the pressure value M according to the side school equation 0 ; (4), calculate ψ according to the formula; (5), check the next batch M 0 with F s If the difference is more than 5%, then adjust ψ, and so on. Through the cooperation of the jack and the anchor force meter, the stability of the indication value of the jack and the full-range monitoring of the anchor force meter can be used to understand the stress of all prestressed anchor cables more comprehensively and accurately, and improve the accuracy of stress estimation of prestressed anchor cables.