4 results about "Small strain" patented technology

This invention provides a method for testing the roller tilt angle distribution of a double-row tapered roller bearing. First, a calibration experiment is performed. At least three strain gauges are arranged equidistantly on the outer surface of the bearing outer ring corresponding to each roller in the load-bearing area. By loading a single roller, the strain response of all strain measurement points on the outer ring corresponding to each roller in the load-bearing area of ​​the test bearing is obtained. This allows for the determination of the load measurement point positions unaffected by roller tilt under different tilt directions, as well as the corresponding load transfer coefficient and roller tilt angle calibration coefficient. Then, the strain measurement points of the test bearing are rearranged. The newly arranged test bearing and test bearing housing are installed at the work site. Combined with the calibration results, the roller tilt angle distribution of the bearing in its in-situ state can be calculated. This invention uses smaller strain gauges, making installation in practical environments more convenient and allowing for easier tilt angle distribution testing. This invention can be directly installed at the work site after calibration on a simple test bench, thus having wider applicability. This invention can monitor the roller tilt state of the load-bearing area of ​​the rolling bearing online in real time.

When the hammer for small strain detection is used, the left end and the right end of the cross rod are held by two hands respectively, the hammer is lifted, the lower end of the vertical rod of the hammer abuts against the pile top of a pile foundation to be detected, one end of the pull rope is wound through the pull rope winding device, and therefore the balance weight and the knocking head are pulled to rise. The counterweight is blocked by the lower end of the first vertical hole until reaching the upper limit position and cannot continue to rise; then, one end of the pull rope is not wound through the pull rope winding device any more, the balance weight and the knocking head freely fall, and knocking is completed through the knocking head. The hammer for small strain detection can conveniently and quickly knock a pile top in a small strain experiment, so that the working efficiency is improved, the same knocking force is ensured each time, and errors are reduced.

This invention discloses a method for identifying fatigue cracks in wind turbine blades based on distributed optical fiber strain response, belonging to the field of wind power equipment condition monitoring technology. The method includes the following steps: collecting continuous optical strain response records formed during the wind turbine blade's operation; organizing these records according to a unified time scale to form a strain change trajectory; calculating the difference in amplitude between adjacent strains within the strain change trajectory and extracting continuous, slowly fluctuating segments to form a list of low-frequency oscillation segments. This invention identifies low-frequency oscillation segments in the strain change trajectory and constructs an oscillation unfolding trajectory, enabling the time unfolding of local strain changes in the low-frequency oscillation background, thereby revealing the minute strain change characteristics of the crack initiation stage; further, by extracting suspected crack fragments and reconstructing crack release trajectories, a crack strengthening trajectory is formed, allowing crack release changes to be continuously presented in a continuous time series, improving the early identification capability and the ability to identify the change process of fatigue cracks in wind turbine blades.

The invention discloses a three-dimensional crustal stress prediction method based on structure size deformation and numerical simulation. The method specifically comprises the following steps: S100, a first stage: constructing large deformation simulation; comprising the following steps: S110, establishing a three-dimensional frame model by using depth domain horizon data according to a seismic interpretation result; s120, setting a constitutive model and a strain softening mode; s130, stratum mechanical parameters are set; s140, setting a boundary condition; s150, setting speed boundary loading; s160, carrying out numerical calculation, comparing strain distribution in a simulation result with fault distribution obtained through geological exploration, and checking the correctness of a large-deformation simulation result of the structure; s200, in the second stage, small strain simulation is constructed, the simulation result in the first stage serves as an initial model, and speed boundary loading is modified into stress boundary loading; carrying out numerical calculation, and comparing stress distribution of a simulation result with an actual measurement result; according to the method, the model constraint degree is increased, and the reliability of a three-dimensional crustal stress prediction result can be improved.