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Aiming at the mechanical properties of plow head and dynamic charateristics of system under oblique cutting condition,cutting resistance of planning tool under oblique cutting condition was derived,and was treated as external excitation. Dynamic differential equation of plow system were established by using the finite element method,and were solved by using numerical method. The effect of oblique cutting velocity、cutting depth、cutting location、middle trough angle offset on dynamic charateristics of plow system. The dynamic charateristics of plow system were tested based on the mechanical test experimental platform. The test results and theoretical results were compared. The research results provided theoretical basis for working stability、fatigue life of key parts、process parameters optimization of plow system.

In order to study the crushing process and its influencing factors of the coal rock ploughing and planing by the plough cutters,the planing process is analyzed by numerical simulation, in view of the fact that coal and rock are heterogeneous media, coal rock images are identified, the three-dimensional model of coal rock is established by image reconstruction method, the accuracy of simulation is increased, it provides a new theory and method for three-dimensional finite element modeling of heterogeneous materials, and obtains more accurate simulation data. Through the simulation of coal crushing process under different conditions of plow bit,get contact force plow bit and simulation of coal wall. The results show that:with the increase of planing depth, plow bit stress force increase, the stress gradually stabilized,but because of the change of the coal quality, the forces fluctuate up and down near a steady value;planing speed has little effect on the plane load;coal rock firmness coefficient is larger,the greater the load simulation tool.

In order to study the cutting energy consumption characteristics of coal miner under complicated conditions, the MG500/1180-WD shearer was cut out under different working conditions by collecting the cutting energy consumption model of coal mining machine. Pin and idler axle load data, and finally through the different conditions of coal miners cutting energy consumption calculation, the following conclusions: to keep the other conditions remain unchanged, the linear cutting energy consumption with With the increase of the traction speed increase; the oblique cut cutting energy consumption value is far more than the straight cutting energy consumption value; shearer cutting energy consumption in addition to the speed of traction, cutting mode, but also by the impact of coal hardness, With the increase in the hardness of coal and cutting cutting energy consumption also increased. The results of this study provide the theoretical basis for the development and use of shearer, and provide the theoretical basis for the scientific and efficient production of coal mining industry.

In view of problems of large impact of coal plow system under starting and braking condition，dynamic model of the coal plow system was established comprehensively considering factors of sprocket wheel polygon effect, horizontal vibration of drive sprocket shaft, and coupling characteristics between driving device and plow chain. Dynamic characteristics of the system under condition of starting, braking and reverse starting after braking were analyzed by numerical analysis method, and vibration characteristics curves of the front and rear chain tension were obtained. The analysis results show that the system dynamic characteristic are the most stationary by using reverse 'S' start scheme, the method is more advantageous to the coal plow system; the nearer the distance between the plow head and the machine head is，the larger plow chain tension impact is; due to time difference between nose and tail of the machine, tension in the front and back end of the chain has a great impact in the starting process; the plow chain tensions produce difference because of uneven distribution after the coal plow system barking，the plow chain tension of the front end has great impact at the reverse restart moment, and it falls with the starting process. The research results provide theoretical basis for designing reasonable start and brake system of the coal plow.

In order to study the effect of coal properties on the plow planing cutter load characteristics in the process of coal plough testing by using the self-developed real-time sensor for testing on two planes load properties of coal or rock under,through the wireless acquisition module to collect the test data,get the planer load data curve and carries on the analysis and research on the fractal characteristics of the wavelet. The results show that with the increase of hardness of coal rock,planing force increases gradually,the plough vertical planer X direction,the maximum value of the curve is 35. 642 kN,in the Y direction perpendicular to coal wall,just contact the coal wall produces an instantaneous pulse,reached the minimum value of-19. 831 kN in this curve,in the Z direction along the planer operation,the maximum value is 20. 419 kN; the fractal dimension of load was about1. 5. The fractal dimension in three directions with a coal nature difference,coal load curve fluctuation with lower hardness is more obvious,to reduce the consumption of coal plow cutting coal seam in the process of energy,the smaller the shape factor is better. The results for the properties of coal and rock identification provide a new point of view,to provide data support for the design and optimization of coal plough parts.

In order to study on the loading spectrum and fatigue life of hydraulic tension bars on shears,this paper solves the spatial mechanic problems of hydraulic tension bars by constructing spatial mechanical model and using partitioned matrix element segmentation method. Using experiment to test the operating load of hydraulic tension bars,this paper chooses the worst loaded one to simulate the fatigue life. The result indicates that the stress concentration part of hydraulic tension bar locates on the root of the first screw thread. The maximum stress point is close to the end point at the root of the first thread tooth,of which the number is 1386 MPa,the triple thread teeth bear over 50% of the full load; the position on which fatigue crack occurs first is at the root of the thread teeth in the screw part of the hydraulic tension bar; assuming that the daily continuously working time for shear is 12 hours,the hydraulic tension bar starts to crack at the 53 rdday. This research provides load data for hydraulic tension bar structural design,and also offers a new method of operating load monitor for shears.

In order to study the mechanical and load properties of idler shaft on rocker arm shearer under complicated conditions,used the shaft sensor to test the load of idler shaft on rocker arm under different conditions,and through the wireless module to store and transmit the real-time data,with some test data curves in Z and Y direction obtained. The analysis results show that the load of idler shaft is the largest when coal winning machine under the oblique cutting condition,the largest load of 33. 38 kN in Z direction,the largest load of 35. 60 kN in Y direction,and thoughtout the process,the load in Y direction always larger than Z direction. The results of the study provide a new way for the idler shaft load test and data support for the coal-rock identification method and the fault monitoring on rocker arm shearer,also has important guiding and significance for coal winning machine parts design and optimization.

For the study of coal winning machine end plate load characteristic of cutting pick,with MG500 type coal winning machine roller as the research object,USES the nonlinear dynamics simulation software ls-dyna screw drum of shearer and the finite element model of coal and rock was cut,the model was used to study the working condition of oblique bottom plate and mechanical characteristics of cutting pick load characteristics changing with the installation parameters. Research shows that:the oblique cut into the cutting process,the end plate cutting pick cutting resistance and cutting resistance moment with end plate cutter tooth circumferential tangential decreases with the increasing of the installation Angle,with the side plate cutter pick intercept increases; The eigenvalues of the drum cutting resistance moment with the increase of the circumferential tangential installation Angle of the decreasing trend with the slow,along with the increase of intercept its increasing trend also increases;For the roller with good cutting performance,end plate cutter tooth appropriate chooses the larger circumferential tangential installation Angle and low intercept.

In order to study the mechanical properties of scraper conveyor chain under complicated conditions,the scraper conveyor chain tension changes during the operation of on-line monitoring was realized,The wireless transceiver module and storage testing data signal,export to stay after the test data and analysis were carried out. Experimental results showed that the same round link chain of two straight tension appeared the obvious unequal phenomenon; Coal winning machine cutting coal,increased near the coal mining is bigger than the lateral side chain tension goaf side chain tension. Image shows that whenever the chain after a sprocket will produce a Zhang Lijie leap mutation,half the no-load operation cycle time interval of 51 s,scraper conveyor motion resistance of 16 kN no-load current end,chain tension value is 896 k N. The results of the study provides theory basis for design and optimization of the chain.

According to studying Angle cutting conditions of shearer drum cutting teeth distribution on the influence law of load spectrum,which provides reference for the design of the cutter tooth,in which equivalent test tooth holder to roll the same spiral blades cut line cut tooth load the real-time online monitoring,synchronous export analysis after storage.Experimental results show that the system is reliable,stable performance,can real-time dynamic testing of cutter tooth cutting force changes,through different cut line cut tooth time-cutting force change curves available:cutting force curve variation rule has the similarity,oblique cutting coal and rock,drum cutting tooth load whole curve peaks and troughs alternating form,cutting teeth with different cutting depth change of cutting force changing process;Same cutting resistance of greater than its feeding resistance,but its fluctuations are similar,have many irregular fluctuations;Single pick on the cutting resistance and traction resistance of instantaneous value obey the symmetry good Gamma distribution,the distribution parameters with pick in the cutting line spacing end plate distance relationship is a Fourier series,for the research on the rules of cutter tooth load spectrum provides a new method.

Coal is the important basic energy in China,however due to the problems of conveyor belt running deviation and avultion caused by freezing adhesive turnabout roller surface,it seriously restricts with coal mine safe and efficient production in cold regions during winter and brings huge economic losses to the company,although existing solutions have a certain ease of coal freezing adhesion but can not fundamentally solve the problem. Through the freezing adhesive strength test device designed by ourselves,under conditions of- 25℃ temperature and 3h freezing time,freezing adhesive characteristic of four different materials with moisture content 40% of the coal slime were tested. Experimental studies have found that with the decrease of material waterlubricating coefficient of kinetic friction coal normal and tangential freezing adhesive strength decrease,it shows a certain linear relation,the results indicate that improving the water-lubricating performance can reduce the freezing adhesive strength,the discovery has important guiding significance to the selection and preparation of anti-freezing adhesive coating in engineering field,it deserves further explore and study.

In the tunnel construction practice, multiple buildings' tilt rate data are collected. In this study, data causality is defined to reflect the causal relation between the input and output of the building tilt rate detection data. Upon defining and calculating the data causality, a new high resilient causality detection (HiReCau) method is proposed for abnormal building tilt rate detection. A numerical case and another practical case are studied for validation purposes. The case study results show that the proposed HiReCau method can accurately detect high-causality data and low-causality data among the building tilt rate detection data and produces superior results compared with the direct adoption of a machine learning approach. Furthermore, the resilience of HiReCau is validated by investigations testing varied levels of additional low-causality data in the training dataset. Presently, HiReCau is limited to handling problems with a single output. Furthermore, only the back-propagation neural network (BPNN) is tested as the baseline model and there is also room to further expand the data size. The proposed approach is versatile and able to be adjusted to handle fault diagnosis and safety assessment problems in varied theoretical and engineering backgrounds. [ABSTRACT FROM AUTHOR]

The concept that classic waves reflected from a rotating absorbing cylinder will be amplified is analogously linked to the Penrose superradiance that may extract energy from a rotating black hole. The superradiance of acoustic waves carrying orbital angular momentum (OAM) from a sound absorber has been demonstrated in a recently published experiment using two rotating microphones. The experiment showed that the waves were amplified by up to 30% when the rotation rate of the absorber satisfied the Zel'dovich condition. Here, we proposed an experimental method to detect acoustic superradiance by static microphones. We demonstrated that the acoustic waves transmitted through a perforated absorber were amplified (by up to 1000%) even when the Zel'dovich condition was not satisfied. The experiment also showed that when the Doppler-shifted frequency of an observer was 0 Hz, the acoustic amplitude was very weak regardless of the rotation rate of the absorber. Our work was worthwhile not only in the proposed experimental method that was well-suited for observing the acoustic OAM wave but also in the high amplification achieved at a low rotation rate of the perforated absorber, showing a great prospect in practical applications such as amplifying the information-carrying OAM waves for high-speed acoustic communication. [ABSTRACT FROM AUTHOR]