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In finite element numerical simulation, the calculating results of geometrical models with different mesh density tend to have obvious differences, especially when material damage and fracture are considered. In order to study the mesh dependency of the finite element calculation, models of a projectile penetrating into the target with different mesh densities are constructed by using LS-DYNA. A nonlocal approach is investigated and the results without and with MAT_NONLOCAL are compared. It is found that the nonlocal model with a variable characteristic length parameter provides a relatively accurate and stable result, and the calculation cost can be reduced.

To reveal the anti-penetration mechanism of titanium alloys armor quantitively, the volumes of the front crater region, the ductile hole-enlargement region, as well as the back caving region of Ti-6Al-4V alloy and β20C alloy were measured via 3D Optical scanning technology. The experimental results show that β20C alloy, of which the volume fraction of ductile hole-enlargement region is 51%, 10% larger than that of Ti-6Al-4V alloy, presents a better ballistic performance. It is found that the ballistic performance is closely related to the volume of ductile hole-enlargement region and a relatively larger ductile hole is beneficial to improve the ballistic performance. However, the ballistic performance shows no improvement with increasing the volume of front crater region.

MAT224 is a tabulated version of the Johnson-Cook model in LS-DYNA. Compared with the original Johnson-Cook material, MAT224 was developed to simulate the dynamic response of a material by just defining the effective stress as a function of effective plastic strain at different strain rates and temperatures, thus avoiding the tedious parameter fitting procedures in the traditional Johnson-Cook model. However, the stability and precision of solution is strongly dependent on the effective stress versus effective strain curves in MAT224, and unreasonable curve data will lead to warnings or errors in the process of solution. In the current study, a two-dimensional axisymmetric finite element model for the Ti-6Al-4V titanium alloy under dynamic compression was built, and MAT224 was employed. By investigating the effects of the curve numbers, strain ranges, data points, as well as changing tendencies, on the simulation results, the stability and the reliability for MAT224 are systematically studied.

In order to simulate moment distribution on linings of tunnel excavated by shield, FEM-based procedure is proposed. According to geological data of tunnel excavated by shield, FEM model is performed, and the moment, axial force and shear force distributions on linings are computed. The maximum moment on segments decreases while Poisson’s ratio of soil materials touching to segments increases. The moment value and distribution vary with Young’s modulus of soil materials. The maximum positive moment on linings is approximately equal to the maximum negative moment.

Redundant Discrete Wavelet Transform (RDWT) and Wavelet Atomic Transform (WAT) are proposed in this paper as a couple of dictionaries to get the structure and texture basing on morphological component decomposition. Then, basing on the fact that the structure and texture have different characteristics, in this paper we use curvature driven diffusion model and Criminisi texture synthesis method to inpaint the structure and texture respectively. At last, compound the inpainted structure and texture and get the inpainting result. The experiment results show the new method can not only decompose the image very well, but also inpaint the image with strong and fairing edge, complete and clear texture .This method shows better results in image inpainting compared to the classical ones.

IEC61850 uses the abstract communication service interface (ACSI) and specific communication service mapping (SCSM) definition method. Most of data structure and communication service are mapping to Manufacturing Message Specification (MMS), but MMS has high abstraction, many 61850 ACSI services are mapping to one mms service [6]. At the same time there are many fuzzy definitions even mapping deviation phenomena, different vendors may have inconsistent understanding to the standard, this is harmful to the interoperability. This paper provide analysis and comparison to the 61850 ACSI services mapping to the MMS read, including GetDataValues, GetDataSetValues, GetBRCBValues and so on, and based on these, firstly gives implementation using the mms-ease lite of SISCO Company and detailed explanations of actual telegram. Our research is helpful to eliminate understanding difference and achieve interoperability. System test uses multiple popular software of different company to simulate as server, and the widely used network protocol analyzer software Omicron IEDScout is used to capture packets, the result verifies our implementation satisfy the functionality and interoperability.

A CAE analysis on the precision forging of big semimonocoque of vehicle axle was conducted based on DEFORM-3D software. It discussed effects of forging billet size and shape on the forging property and effect of forging shape on the flow law of metal materials, and analyzed equivalent stress, strain distribution and load-stroke curve during the forging process. Research results are used to optimize mold structure and technological parameters. Precision forging of big semimonocoque was verified valid by practical production.

Some problems exist in the teaching of video post-processing technique, basing on practice, this paper presents the application of case teaching method in teaching in order to improve the interest of learning. And it introduces the method of copying teaching to culture innovation ability. The teaching method is proved effective.

Being added by H3BO3 as flux, the nanosize strong green phosphor Zn2SiO4: Mn2+ was prepared by an improved sol-gel method. The structure and the morphology of the samples were examined by XRD, UV-VL spectrophotometer and SEM. The photoluminescence properties were measured by fluorescence spectrometer. Results show that, when the samples were annealed at 850°C for 2 hours, the intensity of emission spectrum of the sample is not strictly followed the monotonically increasing with the increase of Mn2+ doping concentration. It appears in a fluctuated tendency with the increase of doping concentration. In the 4% Mn2+ doping concentration and annealing temperature 950°C, the most strong green emission spectrum can be obtained. The mechanism of luminescence properties of this kind of material is analyzed.

A novel kind of poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS) composite was synthesized through chemical oxidation polymerization in the presence of fluorescent yellow GG (FYGG) as the functional co-dopant and Poly(vinyl alcohol) as the film-forming additives. The as-prepared composite was found combined with fluorescent function and electrochromic property. Film of the PEDOT/PSS-FYGG composites switches from green in the reduction state to blue-green in the oxidized state, which is different from the pure PEDOT/PSS of light blue (-0.2V) and dark blue (0.8V). Because of the big molecule of FYGG as the dopant, the response time reaching 90% of the full optical contrast of PEDOT/PSS-FYGG was 1.77s for the coloration process and 1.78s for the reverse bleach process, which is a little slower than the pure PEDOT/PSS. Additionally, PEDOT/PSS-FYGG film presents a good stability. It is shown that acid dye doping is an effective method to broaden the color change range of the electrochromic mateials.

Based on feasibility and rationality, the path of the distribution centers, cargo terminal and receiving point as the optimized object.Using the Dijkstra algorithm and to improve it,set up customer logistics cost minimum as the target of route choice model;Using the improved Dijkstra algorithm greatly improves the operation speed,especially in the cross area for the shortest path,division graph method has very big enhancement to the time complexity of the algorithm ,enable the customer logistics total cost minimum.Therefore, route choice model can accurately describe the logistics distribution problem.

Urban traffic link tunnels (UTLT) have a complex design and are a significant fire hazard. Due to the circular nature of the tunnels, smoke can easily spread through the tunnel during a fire and form a circulation loop, severely hampering safe evacuation and rescue. In this paper, the 2.8km long UTLT in Sichuan, China's Dayuan central business district (CBD) was the study subject. Fire dynamics and similarity theory were employed to perform theoretical calculations and numerical simulations targeting four different mechanical smoke extraction methods under typical fire conditions. Smoke movement was quantitatively analyzed, thus determining which of the four plans was the optimal smoke control technique: semi-transverse ventilation combined with sinking-courtyard air compensation, with ventilation beginning in the fire zone and the two flanking smoke control zones at a rate of 20 ventilations/hour. Our result provides a theoretical basis for designing and running a smoke control system in relevant projects at home and abroad, and serves as both a theoretical and a constructive practical ground for formulating regulations related to UTLT.

The accurately mathematical models, simulation models and protection algorithms of high impedance fault (HIF) on transmission lines are difficult problems. Based on the measured data and physical phenomena, a new mathematical model of HIF was presented by numerical analysis methods and MAYR’s equation. Using EMTP, the model of HIF includes a group of nonlinear time-varying resistances and a dynamic arc resistance. Based on the features of HIF under different frequency bands, this paper presents HIF comprehensive detection algorithms containing four algorithms, and analyzes the logic between each algorithm. Finally, the models and algorithms are simulated.

For the current popularity of "green building" concept, traditional architectural design teaching model is monotonous. The papers analyze the architectural design teaching problems in context of the New Times conditions. Green building concepts combine to architectural design with putting ecological ideas into the whole teaching of architectural design. The open teaching use mode "raise questions - analysis of the problem - solve the problem" to enhance learning ability. Finally, under the guidance of green building concept the results of teaching evaluation system need to reform.

The popularization of digital teaching makes the Virtual Reality-based teaching an irresistible trend of Modern Architectural Design. It can stimulate students’ learning interest and design autonomy effectively. Through a virtual experience of building space, the virtual reality-based teaching provides a different “way of seeing”, improves students’ spatial cognitive ability and pattern comprehension, enhances communication effectiveness and increases technicality of architectural design.

The electrochromic properties of an electrochemical polymerized composite consisted of poly (3,4-ethylenedioxythiophene) doped with fluorescent yellow dye (PEDOT-FY) are reported. The structures of PEDOT-FY were characterized via cycle voltammograms, spectroelectrochemistry and colorimetric analysis. Film of the PEDOT-FY composites with different FY concentrations appears multi-color changes, such as blue violet↔brillant blue, aubergine↔blue grey, magenta↔ aquamarine blue, orange-yellow↔grass-green, claybank↔moss green in the neutral state and the oxidized state respectively, which are different from the pure PEDOT of dark blue (-0.8V) and light blue (1.0V). The response time reaching 90% of the full optical contrast of PEDOT-FY was 3.4s for the oxidation process and 2.6s for the reverse reduction process when the [EDOT]/[FY] is 1:2, however, when the FY concentration decreased to [EDOT]/[FY] =1:0.01, the response time reduced to 1.9s and 1.7s for the oxidation and reduction process respectively, which is equal to that of the pure PEDOT. Additionally, the colorimetric analysis results show that components of yellow and red in PEDOT-FY films become stronger than pure PEDOT film at the whole electrochromic process. It is shown that acid dye doping is an effective method to broaden the color change range of the electrochromic mateials.

Foaming machine is a piece of important equipment in the production process of the foam concrete. This paper designed the control system with singlechip as the core of the digital processing. The communication between the singlechip and frequency converter was realized through RS485 port and the automatic control of the working process of the air compression double-bubble foaming machine can come true. The high performance-cost ratio of the single ratio enables the system control to be economical and practical; the touchscreen interface makes it simple to use; and the multi-gear setting also is easy to adjust and control. All these improve the overall performance of the foaming machine.

Multi-elements alloy with good thermal stability is expected to serve as the superheater tube material of ultra-supercritical boiler and may suffer from hot corrosion under the coal-fired atmosphere. In this study, the corrosion resistance behavior of multi-elements alloy CoCrFeNiTi0.5 coated with alkali metal sulfates at 750°C is investigated systematically. The results showed the corrosion kinetics curves of the alloy followed a parabolic growth rate. The corrosion products, which consisted of volatile Na (CrO4) (SO4), (Fe,Ni) xSy, Cr/Ti oxide as well as compound oxides with spinel structure AB2O4, were found in the oxide scale and internal attack zone of the alloy. The oxide layer had good adhesion with the matrix at the beginning of corrosion. Prolonging corrosion time, the oxide layer in thickness increased and became loose as well as porous. The micro-pores generated in the interface between the oxide scale and matrix with the occurrence of the internal oxidation and internal sulfidation. In a word, the corrosion resistance behavior of multi-elements alloy CoCrFeNiTi0.5 at 750°C can be attributed to the formation of the protective oxide layers and to the basic fluxing in molten Na4SO4 induced by low melting point eutectic.

The acoustic emission signal of pipeline leakage is characterized by nonlinear and non-stationary. It is not feasible to extract the leakage feature signal in traditional signal processing methods. The leak locations can be detected by employing the improved empirical mode decomposition (EMD) to decompose the acoustic emission signal into several intrinsic mode functions (IMF), choosing IMFs containing leakage characteristics to be reconstructed, and doing correlation analysis. Experimental results show that the positioning accuracy of leakage detection is improved obviously.

In the present work, the effect of the microstructure of AlSi6Mg2 alloy on its macro-rheological behavior of the steady AlSi6Mg2 alloy is investigated. Specifically, the effect of particle size, packing mode and degree of the agglomeration of particles are analyzed. It can be seen that the apparent viscosity decreases with increasing the particle size (d) ifdis between a few μm and 200 μm, while the solid particle size does not affect viscosity except this region. This theoretical prediction is in qualitatively agreement with the experimental data. The trend of the variation of the average agglomerate size with the particle size is the same as the one of viscosity. The packing mode of solid particles in agglomerate is closely related to the solid volume fraction and the characteristics of the alloy system. Subsequently, the state of agglomeration of solid particles which determines the rheology of semisolid AlSi6Mg2 alloy, while the external flow conditions (such as shear rate) influence the viscosity by changing the state of agglomeration. Consequently, the particle size, the packing mode and the average agglomerate size have different effect on the rheological behavior of SSMS.

Research purpose: The paper studies readjustments of land property rights which practice in the project area of Fan Zhen comprehensive land management in Taian City. According to the study make reasonable suggestions, for the similar areas of readjustments of land property rights provide experience. Research Methods: Investigating method and contrastive analysis method. Results: The right of the project area to an adjustment measures properly, and has achieved good economic benefits, social benefits and ecological benefits. Research Conclusions: Developing the new rural construction the problem from the social, economic and environmental field, effectively protect the fundamental interests of farmers to get sustainable development.

In China, water disaster often occurred in coal mines in recent years. According to official statistics on coal mine water accidents occurred in recent twelve years in China, major characteristics of the water disaster have been illustrated. The result shows that the number of both water accidents and corresponding fatalities decreased from 2001 to 2012. And apparently, the accidents occurred in township-owned coal mines and triggered by gob area water accounted for a higher proportion, respectively.

A template technology has been applied to the platform of machine olfaction. The simulation sensor array template receives field odor data or simulates the data via recorders in database, and transmits to the platform. The platform consists of several distributed monitoring subsystems based on the simulation template. Each subsystem matches a set of gas sensors array, and has functions of logging data, communicating and simulating industry application. The data from the subsystem and the preprocessed data are sent to the web server center and stored in the databases. The data has been collected, and sensor performance analyzing are performed by several layer algorithms. While the exchanging algorithms convert the field odor data to gas concentrations with ppm values, the expert systems or recognition algorithms analyze the ppm values and show the application results. All data of each layer are stored in server database systems, and each layer algorithms can been updated and saved. Finally, the supporting platform that applied to industrial monitoring systems, was developed with a kind of industrial configuration softwares, web MIS and databases, and was utilized to realize monitor to the environmental systems by the simulation template.

The shear plastic deformation behavior of a material during equal channel angular (ECA) extrusion is governed primarily by the die geometry, the material properties, and the process conditions. This paper employs the rigid-plastic finite element (FE) to investigate the plastic deformation behavior of Ti-6Al-4V titanium alloy during ECA extrusion processing. Under various ECA extrusion conditions, the FE analysis investigates the damage factor distribution, the effective stress-strain distribution, and the die load at the exit. The relative influences of the internal angle between the two die channels, the friction factors, the titanium alloy temperature and the strain rate of billet are systematically examined. In addition, the Taguchi method is employed to optimize the ECA process parameters. The simulation results confirm the effectiveness of this robust design methodology in optimizing the ECA processing of the current Ti-6Al-4V titanium alloy.

The active stokehold protective garments (ASPG) can remove body heat of ship stokehold operators working in confined and extremely hot environment via conductive heat exchange from circulating water-cooled fluid next to the skin through the body-temperature-monitoring method. Hence, portable microclimate water-cooled thermoregulation systems (MWCTS) for the ASPG have been developed by using programmable embedded system-on-chip (PSoC) in this paper. The ASPG have advantages of longer cooling periods, better temperature-controlled capability, and excellent thermal somatosensory comfort. Furthermore, they could allow users to adjust comfortable temperature and also maintain long-term constant temperature by monitoring human temperature in portable MWCTS. Additionally, optimal control algorithm may enhance system efficiency to reduce the power consumption and extend the operating time effectively; thus, the velocity and temperature closed-loop control systems have also been improved in the portable MWCTS for the ASPG. Consequently, several experiments have been implemented and explored the impact of the heat transfer rate and verified the feasibility of the MWCTS for ASPF.

Shot peening is a manufacturing process intended to give components the final shape and to introduce a compressive residual state of stress inside the material in order to increase fatigue life. The modeling and simulation of the residual stress field resulting from the shot peening process are proposed. The behaviour of the peened target material is supposed to be elastic plastic with bilinear characteristics. The results demonstrated the surface layer affected by compressive residual stresses is very thin and the peak is located on the surface.

Combined with the advantages of good protection of global robot, self-equilibrium, easy control of wheeled robot and strong obstacle surmounting ability of turbofan robot, a variable structure mobile robot which has three kinds of basic modalities of global, turbofan and three-wheel is designed. The balancing leg is retracted and the two polymorphic wheels of the robot are closed into a sphere while in the global state, and it could be conveniently threw, carried and make all directional movements on the flat grounds. When confronted with the complicated terrain environments of sand, slopes etc., the two polymorphic wheels will be outspread to the turbofan state, and the balancing leg will be opened out as a third supporting wheel so as to strengthen the ability to adapt to the environment. When the two polymorphic wheels are expanded into two wheels, the robot motions are more smoothly and easily to be controlled. A virtual prototype of the robot is designed by three-dimensional technology, as well as the motion simulation. Rationality of the mechanism design scheme of the variable structure mobile robot is verified.

The structure designing and working principle simulating of a multi-locomotion mode spherical robot which has two basic movement patterns-globule mode and three-wheel mode is proposed in this paper. When the two hemispherical shells are closed, the robot is in a globule mode, which is easy to carry, throw and achieve all directional movements on the ground. When faced with sand and slope, it can expand to a three-wheel mode, and enhance the ability to adapt to the environment. Three-dimensional technology is used for building a virtual prototype of the spherical robot, as well as the motion simulation of the spherical robot. Compared with the traditional designing and analyzing methods, the way based on three-dimensional technology is more economical, more convenient and faster.

The paper introduces life prediction models and existing questions of marine concrete structures exposed to chloride environment; Theory of Box-Jenkins time series prediction method is put forward to analyze the change law of chloride concentration of reinforcemnet surface of marine concrete structures along with time; Stationary test, model identification and parameter estimate are introduced; Modeling process and best model identification are discussed by means of analyzing laws of chloride concentration changing with time, and predicts using the best model. Analysis results show that the prediction model built by Box-Jenkins method has simple form and high prediction accuracy. Whats more, future chloride concentration can be well predicted by history values without determining specific values of durability parameters.This is a new method of life prediction of marine concrete structures.

It is essential to investigate influence factors of inversion for improving inversion quality. Firstly to classify the influencing factors, then to make numerical experiment for each influence factor using the forward and inversion simulation technology. The results show that the collection parameters and quality of echoes have the great influence on the inversion quality, and the assigned parameters of T2 spectrum inversion have little influence. Hence, optimizing the parameter of echo collection can improve the T2 spectrum inversion quality and application effect of NMR. As for the assigned parameters, they could be selected flexibly according to the concrete conditions.

A six cubic meter sound insulation chamber is designed based on the principle of double-layer wall sound insulating and porous absorption with the characteristics of stored grain insect action sound. With 3 mm thick plywood as wall material, double - layer spacing 0.08 m, the outer wall being bored, each aperture 1mm, average spacing 1.5 cm, and the hard sound-absorbing material being filled in the two layers, a quasi - double layer perforated structure is built. The ambient noise is uniformly insulated between 125Hz and 2000Hz, and the average sound insulation is about 22dB, and it meets requirements of stored grain insect action sound for the spectrum and SPL. The result shows that the sound insulation chamber has the advantages of small size, economy, and good sound insulation effects.

In order to research the effect of process parameters on temperature field evolution in laser remelting coating prepared by plasma spraying on titanium alloy surface，the finite element model of laser multi-tracks remelting temperature field was established based on ANSYS, and remelting temperature field was analyzed. The analysis results show that: under certain scanning velocity and laser spot diameter, too small laser power can't achieve metallurgical combination between coating and substrate; the effect on temperature field of scanning velocity was smaller than laser power; the influence on molten pool center temperature and remelting width of spot diameter is bigger; preheating coating and substrate can be effectively balance remelting process temperature field, thereby reducing the thermal stress and coating cracks appear chance.Through the calculation model can master the evolution of the temperature of lasre remelting process and can provide the theory basis for process parameter selection and optimization.

The effect of particle size of iron and size of reinforce particle on properties of materials was studied systematically by the specimen current direct heating dynamic hot press sintering. It is found that mechanical properties of composites increase with the increasing particle size of iron. The properties of SiCp/Fe composites firstly increase and decrease with particle size of SiC and properties are better when size is 15μm.

Short carbon fiber is used to reinforce phenol formaldehyde (PF) resin/graphite composite. With carbon fiber by thick nitric acid liquid-phase oxidative surface treatment (TNALPOST) and its content 3.wt%~ 4.wt%, the composite flexural strength is increased highly and electrical conductivity is also increased on some degree. To PF resin/graphite matrix material without carbon fiber added, if PF resin content is 15.wt%, its flexural strength is 49.0MPa and electrical conductivity is 111S/cm. But with adding carbon fiber by TNALPOST and the same PF resin content , the composite flexural strength and electrical conductivity approach 68MPa、122S/cm respectively, both mechanical property and electrical property satisfy the requirement of USA Department of Energy on carbon filler/polymer composite bipolar plate. The PF resin/graphite composite without carbon fiber added presents brittle fracture mode, but with carbon fiber added, it presents ductile fracture mode. According to the fracture morphology by scanning electron microscopy, carbon fiber and matrix is on relatively weak boundary bonding state accompanied by fiber de-bounding、sliding、pulling-out and bridge-making to crack, they are main factors contributed to improving composite toughness.

Firstly this paper introduces the flexibility theory of virtual prototyping. Secondly a virtual prototype of rigid-flexible coupling model for beam-carried cranes is built, based on collaborative simulation platform by using the software of UG, ADAMS and ANSYS. Finally the response curves of the displacement for the girder’s centroid with step load and different frequency sine load were analyzed by virtual prototyping simulation. And the corresponding second-order system transfer function is given through the system identification. The result of simulation provided some theory basis for the structure design and optimization of beam-carried cranes.

The design of PVDF transducer is finished and its designing idea and structure frame are presented. The laser ultrasound in nano A1P/SiO2 is detected by the PVDF transducer and the acoustic signal curve is obtained. The ultrasound waveform thermal elastically generated by a rectangular laser pulse is theoretically presented. The ultrasound pulse waveform obtained in the experiment is in accordance with the one in theory. It is shown that this design method is simple, practical and easy to implement.

Aiming at the helical planetary gear reducer with the small module (m≤0.8mm) and big helical angle (β≥20°) applied widely, a novel method of the design and manufacture is come up. The developed reducer matched with the suitable motor not only reduces output speed and inertia of the motor, but also increases greatly stability of tooth meshing. Thus, it could reduce transmission noise and favorably increase the output torque of the motor. So it has a wide application prospect.

In recent years, cluster technology is used more wildly. In this paper, we present a new method to implement a streaming media cluster server. The server is constructed on a high performance cluster which consists of one control node, one storage node and 8 computing nodes. We wrote a parallel program with MPI which run on the cluster. The organization of MPI program is a master-slave scheme. The master interacted with users and scheduled task within slaves. Slaves called streaming media server which sent data directly to user. This can improve the system performance significantly. We can also guarantee the transparence of the service by single access point named IP Tunneling. The system was implemented under Linux platform and tested through simulation testing method. From the testing results, it can be confirmed that the whole system is well designed which achieves high performance, good robustness and high scalability.

In order to resolve the modeling method of logistics network, a basic model named NGM is presented. According to some special characteristics of the real logistics network such as growth, preferential attachment, edge-weighted, and clustering, the basic model is improved and optimized. The modeling method of logistics is analyzed and simulated too. The results of the simulation show that the modeling method is more effective than the traditional logistics modeling theories.

This paper studied a novel 3-DOF hybrid robot, and invented a new hybrid structure which was composed of 2-DOF parallel structure and 1-DOF serial structure. The structure of this mechanism was simple, stiffness and positioning accuracy was high. The control system based on ARM micro-controller was a step motor open-loop control system, which features compact and low cost while the control accuracy can be guaranteed. In this paper, the body composition of the robot was described, and its inverse kinematics were derived and further simplified. Hardware and software of the motion control system was designed in detail and experimented through prototype.

Domestic and foreign scholars have been studied rock characteristics , but the study results not nearly same with rock nonlinear characteristics. it different rock crushing test conducted many studies ,because it has not the rock broken theoretical basis .This paper try to study the deep rock distribution (under the load before static load) by concentrated load ,it is proposed for deep rock fragmentation theory and methods. In the rock is often under stress , the stress number is measure pressure ,the rock stress state is Related for the elastic potential energy stored and the energy is proportional to the rock depth and volume occurrence. when the stress turned from ,the rock energy will accumulate or release .when the rock energy release ,the rock particles displacement may be elastic displacement or plastic displacement.