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Dents in an oil and gas pipeline can be detected by In-line-Inspection (ILI), and structure integrity analysis of the pipe with theses reported dents is important for the safe operation. Strain analysis of the dented pipe is a way of fine assessment and ASME B31.8 has established the strain assessment code and its acceptable range. However, the method of strain assessment is rarely used due to the difficulty of strain calculation for a buried pipe. In this study, features of ILI data are investigated to elaborate the necessary of filtering analysis for strain analysis of the dent with ILI data. Then typical filtering methods are used to smooth the ILI data, and strain analysis are carried out with the smoothed data to study the practicability of strain assessment. Profile and strain of a dent in D813 pipe were obtained by Finite Element Method (FEM). Then different filtering methods were used to smooth the simulated ILI data of the dent which were selected from FEM profile. Strain of the dent were also calculated by smoothed data with the latest ASME B31.8 code, and compared with it from FEM at last to prove the feasibility and validity of the filtering methods with ASME B31.8 code.

Recently incidents related to cracking of girth welds in oil and gas pipelines occurred frequently. With highly concentrated stresses, girth weld defects may significantly reduce bearing capacity of pipelines. Many girth weld defects were detected in the in-line inspection and excavated verification. How to assess the severity of these defects to avoid the excessive and unnecessary repair was a technical challenge. Four different kinds of girth weld defects were manufactured in the 32-inch pipeline and full-scale hydrostatic burst testing were carried out to assess the pressure performance of these defects. Many fitness-for-purpose assessment methods were applied to verify the accuracy of experimental results. After the testing, pipelines with failure defects were cut out to carry out the microanalysis. The research results make us understanding the severity of these defects and avoid the excessive and unnecessary repair of these defects to ensure the pipeline safety.

White light interference technique for topography measurement effectively avoids phase ambiguity in phase-shifting interferometry. The spatial frequency domain algorithm based on scanning white light interference technique has the advantage of insensitivity to noise and higher calculation accuracy compared with other methods. The white light interference sensor is constructed based on nano positioning and nano measuring machine (NMM), the calibrated step height standard of 100±3nm is measured. The spatial frequency domain algorithm is adopted for data processing, the repetitive test result of 97.9nm and standard deviation of 0.48nm are achieved. To verify the measuring ability of complex device, the number ‘242’ on ink box is measured and three-dimensional reconstruction is conducted. The high precision and traceable measurements of micro/nano scale step height standard and complex devices are realized by the white light interference system based on NMM with steady frequency laser interferometer built-in.

In this paper a two-dimension BIST compression scheme is presented; the proposed scheme is utilized in order to drive down the number of deterministic vectors to achieve complete fault coverage in BIST applications. By introducing shifting compression and input reduction, vertical and horizontal compression are realized respectively to achieve two-dimension BIST compression. Experimental results show that the BIST shifting compression based on input reduction can achieve great compression rate as much as 99%. Comparisons with previously competitive presented schemes indicate that the proposed scheme provide an efficient BIST compression approach with lower storage overhead.

Hydrological phenomena in nature are always complex processes. Among the studies of hydrology, prediction of runoff from rainfall is a major issue. This is caused by highly nonlinear relationship, variability of spatial and temporal factors (DIMITRI & KHADA, 2003). Additionally, the data for rainfall in long periods tend to be more available than the record of flow (Sajikumar & Thandaveswara, 1999). Therefore, in order to get precise estimates of runoff, rainfall-runoff models are required. This paper describes three types of rainfall-runoff model and the main calibration methods .

This paper presents an improved approach to Triple Modular Redundancy (TMR) which concerns don’ t care bits of LUT configuration bits and hence classifies the set of LUTs into SEU-sensitive and SEU-insensitive. Unlike the full TMR approach, the improved approach only triplicates SEU-sensitive LUTs and can greatly reduces the area overhead while maintaining the circuit reliability. The proposed approach is thoroughly tested on the MCNC’91 benchmarks. Compare with the full TMR method the proposed scheme can reduce the area overhead by 26.6% on average, at the same time the circuit reliability only reduced by 9.1 %. The improved approach can also increase mean time between failures (MTBF) by an average of six times more than the original circuit.

To make diesel engine Exhaust meet Euro V standard , the most efficient way was to use SCR(Selective Catalytic Reduction).In this paper ,the composition of the urea-SCR system, essential parts and technology of urea-SCR and the strategy to reduce NOx exhaust was analyzed carefully. And through the test analysis, Selective catalytic reduction technical could Euro V diesel engine emission standard had confirmed.

One of the most important parts in the energy feedback electronic loads is the grid-connected inverter, and its function is to feed the detected electrical energy back to the grid for saving energy. In this paper, the principe of the grid-connected inverter is elaborated, then the PI control and the LCL filter are selected, the mathematical model was set up and the feed forward control voltage was added that suppressing the influence on the system produced by the grid disturbance. The simulation was conducted with the help of Matlab/Simulink, from the simulation waveforms it can be seen that the system dynamic and static performance was good, meanwhile electrical energy can be fed to the grid in the way of unit power factor, eventually the feasibility and superiority of the designing scheme is confirmed.

The present paper focused on both turbulent flow and laminar flow at low Reynolds number in a curved duct. The finite volume method on unstructured grid and SIMPLEC algorithm were adopted here and the computation program was design with these methods. Good agreement was achieved between the numerical result and experimental data in the literature, and it shows that the method is reasonable and the program works well. The numerical method was also used to flow simulation with different attack angle and side angle, and numerical results were consistent with conclusion in the literature. Finally, the numerical method used for cases with different Reynolds number at the inlet. Secondary flow phenomena have been researched in the curved duct and some conclusions were derived.

For complex spacecraft assembly conditions, how to play effective and flexible robotic characteristics, and improve production efficiency, is the problem needed to solve.this paper presents a flexible force control method on robotic assembly: a 6-axis force/torque sensor is mounted between tools and the end of robots, the operator operates the load by hands directly, and the system can obtain the force/torque information caused by operator’s hands through gravity compensation algorithm, then the force/torque information is used as input parameters to control the robots moving with the hands. The detailed scheme and algorithms are presented in this paper.

With the rapid development of information technology and computer technology, multimedia demonstration and its related application technology is matured. Multimedia demonstration is the carrier to pass the teaching information. Multimedia demonstration, as one of the multimedia material, is an important content in the multimedia teaching research. In this paper, mainly research the applications status of multimedia demonstration in aerobics skill learning, the production status of multimedia demonstration and multimedia demonstration teaching method in aerobics teaching and action skill learning.

Lytic enzyme produced by Bacillus circulans A1.383-2 was proved to be able to hydrolyze the cell wall of Phaffia rhodozyma effectively and make astaxanthin be extractable by the uniform design. When the hydrolysis temperature and pH to modify the yeast-walls were 37°C and 5.0, respectively, and 33ml lytic enzyme (1603.8u.g-1 dry yeast) was added, over 98% of the astaxanthin could be extracted within 16.5h.

This paper presents a general model to predict resonance frequencies for long-neck cylindrical acoustic resonators. The predicted resonance frequencies by the proposed model are compared with those measured and calculated by Panton and Millers model. It is found that the model developed in this paper can give more accurate resonance frequencies for both the first and higher modes, while the Panton and Millers model can only accurately predict the first-order frequency, and up to 4% error is observed in the predicted higher-order resonance frequencies, mainly induced by the lumped-mass simplification.

This paper designed a kind of efficient IOT transmission platform based on wireless sensor network and GPRS network. Using the multi-mode sensor nodes composed of temperature-humidity senor and acceleration sensor, realize the effective detection of geological disaster, such as landslide and debris flow. After experimental verification, the IOT platform based on the two levels of network structures, can effectively transmit the monitoring point's information, such as the surface humidity, tilt angle and displacement. The system has long transmission distance and low power consumption.The system will have certain engineering value in the field of geological monitoring.

Experimental study of the ozone through catalytic oxidation treatment sludge and rubbish leachate, The impact of different catalysts dosage on absorption rate of O3CODNH4+-NTPpH and other indicators.The results showed that, Dosing Cu-Ni catalyst can increase the absorption rate of ozone, And rubbish leachate ozone absorption rate is higher than the absorption rate of the sludge supernatant; Ozone oxidation catalyst can improve sludge supernatant and leachate the COD removal rate, the optimum mass ratio of 3; Ozone oxidation of sludge supernatant and rubbish leachate is difficult to NH4+-N and organic nitrogen due to preferential oxidation of ozone to convert it to NH4+-N, NH4+-N within the system led to rise, not fall, overall dosing ozone catalyst for the oxidation of NH4+-N had little effect; Dosing catalyst can effectively improve the sludge supernatant and rubbish leachate TP removal, rubbish leachate optimal mass ratio of 3, the optimum sludge supernatant mass ratio of 7; Rubbish leachate pH, with a small amount of catalyst dosage was decreased, while the pH of the sludge supernatant, then with a small amount of catalyst was increased upward trend.

Experiment was based on plus a plant regulator of aerobic composting food waste and sludge mixed, results showed : Ventilation and air supply in different ways, the pile temperature and soluble COD increased with prolonged compost increased first and then decreased trends, pile moisture content, volatile organic matter and water-soluble nitrogen are presented with the composting time has decreased, while the pH value of the hybrid reactor with composting time was down then up trends; Having aeration rate 0.2m3 / h, 0.6m3 / h, 1.0m3 / h of continuous supply trials comparing gas volume of 0.6m3 / h when the best compost and gas volume in the same conditions, the continuous supply way than intermittent air supply composting effect.

The numerical model of the unsteady flow field of ducted propellers is based on CFD (computational fluid dynamics). By applying the numerical model, the unsteady flow field of the ducted propeller with the fracture in different positions of a certain blade is simulated and its unsteady hydrodynamic performance is numerically analyzed. By extracting the fluctuating pressure data of the duct inner wall monitoring points,the fluctuating pressure-time oscillogram of ducted propellers is obtained, and then the spectrum is obtained by FFT transformation of the oscillogram. A blade fracture fault diagnosis technology of ducted propellers, which combines oscillogram analysis method with spectrum analysis method, is put forward by analyzing and studying the oscillogram and the spectrum.

Firstly, the calculated model was created in UG and GAMBIT, and then the Moving Mesh method was adopted to simulate thrust and torque of ducted propeller using FLUENT in the open water. The thrust, torque and bearing force of ducted propeller in three different wake fields were calculated. And the influence on the performance of ducted propeller by the wake fields was analyzed.

Modern structures tend to be more and more complicated, setting up the complete calculation model and getting each part of the dynamic response is almost impossible and unnecessary. The substructure analysis technology is effective for the dynamic analysis of large and complex structure. The substructure theory has become increasingly mature and perfect, and has been widely used in structural analysis and calculation. This article simply introduces the principle of substructure pseudo dynamic test, and using the finite element software—ADINA simulates a steel frame.

Use Adina finite element software, established the finite element model of the the volume 10000m3LNG storage tank, against the concrete outer tank of full containment type LNG storage tank vertical seismic action seismic response analysis. Take acceleration seismic input method, select the four categories venue seismic waves, LNG storage tank stress analysis of vertical seismic action, come in different earthquake LNG storage tank outer tank equivalent stress, hoop stress and axial stress distribution.

Departure from the stress state of the steel pipe concrete dye column node, axial force, steel pipe column end moments and stained end vertical shear strength Shear strength concrete filled steel tube the formula, using the finite element analysis software ANSYS to establish a three-dimensional nonlinear finite element model, comparing the results calculated by the finite element calculations and formulas seen, the model is applied to the concrete filled steel tube - steel beam finite element nodes analysis.

This paper makes research on the stiffness of CFT column and steel beam joint with inner stiffening ring by using finite element analysis (FEA) program ANSYS. Analysis result indicates that the most important factor influencing the stiffness of the joint is the height of cross-section of beam while the thickness of the web plate hardly has any influence on the stiffness. The M-θ model of the CFT joint given by this paper can be used in practical design.

The broken-blade propeller induced centrifugal force and hydrodynamic lateral component force will cause the whirling vibration of the shaft system while one of the propeller blades breaks at different positions. Such whirling vibration is investigated in this paper, and the time domain waveform is obtained through using the finite element method. The frequency domain vibration is then calculated by applying Fourier transformation on its time domain waveform. According to the respond results of both time domain and frequency domain, the fault diagnoses technology of shaft vibration is proposed.

Based on the classification system of modern Chinese words classification system and characteristics of military documents field, the military document words are classified and descripted with morphology, syntax, complex feature, semantic and reference. And a military documents electronic lexicon prototype is designed. This lexicon can meet the requirement of military document intelligent processing well proved by application of military documents electronic lexicon.

In order to provide a theoretical basis for the use of lacustrine soft clay hard shell layer, the first thing to do is understanding its bearing capacity characteristics. Based on the project of Nan-Mao section in Hunan provincial highway S204, combining with bearing capacity test, the bearing capacity characteristics and failure mode of hard shell foundation was comprehensively analyzed. From the field bearing capacity test, it is found that the PS curve of hard shell layer has obvious changes from elastic to plastic, while the PS curve of soft soil layer under hard shell layer just has elastoplastic stage from the beginning, and the failure mode of foundation mainly are punching failure and general shear failure. So for the quality control of lacustrine hard shell soft foundation mainly includes two aspects: the deformation and overall stability.

For the manufacturing of high strength automobile body safety parts, a digitally controlled pilot production system for the hot stamping process was developed, including an electro-servo press, a numerically controlled heating furnace, a blank conveying system and a synchronized production line control system. By using the in-house developed hot stamping production system, automobile B pillars were manufactured from a proprietary high strength steel developed by Wuhan Iron and Steel (Group) Corporation. The steel blank was austenized in the furnace at 950°C for 5 min, followed by hot stamping. The overall cooling rate of the heated blank was above 35°C s-1 during the hot stamping process, which ensured a uniform martensitic microstructure with an average hardness above 460 HV1, a room temperature of tensile strength of 1489MPa and an elongation of 6.87%. The deviation of the formed part from the 3-D model is in the range between +0.623mm ~ -0.826mm.

In order to transform dynamic complex modulus into static relaxation modulus, an advanced Shear Rheometer is used to get complex modulus master curve of asphalt mixture. Dynamic modulus master curve is transformed into static modulus master curve basing on the relaxation time spectrum. Results show it is feasible that the dynamic modulus master curve can be transformed into relaxation modulus master curve in wide frequency domain basing on the relaxation time spectrum.

The experiment on joints of concrete filled thin-walled steel tube and the composite beam is carried out in 8 specimens, and mechanics performance of all type joints is concluded in general. The test results indicate that each joint has higher bearing capacity and better ductility performance. Solid65 and Shell181 Elements of ANSYS finite element program are adopted to simulate concrete and thin-walled steel sheet of composite beams and columns. Calculation results in theories proved conformity with the test in primary.

Quantum-behaved particle swarm optimization algorithm (QPSO) was proposed as a kind of swarm intelligence, which outperformed standard particle swarm optimization algorithm (PSO) in search ability. This paper presents an improved QPSO with nonlinear controlled parameter according to the fitness value of the particles. Simultaneously, we apply the improved QPSO to solve the problems of target position measurement. The experimental results show that the improved QPSO has faster convergence speed, higher measurement accuracy, and good localization performance.

As a newly emerging frontier interdiscipline, smart materials and structures possesses the great development potential and wide application prospect, and has become one of the research focuses at home and abroad.The research status of smart materials and structures is summarized, and its key technologies are analyzed. the future development of smart materials and structures is presented.

The numerical model of the unsteady flow field of ducted propellers is based on CFD (computational fluid dynamics). By applying the numerical model, the unsteady hydrodynamic performance of the ducted propeller with the fracture at different positions of a certain blade is numerically analyzed under three different wake current fields. Based on regress analysis ,the relationships between the mean KQ、mean KT and the quantity of the blade fracture of ducted propellers are obtained; and the relationships between hydrodynamic coefficients Kp, KQ, KFy (Bearing force coefficient of the propeller) and wake current fields , the quantity of the blade fracture are respectively further analyzed. The results show that: (1) with the increase of the quantity of the blade fracture, the amplitude of bearing force periodic variation of propellers increases, while the thrust and torque reduce; (2) the bearing force of propellers is similarly sine-varying, and the frequency of its variation is unrelated to the normal variation frequency of the wake current field. The more non-uniform the wake current field is, the more the amplitude of its periodic variation is; (3) the thrust and torque of propeller are similarly sine-varying, and the frequencies of their variation are related to the normal variation frequency of the wake current field. And the frequencies equal the shaft frequency multiplied the normal variation frequency of the wake current field. The more non-uniform the wake current field is, the more the amplitude of their periodic variation is.

This paper introduces the omnidirectional vibration sensor based on MEMS three accelerometer, which is used to solve the problem that the tradition vibration sensor cannot acquire multidimensional vibration signal effectively, on the background of underground distributed passive localization.It has MEMS accelerometer as the core detection unit, including three dimensional vibration detection unit, signal conditioning unit and power supply unit. It adopts the spherical shape ,which consists of Aluminum shell、Potting material of Epoxy resin and Multilayer circuit board. By means of finite element analysis and Field test, it shows that this sensor can effectively get omnidirectional vibration signal vector information, and the engineering application value is great.

According to bonding strength weakening in SRM bonding structure, the decreases of elastic modulus in adhesive layer have been used to characterise the bonding strength weakening in adhesive layer. Ultrasonic propagation characteristics with bonding strength weakening in adhesive layer has been simulated. Based on analysing the relation between reflection coefficient and incident angle, the optimal test strategy has been put forward. According to test strategy, the experiment of ultrasonic oblique incidence has been done to test bonding strength weakening, the average energy of reflected wave from test points has been taken as signal property to characterise reflection coefficient. The results show that the energy of reflected wave can reflect the extent of bonding strength weakening, can effectively achieve quantitative test of strength weakening.

In order to optimize the hot deformation processing, useful and efficient mathematical models able to evaluate the different aspects of the response of plain carbon steel to hot plastic deformation are among the most important prerequisites. In this paper, a group of mathematical equations were developed according to a series of experiments data to model the austenite grain evolution, static and dynamic recrystallization during-deformation and post-deformation of plain carbon steel. And then those equations were implemented into ABAQUS6.5 (License Agreement Identifier: 27SHANU) using the VUMAT for numerical simulations of cylinder specimen compression.

In hot metal forming processes, the material is subjected to the thermo-mechanical processing. A fully three dimensional thermo-mechanically coupled FEM-simulation of an eleven pass hot rough rolling process of H-beam has been performed. Microstructure evolution equations available in literatures were incorporated into the commercial FE solver ABAQUS/Explicit, through user defined subroutine VUMAT, to simulate the microstructure evolution. Since it’s impractical to obtain the austenite grain size distribution in the beam blank during industrial hot rolling, the calculated rolling loads are compared with the mills loads instead of grain size comparison between the predicted average value and the real ones.

This paper presents a passive method to control low-frequency noise in a cylindrical structure by using multi-modal T-shaped acoustic resonators. The feasibility of noise transmission control on the cylindrical structure is investigated, including a detailed experimental evaluation of the control performance using a single resonator and a resonator array consisted of different resonators. Finally, six long T-shaped acoustic resonators are used to target the first four lowest cylindrical cavity resonances, and up to 9 dB noise reduction is achieved, and broadband improvement of noise reduction is also observed.

Hot rolling is a basic metal forming technique that is used to transform preformed shape into final products of forms more suitable for further processing. As the hot stock progresses through the forming surfaces, the shape eventually reaches a constant state. With the assumption of forming process has reached steady-state condition, a simulation technique based on elements re-meshes has been constructed to analyze the H-beam metal hot roll process. The technique includes the following approaches: the solution was halted as soon as the steady-state criteria were met, and the plane of elements, which first satisfied the steady-state criteria were written to database, SSES for short; a two-dimensional model was created to model the hot stock cooling between the two roll passes and a geometric part was generated and meshed with quadrilateral elements to transfer the nodes temperatures; a new three-dimensional model extruded from the two-dimensional model was constructed to model the next roll pass with the transfer of nodes temperatures and element integration points equivalent plastic strain(PEEQ), identifying the plastic deformation extent for the classical metal plasticity models, from the new two-dimensional model and the first three-dimensional model respectively. Gleeble-1500 tester is used to get the true stress and true plastic strain data for modeling the yield behavior of material Q235. The effectiveness of the simulation technique has been proved by a simulation of 11-pass H-beam rolling process.

The method of trigonometric series is one of widely used methods for calculating artificial ground motion. But using this method the speed of time, it was found that the zero line must exist the phenomenon of drift. This text fore person the foundation of the research up, a kind of more perfect model of differentiable nonsingular strength envelope function is proposed .a better resolve this problem. Passing the calculation proved that the new method is reasonable and effective.

In order to improve the reliability of a planet carrier, a simulation method based on multi-objective design optimization was developed in this paper. The objective of the method was to reduce the stress concentration, the deformation, and the quality of the planet carrier by optimizing the structure dimension. A parametric finite element model, which enables a good understanding of how the parameters affect the reliability of planet carrier, was established and simulated by ANSYS-WORKBENCH. The efficiency of the design optimization was improved by using a polynomials response surface to approximate the results of finite element analysis and a screening algorithm to determine the direction of optimization. Furthermore, the multi-objective optimization was capable of finding the global minimum results in the use of the minimum principle on the response surface. Computer simulation was carried out to verify the validity of the presented optimization method, by which the quality and the stability of the planet carrier were significantly reduced and improved, respectively. The methodology described in this paper can be effectively used to improve the reliability of planet carrier.

Effects of coagulation and algae removal was investigated, based on the micro-polluted raw water in the southern China, which was characterized with low-turbidity and high algae-laden. The different removal efficiency by the Ozone, permanganate and Ozone/hydrogen (O3/H2O2) processes was summarized at the pilot study level. The results showed that the pre-oxidation process could enhance the treatment effect. However, compared with the other two processes, the process of O3 was less effective than either permanganate or O3/H2O2 process.

In order to study viscoelastic properties of asphalt mixture, an advanced Shear Rheometer is used. The continuous dynamic frequency scanning test is carried out, which can get full-temperature-full-frequency master curve of asphalt mixture by the time-temperature equivalence principle. The CAM model acts as the rheological model for studying viscoelastic properties of asphalt mixture, because CAM model’s parameters have clear physical meaning. Then viscoelastic properties of asphalt mixture are studied basing on the four equations of CAM model in the full-temperature-full-frequency range.

This paper select the appropriate calculation and analysis models and examples, using finite element analysis software ANSYS to compare and analyze the dynamic properties of three large space shear walls of different thickness. The result indicated: the effects of the large space shear wall structure to torsion with the increase of wall thickness.

Taking a structure of single-degree freedom as analyzed object, the problem of structural dynamic response to blasting vibration loads was transformed into the problem of that to a series of simple harmonic loads with wavelet packet method. A safety criterion of structural response to blasting vibration has been put forward, which is more detailed, reasonable and scientific than others in use with involving parameters related to structural characteristics, blasting energy, blasting amplitude, blasting frequency and blasting duration.

To the exacting underwater engineering and waterproof projects, the impervious performance of concrete plays a crucial role in the whole project. XYPEX is a special crystalline powder waterproof material, it is new and effective which is widely used in the basements, dams and other waterproof projects. Adding steel fiber into concrete, the strength of concrete will obviously be improved. The paper makes a comparison of the compressive strength, splitting strength and impermeability test of concrete specimens with two different materials-XYPEX (waterproof material) and steel fiber, and also studies the effect of the two different materials on concrete compressive strength, splitting strength, impermeability and relevant laws, along with discussing the reaction mechanism because of the addition of this two materials.