Search results

Unit tri-axis gear system structure The choice of the optimization objectives of the gear system in co-rotating twin screw extruder mainly is considered to two aspects: one is mechanical properties, that is all components have sufficient bending strength, surface stiffness and life for fulfilling the drive requirements, and the mechanical specifications of various parts in the gear system are well-distributed to ensure the performance; the other is economic indicator, that is minimizing gear volume and weight by reducing the distance between the centres of gear pairs in conditions of performing drive, and easy to be manufactured and utilized.
Optimization objective functions The parameters of the gear determine the mechanical properties and affect the geometric dimensioning.
The formula of contact strength safety coefficient is [10] (6) Where, is the contact fatigue limit of gear; , , , , , , , , , , K are the factors for contact fatigue strength according to the design standard; is the torque on the small gear; is the face width coefficient of the small gear; is the pitch circle diameter of the small gear.
Meanwhile, the formula of gear bend fatigue strength safety coefficients is [10] (8) Where, , , , , , , , , are the factors for bend fatigue strength according to the design standard; is the bending fatigue limit of gear root.
Mechanical property constraints Mechanical property constraints include the constraint of the contact fatigue strength and the constraint of the bending fatigue strength.

Select the characters of landslide, geological structure, elevation, slope, slope, earthquake, rainfall and other factors as analysis variables.
Combine GIS with fuzzy mathematical evaluation method, develop the landslide stability evaluation plug-in and then divide the risk regionalization of study area, in order to avoid occurrence of geological hazards in the area, reduce casualties and property losses.
It refers to the slope in a state of flux for a variety of natural or man-made factors destroyed the original mechanical balance, under the action of gravity or other, along with a weak overall, slow and intermittent forward even suddenly moves down the bad geological phenomenon of [2], in a certain terrain and geological conditions.
Landslide has the environmental conditions, and induced condition, the slope characteristics, formation lithology, geological structure, topography, earthquake and rainfall, and other factors, in-depth study systematically dominant factors and inducing factors and the occurrence and spatial distribution of landslides, the relationship between the work of protecting against and mitigating earthquake disasters have important application value.
In recent years, GIS has been widely applied in the study of slope disaster, slope information management, the main associated with dynamic and static environment factors analysis of landslide, landslide disaster spatial prediction system and slope disaster warning system four aspects [4].

The simulation results indicated that the method proposed in this paper can make the high-power induction motor start fast and smoothly with both high-torque and low starting current, and it has a better starting performance than traditional starting methods and the advantage of not affecting power quality.
As a result, the voltage drops a lot, and the motor starts with great difficulties, which reduces the power quality and affects the normal operation of other electrical equipment in the same grid.
In this method, it tracks and compensates the reactive power of the motor, in order to decrease the reactive power deficiency (or decrease the line’s reactive current), the power and voltage loss, to improve power factor and voltage quality.
(a) (b) (c) (d) (e) Fig.7 Simulation waveforms for 160kW induction motor with DVC full-voltage starting Table 1 Comparisons of starting performance for Different starting methods Starting Properties Starting Methods Direct starting Soft starting DVC full-voltage starting bus voltage (V) 337 205 380 bus voltage (pu) 0.84 0.51 0.95 starting transient current (Amps) 2000 1200 540 starting transient current (pu) 7.4 4.4 1.99 Phase angle(degrees) 77 82 10 Power factor 0.225 0.139 0.985 Reactive power(kVar) 1140 760 50 starting Time(s) 0.6 5.8 0.46 From Table I, due to the large starting current and large voltage drop, it is not suitable for high-power asynchronous motor to direct start.
Low power factor affects the power quality of the local distribution grid.

In order to reduce appropriately the memory space and computing time required and ensure the accuracy of analysis results, some minor details such as chamfers, fillets, bolt holes, etc can be omitted and only consider the most of the major factors of model when the solid model to be simplified.
The material properties of the whole system are shown in table 2.
Material properties of comprehensive fault simulation test-bed Material name Elastic modulus /Mpa Poisson's ratio Density /kgm-3 Corresponding parts aluminum alloy 70000 0.35 2700 Base, bearing, support steel 210000 0.3 7800 Shaft, rolling bearings Fig. 1.
The model is meshed free according to the material properties of each of the parts, and the grid about the axis and rolling bearings in thinning, the finite element model of rotor-rolling bearing-base is shown in figure 4.
Li: Mechanical Engineer .2010, 5:14-15

Many factors influence the effectiveness of traditional binders used for soil stabilization, including anions present in the soil and carbonates.
Introduction Factors affecting the use of traditional binders as stabilizing agents continue to be the subject of many advancements.
Effect of industrial wastes on the physical and engineering properties of soils.
Alcover, Microstructure and geotechnical properties of lime-treated expansive clayey soil.
Fagel, Swelling properties and lime stabilization of N'Gaous expansive marls, NE Algeria.

Permeability distribution interval graph Macro-Control Factors Lithology, physical property, pore type and structure, mineral composition and compaction of reservoir were controlled by environments of sedimentation, sedimentary facies, diagenesis and others macro geology factors.
And the formation and distribution of ultra-permeability reservoirs were also controlled by those factors [2,3].
Different environments of sedimentation are corresponding with different sandstone grain size, this leads to different physical properties[4,5].
In this situation, mechanical compaction is strong.
Characteristics and master control factors of petroliferous properties of low permeability clastic reservoirs of Yanchang formation in the upper Triassic of Jiyuan area in Ordos basin[J].

Research on Fiber Preparation Section with Life Cycle Assessment Theory Jie Song1, a, Na Jia2,b , Bing Ge3,c and Jun Hua4,d 1 College of Mechanical and Electrical Engineering ,Northeast Forestry University Harbin Heilongjiang, 150040 2 College of Mechanical and Electrical Engineering ,Northeast Forestry University Harbin Heilongjiang, 150040 3 College of Mechanical and Electrical Engineering ,Northeast Forestry University Harbin Heilongjiang, 150040 4 College of Mechanical and Electrical Engineering ,Northeast Forestry University Harbin Heilongjiang, 150040 asongj2017@sina.com, b jiana1975@sina.com, cgebing2012@sina.com,dhuajun81@163.com Keywords: Fiber Preparation Section, Life Cycle Assessment, Environment Load Factor, Technology and Equipment Abstract.
Thus, the environment load factor of each process can be determined, as shown in Table 1.
At present, the main characterization models are load model, SETAC equivalent model, inherent chemical properties model, overall exposure - effect model, point-source exposure-effect model, etc.
Through an in-depth analysis to the fiber preparation section, the environmental load factors are determined.
In all, with the theoretical framework system of the fiber preparation section, as well as the end-based evaluation methods, the extent of the environmental impact affected by the different production techniques and devices match is evaluated.

Membrane is the key that restrict Membrane Bioreactor technology be extensive applied, the membrane flux is an important factor to measure membrane, membrane fouling is the main factor which result in the membrane flux low, the membrane fouling research on a new type of hydrophilic PVA membrane .The experiment results show that the membrane flux is high with the use of PVA membrane.
Key factor in the current constraints of the MBR is the high cost of membrane modules, and the membrane material with the real resistance to pollution, aperture small, hydrophilic and easy to clean has not yet widely used [2].
Fig.2 Effect of COD removal Fig 3 Membrane flux’s change while starting circulate Membrane fouling MBR membrane fouling is running a series of factors that collectively increase the membrane resistance.
Conclusion There are many factors that affect the membrane fouling.
Membrane material properties, shape of the membrane, etc., membrane fouling have some role in the implementation of reasonable mitigation measures, the present study, the polyvinyl alcohol (PVA ) membrane can get a good stable membrane flux, the average flux 168 L/m2.h, membrane flux can be recovered after the decay, recovery rate is 94%.

Multiple damage modes can affect a region concurrently and their interactions are accounted for.
These models had uniform material properties and artificial stress concentrator that encourage damage initiation at a pre-defined location was not required.
Fig. 2: Force response of simple tensile test case with varying elemental aspect ratio using the Abaqus default characteristic length calculation An algorithm was proposed to calculate the characteristic length, accounting for the aforementioned factors.
These very soft elements can potentially undergo very large and unrealistic deformations and adversely affecting the stability of the finite element process.
Concluding remarks Three different issues affecting the implementation of a high fidelity material damage model for the simulation of composite structures were discussed.

Effective, controlled micro-alloying is very important in the production of high strength steel bar of consistent microstructure and hence mechanical properties and weldability.
Mechanical Properties of Steel Bars for the Building Industry in Hot-rolled State Grade yield strength /Rm(MPa) tensile strength /ReL(MPa) Elongation (MinValue) /A(%) HRB500 500 455 15 HRB400 400 540 16 HRB335 335 630 17 Composition Design of the High Strength Steel Bars.
The content of carbon, silicon and manganese ensures the mechanical properties of steel and end-point control at BOF process.
The simplicity of the design is a factor in the low capital investment costs.
Table.7 Main Mechanical Properties of HRB500 Steel Bars Nnominal diameter Yield strength /Rm Tensile strength /ReL Elongation /A/% 8 670-580 540-580 21-29 12 660-740 535-580 16-31 40 665-725 530-570 17-26 Summary The strength of the steel bars for the building industry can be increased by micro alloying with vanadium nitride.