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In order to study effect liquid characteristic on nozzle atomization process, this article applied Particle Droplets Image Analysis, high speed camera, and Malvern particle sizer to carry out experiment which focused on how Don-q, Score and the concentration of Breakthru S240 affected spraying sheet and droplet spectrum with conventional fan nozzle ST110-03 and anti-drift nozzle IDK120-03. The concentration of Don-q, Score solution was 0.275 % and 0.1 % respectively and the concentration of Breakthru S240 added into Don-q and Score was 0, 0.01%, 0.03%, 0.05%, 0.07%, 0.1%. Whole images and Detail image of ST110-03 and IDK120-03 nozzles' spraying sheet were taken at 0.3 MPa to observe its structure and to analyze the influence of type of formulation and adjuvant concentration using high speed camera and PDIA respectively. And VMD was obtained from Malvern particle sizer. The results showed that: when spraying 0.275% Don-q solution without adjuvant, spraying sheets and VMD of ST110-03 had no significant change compared with water; For IDK120-03, the spraying sheet had slight increase and the VMD almost did not change. When spraying 0.1% Score solution without adjuvant, the spraying sheet decreased by 35.2%, 40.5% individually and the VMD increased by 13.5%, 28.9% separately for ST110-03, IDK120-03 nozzle. Meanwhile, the structure of atomization was significantly affected by formulation. For ST110-03 nozzle, the film region was significantly reduced; fragmentation in film region become seriously with increasing holes in spraying film, and the wave formation was disappeared with thinner rim. For IDK120-03 nozzle, the film region was also significantly reduced; fragmentation in film region also become seriously with increasing holes in spraying film, but the hole was smaller than that of water and 0.275% Don-q. Combined with the analysis of surface tension and viscosity, it was found that the surface tension was an important factor affecting length of spraying sheet, structure of film, the droplet size; with the reduce of surface tension, the length decreased and the VMD increased. For the increase of Breakthru S240 concentration, the length of spraying sheet firstly decreased and then increased. It had the minimum when the concentration of adjuvant was 0.01% and the spraying liquid was 0.1% Score; it had another minimum when the concentration of adjuvant was 0.03% for 0.275% Don-q. Meanwhile, the structure of atomization was affected by adjuvant concentration at different levels. For ST110-03, the perforation disintegration was gradually serious, the hole become bigger when spraying score with adjuvant, and there was still no wave formation even if the concentration of adjuvant was 0.1%; the fragmentation in film region become seriously with increasing holes in spraying film, wave formation gradually decreased when spraying don-q with adjuvant. For IDK120-03, the perforation disintegration was gradually serious, the hole become bigger when spraying score with adjuvant; the fragmentation in film region become seriously with increasing holes in spraying film when spraying don-q with adjuvant. Whereas the VMD firstly increased and then decreased, and the VMD had the maximum when adjuvant concentration is 0.03%. Therefore, it was concluded that the trend of droplet change and the difference of spraying sheet length had certain correlation, and the apparent rule was with the increase of spraying sheet, the VMD decreased; with the decrease of spraying sheet, the VMD increased. Coupled with the analysis of surface tension and viscosity, surface tension was gradually decreased, but the spraying fan did not decreased or increased gradually. Maybe other characteristic of liquid combined with surface tension together depended on spraying fan length and change of atomization region in complicated mixture. So it was deduced that surface tension was one of important factors effecting atomization. [ABSTRACT FROM AUTHOR]

A consolidation theoretical solution of rigid-pile composite foundation, which takes the modulus of cushion, pile and soil in consideration, was derived on the basis of saturated sand drain well consolidation theory. The FEA model of a single pile composite foundation was established in ABAQUS adopting the Modified Cam-clay constitutive model and pore element to simulate the soil between piles. The calculation fit well with the experimental results, which proved the validity of numerical simulation. The influences of thickness and modulus of cushion, the length of pile on the mechanical and consolidation settlement of rigid-pile composite foundation were further analyzed. The results show that : the consolidation rate of rigid-pile composite foundation is quite faster than natural foundation ; the consolidation rate is faster with larger cushion modulus and minor drain diameter ratio ; the consolidation is almost finished during the construction process ; the increase of cushion modulus leads to decrease of consolidation settlement, but the increase of thickness of cushion and drainage soil layer leads to the opposite effect. [ABSTRACT FROM AUTHOR]

Viscoelastic suspension is a newly applicable suspension for a large power and heavy crawler vehicle. The viscoelastic suspension can support a heavy load efficiently when walking and working on the off road, raise the adhesion property of a vehicle, and decrease the impact vibration level of the vehicle. The suspension consists of a metal part and viscoelastic material which are spaced and arranged to notably control vibration by transforming vibration energy into thermal energy to dissipate it into the air due to the hysteretic characteristic of viscoelastic materials. To predict and accurately study the dynamic behavior of viscoelastic suspension and evaluate its vibration damping capability, fractional calculus was introduced because of the facts that the fractional calculus exhibits global correlation and data-fitting well when describing rheological phenomenon. In this context, a fractional order Kelvin-Voigt model considering the geometric factors i.e. A radius-thickness ratio incorporated into a dynamic model of viscoelastic suspension for crawler vehicle was established. In this model, the viscoelastic part was represented by a parallel-combination of a spring whose stress is in direct proportion to the strain and a spring pot whose stress is in direct proportion to the fractional derivative of the strain differentiating from the conventional damping pot with stress being proportional to the first derivative of the strain. A numerical solution was obtained by adoption of a Grumwald-Letnikov fractional derivative definition and a matrix function theory and its calculating codes were programming in Matlab. A history correlation coefficient was achieved to embody the afore-history influence of the viscoelastic suspension on its dynamic behavior. Parameters of a fractional model was acquired by fitting data using a least-square method based on a viscoelastic material tensile test carried out on a Testometric M350-10kN according to GB/T 528-1998 and GB/T 9865.1. For a pragmatic study case, a heavy crawler tractor installed with 8 viscoelastic suspensions was considered to analyze its vibration control effect by establishing its fractional model. Also the parameter influence on the vibration control effect, including exciting frequency, fractional order, and ratio of radius to thickness, was examined. The results showed that, compared with rigid suspension, the viscoelastic suspension exhibited remarkable vibration control capability, especially at the resonant frequency of about 4.5 Hz by reducing the response magnitude of the vehicle body by 64.10% in max value and 66.40% in RMS, thus satisfying the supporting and stable demands of the crawler tractor walking and working on the off road. Radius-thickness has a negative influence on the response magnitude of viscoelastic suspension, that is to say there is an effective way to reduce the vibration by introducing a geometry-modified viscoelastic suspension with higher thickness and lower action aero. Fractional order, however, exhibits a positive correlation to the behavior of the response magnitude, which inspires another valid method of altering the viscoelastic material parameter to perfect the vibration of the crawler tractor. The history-dependent factor gives evidence of the long range correlation of the fractional model, i.e., the system response at current time relates to the whole history whose influence increases with time closer to the current time. This research provides an essential theoretical basis for multi-objective optimization and dynamic design of a viscoelastic suspension for a higher power and heavy load crawler vehicle. Experiment study is an essential procedure as a further study. So our future work will stress the indoor test of a dynamic mechanical analysis (DMA) of viscoelasitc materials, deriving a fractional constitutive model considering the temperature-frequency effect of viscoelastic material, and carrying out an in-situ test of a real crawler vehicle establishing a different-parameter viscoelastic suspension to investigate stable/dynamic stiffness, fatigue features, and vibration control capability under working conditions of cutting, pulling, digging, and crossing over an obstacle. [ABSTRACT FROM AUTHOR]