Advanced Materials Research Vols. 1061-1062

Abstract: It’s important to study the vibration characteristic of submarine pipelines under current for reducing the harmful vibration. Research on fluid-structure interaction of submarine pipeline under current was presented. The pressure and velocity distribution of flow field around pipe with different velocity of flow were studied by ANSYS finite element software. The results show that the pipe is under the action of drag force along the direction of flow. The drag force increases with the flow velocity.

Abstract: A new type of vibration platform was presented and its dynamic characteristics was studied in this paper, A virtual prototype model of vibration platform was built by using software Soldworks and ADAMS.The flexible body model of spring was built based on ADAMS flexible module,rigid-flexible coupled dynamic of vibration platform were analyzed by using simulation, the natural frequency, model of vibration and frequency response were further analyzed. The stiffness of spring and flexible cable were optimized according to the analysis results, The post-optimality simulation results show that the stability and frequency response of vibration platform have improved.

Abstract: When finite element method was adopted in acoustic analysis, area source was defaulted to be of the same amplitude and phase in its whole region. While in practical, there are differences in amplitude and phase between different parts of the area. In this paper, the area source was divided into several sub-area sources so that the source can be modeled with higher accuracy. The optimized area sources were used in simulation of interior sound field of high-speed train. Calculations prove that the simulated result has very good agreement with the measured one.

Abstract: Acoustic transform algorithm plays an important role in sound pressure reconstruction. According to a new sound pressure reconstruction of near-field acoustic holography based on Fourier transform-source simulation technique, this article through a simulation experiment with the models of Simply Supported Plate Sound Source, verify the feasibility of the method. Furthermore, in order to verify the effectiveness of this method, this paper analyzes the impact factors that affect the accuracy of the Reconstruction. And it does simulation analysis mainly from the parameters of the Virtual Source Plane, the Distance of the Holographic Measurement and the parameters of the Holographic plane. Therefore this study provided referencing basis for later study on complex field of sound pressure reconstruction based on this technology.

Abstract: In order to improve metering accuracy of air suction type no tillage seeder in maize stubble ground operation, the vibration parameters of air suction seed metering device of the machine are tested and analyzed. Using the method of orthogonal experiment, with forward speed, ditching depth, ridge direction as the influence factors by experimental study on vibration characteristics.The results showed that in no tillage corn field conditions,Stubble height 10-30cm, ridge height is 0-8cm, the soil moisture content 19.78%, The soil temperature 12.7oC. Effects of sowing machine vibration frequency spectrum of 3.46-12.30Hz and 33.50-50.50Hz, the two band spectrum reflects the vibration characteristic of planter operation in the field, can be used as indoor and virtual test selection of reference data. The test results show that: the main factors causing vertical vibration of no tillage seeder metering device is 90o ridge direction, i.e. the surface roughness is greater, causing the vibration of no tillage planter seeding device more. The second is a seeding machine forward speed for 7km/h, i.e., no tillage planter work faster, causing vibration the greater. Finally is the sowing depth, the factors and agronomic seeds, soil fertility, soil humidity etc. Agronomic requirements are closely related, for the smaller vibration effect of no tillage seeder metering device.

Abstract: In order to study air-suction when tillage planter in the field farming, Vibration due to the surface roughness of the resulting excitation tillage effects on seed planter of the device, Derivation of the air-suction device tillage planter seeder vibration characteristics of the mathematical model, Vibration characteristics of the mathematical model derived gas suction device tillage seeder seed planter primarily by structural properties, Forward speed when operating, Seed row distance between the soil surface, Soil roughness and soil sticky decision. Can predict and analyze working condition tillage planter seed quality through the establishment of the vibration characteristics of the mathematical model.

Abstract: The wing structures of long-range, high-speed flight vehicles bear vibration during the flying time. The high temperatures caused by aerodynamic heating can greatly change the elasticity properties of the materials in a high-speed flight vehicle, leading to an alteration in the vibration characteristics of high-speed flight vehicle structures. In this paper, the high-temperature environment test system and vibration test system were combined to conduct a thermal-vibration test for the composite trilaminated wing structure that comprised composite materials and metallic materials. The vibration characteristics of the composite trilaminated wing structure, such as natural frequency and vibration mode, were obtained in 200°C, 300 ^oC and 400 ^oC environments. The results provide an important basis for the dynamic characteristics analysis and safety and reliablity design of wing structures comprised composite materials and metallic materials under a thermal-vibration environment.

Abstract: In this paper, based on the finite element method and ANSYS software, the dynamic responses of permeable breakwater under wave load response is analyzed and studied. Taking the method of combining modal analysis and power spectrum analysis research on dynamic response of breakwater in the frequency domain and the principal stress and displacement distribution of the structure in the exceedance probability of 0.7%. The results prove that the finite element method of power spectral density analysis can provide effective guidance for the actual engineering.

Abstract: The sloshing fluid inside the tank car which is moving influences importantly on the working of the tank car. The user-defined function second development of the software FLUENT was adopted. The force variation of the tank on the front wall under different working conditions was calculated and the reasons of this variation and the influence on the tank were both analyzed. Little influence on the tank by the sloshing fluid was obtained without energy source. When the tank slowed down, the force peak value remained within the first period of the fluid sloshing, which provided the selection of the tank at the accelerating moment with the foundation.

Abstract: The thermal deformation of reflecting optical system in the ambient temperature affects the system performance greatly. Based on the results of thermal balance test, the paper has made a full analysis to the deformation of reflecting optical system on the high-low temperature using the finite elemernt method,so as to validate whether the optical system meet the requirement of optical image design and temperature. This method can combine the thermal optical analysis and thermal balance test data effectively ,and therefore the most actual thermal optical anslysis model can be obtained to guide the concept and optimization of reflecting optical system.