Papers by Keyword: Vibration Mode

Abstract: In the process of calculating the crankshaft frequency and vibration mode, free mode is always applied for the crankshaft modal analysis. Considering the effect of centrifugal force generated by the rotation to the crankshaft frequency and vibration mode, the frequency and vibration mode of multi-speed cases are calculated, and compared, which fully shows the vibration situation of the crankshaft in the process of actual working situations, the results match actual situation.

Abstract: This paper mainly adopts the finite element analysis software ANSYS to calculate and analyze the dynamic characteristic of aqueduct structure,using added mass method to deal with interaction between water and aqueduct wall, and get the natural vibration frequency and main vibration mode of U-shaped aqueduct in different water depth. The calculation result shows that water has a small effect on the vibration mode of aqueduct structure, but has a greater influence on the natural vibration frequency of aqueduct structure; natural vibration frequency of aqueduct structure decreases with the depth deepening. The research results provide the basis for the seismic design and protection of Sunjiagou aqueduct.

Abstract: Dynamiccharacteristic analysis of bridge structure is the foundation of the seismicresponse analysis and seismic design, includes the calculation and analysis ofnatural vibration frequency and main vibration mode.The natural vibrationfrequency not only is the index of bridge structure rigidity,but also is the basisof identifying whether the bridge structure resonance occur. In this paper thehealth condition evaluation of highway bridges was carried out based on anambient test and finite element analysis, using finite element analysissoftware ANSYS calculates and analyzes the dynamic characteristic of bridgestructure, then gets the natural vibration frequency and main vibration mode ofbridge structure, finally compares with results of ambient tests. The resultsshowe that, structural dynamic stiffness of Rencungou Viaduct and YingyugouViaduct can meet design requirements; but structural dynamic stiffness ofLiaoyugou Viaduct is lower

Abstract: Considering the effect of centrifugal force generated by the rotation to the crankshaft frequency and vibration mode, the frequency and vibration mode of multi-speed cases are calculated. The results showed that the impact of the centrifugal force on the crankshaft vibration increases with the increase of rotational speed, especially in the high speed region, this phenomenon is more obvious. From low speed to high speed, the vibration frequency has a large deviation, which shows that in this case, it is necessary to consider the frequency change caused by pre-stress.

Abstract: The traditional identification method of surface crack has some shortcomings such as detection equipment complex, high requirements for operator and not suitable for large-scale structure inspection, vibration method is applied to identify surface crack in steel rods in this paper, using the method of calculating modal analysis combined with time-frequency wavelet analysis. The research on damage identification is performed on steel rods with different deep crack. The research results show that the accurate damage location can be judged by wavelet modulus maximum and the quantitative analysis of single crack identification can be achieved by constructing mathematical expressions of a single crack damage degree and damage index Lipschitz index. The research would province some guidance for engineering applications.

Abstract: Transmission tower is a widely used higher order statically indeterminate spatial structure, as the pillar of power transmission, modern society are increasingly concerned about its safety and reliability. This paper establishes a large-scale three-dimensional space model of transmission tower by using the finite element method, calculate and analyse the first six vibration modes and frequencies of this transmission tower, study the characteristics of each order vibration mode. These research results provide some references of design for the large-scale transmission tower.

Abstract: This paper researched dynamic characteristics of 5-DOF scraper chain handling robot by finite element modal analysis. Firstly established the whole three-dimensional model with Solidworks, secondly, transferred it into the ANSYS finite element analysis software to analyze dynamic characteristics in two fixed work positions when it was grasping a scraper chain and carrying a scraper chain on a rail line. It was found the weak component which vibrated heavily was the big arm from the analysis of the top 5 order vibration mode. Then studied modal analysis of the big arm to obtain the its inherent frequency and vibration mode. Finally put forward some suggestions about the design of the handling robot and improved its dynamic characteristics which is meaningful to increase its stability and reliability.

Abstract: A 3-D finite element model for Yueyang Dongting Lake bridge was established with a large scale general finite element analysis software, and the subspace iteration method was adopted to analyze the natural vibration characteristics of the bridge, meanwhile, the influences of settings different types of central buckles at the mid-span of the main spans between the main cables and girder on the dynamic behaviors of the long-span suspension bridge with deck-truss composite stiffening girder were studied. The results show that compared with only setting short hanger cable at mid-span, the the whole rigidity of suspension bridge is raised and the natural frequencies increase by the setting central buckle, but various types of vibration modes are affected in different extents; among all of these vibration modes, the antisymmetric vibration and Longitudinal floating of stiffening girder are most obviously affected. The stiffness of central buckle has a great influence on the vibration of main cable, while compared with only setting short hanger cable, the vibration of main cable increases 7.32% while setting the rigid central buckle. The conclusions of this paper provide theoretical basis for the using of central buckle in long-span suspension bridge.

Abstract: The large span suspension structure is easy to generate larger vibration due to its smaller stiffness. For this problem, a finite element modal analysis method that considers the effect of initial pre-stress is proposed. The finite element model of the structure is established by using Link10 unit of the finite element analysis software ANSYS. Then the first four order natural frequency and vibration mode under different initial pre-stress is solved by the subspace iterative method. And the experimental test system based on MEMS sensor is designed to analyze the layout of test points and exciting vibration mode of the structure. The test system measures the inherent frequency and the first two order vibration mode under the action of different pre-stress. The results show that the numerical analysis results are basically consistent with the experimental results and the inherent frequency of the structure distributes in the plexus intensive form. And the inherent frequency of the structure is related to the pre-stress. The bigger the stiffness of the structure, the greater the inherent frequency is. It proves that the theoretical analysis results are correct and the experiment test system can be used in the structural dynamic test.

Abstract: Micro turn-milling has superiority on the productivity and the quality of work pieces, and is more suitable to machine micro-shaft parts and desirable miniature parts based on the turn-milling technology. On the basis of ADAMS and UG software, kinematics simulation of complete machine has been performed, meanwhile, the natural frequency and vibration mode of micro turn-milling machine tool has been analyzed by adoption of modal analysis in this paper. The results forecasts dynamic characteristics of micro turn-milling machine tool. It also provides important reference frame of dynamic optimization design of micro turn-milling machine tool.