Papers by Keyword: Modal

Abstract: For the fracture failure phenomena occurred in random vibration experiment of the isolation clamp cylinder on the aerospace vehicles, the NX NASTRAN was used to make the finite element modeling for the overall structure of cylinder and analyze the random vibration response. The simulation results show that the maximum RMS stress of the clamp was 96 MPa at the test load conditions. The position of the maximum RMS stress is consistent with the one where fracture happens during vibration test. According to finite element analysis results, the original structure has been modified. The maximum RMS stress of modified structure is only 21.8 MPa.

Abstract: In the study of the dynamic characteristics of the system, should pay attention to the influence on the dynamic performance of the system mode change. Mode change is closely related with mutation phenomena of mode localization process, in the natural frequency with the change of parameters, with a large curvature are quickly turned to separate the two natural frequency curve in the close position. Mode change will lead to the drastic changes in the natural frequency and modal energy, the variation of system parameters is also the location of the influence degree mutation position. Based on the modal characteristics of unique two stage power branch double wide helical planetary composite transmission system, studied the mode change phenomena, reveal the modal system changes.

Abstract: This study is based on the graduation design for undergraduate course. In the paper, finite element analysis software ANSYS had been used to create the finite element model of a cannon barrel. On this basis, the vibration modal analysis of the barrel was conducted. Through the model analysis, the natural frequency and modal shape of the cannon barrel was obtained. The situations of stiffness strength and elasticity deformation about each part of the barrel were got by analysis of the modal shape. By this way, we can verify the rationality of the barrel design .Also it can provide improvements of the weak place of the structure for people to improve the stiffness and shooting precision of the gun, in order to make the dynamics characteristics of the gun more reasonable.

Abstract: In this paper, we depart from the basic vibration equation deduced from Vibro sand tower structure recurrence formula. Using ANSYS finite element software to simulate the red sand of the top ten tower structural vibration modal. Of which the first two modal solutions in accordance with the conventional prismatic cantilever closer to theoretical calculations, the results of the finite element solution proved authentic, we provide a theoretical basis for the use of finite element methods for solving the structural problems of sand washing tower.

Abstract: According to the saw blade for process bogie structure characteristics,the use of Pro /E 3 d software based on the 3 d model,with ANSYS software,a static and modal analysis,obtained the stress pattern,structure deformation diagram and the former 6 order natural frequency and modal shape. The analysis results show that the node the maximum equivalent stress and the maximal displacement nodes are within the scope of the provisions,the data are meet the requirements,frame structure overall stiffness is better,frame has good static characteristic and dynamic characteristic,can meet the design requirements.And on this basis to frame was further optimized,so as to save materials,reduce cost.The theoretical basis is provided for the development of the process bogie .

Abstract: Composite foundation settlement is affected by many factors, and settlement data is a non-linear changing process with complexity, suddenness and progressive nature and so on. So we must analyze and predict the stability of the foundation settlement. Because empirical mode decomposition (EMD) provides a new way for foundation settlement prediction, we can extract modal signals associated with the foundation settlement mechanisms by decomposing the monitoring data of settlement by EMD and use the support vector machine ( Support Vector Machine, SVM) modal to predict the obtained signal, Calculation results of the modal synthesis and accumulation of foundation settlement, get the evolution of Change with the time of foundation settlement. Combined with the engineering example for the application ,shows that the prediction model has good effect in multi modality support vector, a high degree of agreement with the monitoring values, indicating that this method has a promotional value.

Abstract: By modeling of sugarcane leaf cutting off returning to field machinery chassis and loading, this paper simplifies reasonably several different conditions of the chassis to the two forms. The finite element is used for the solution of the problem by using ANSYS software, solving the node stress contour of the chassis. Compared the maximum stress in the most dangerous working conditions to the allowable stress of the material, the result verifies the chassis strength to meet the design requirements. According to the vibration of the chassis at work, analyzing the first sixth modal of the chassis, and comparing with excitation frequency shows that the design of the chassis avoids the excitation frequency, which does not cause resonance at work. The results show that the chassis meets the design requirements.

Abstract: To control the pure electric vehicle motors vibration and noise, the dynamic characteristics of the motor are analyzed. Dynamic characteristic include the natural frequency and response characteristics of different parts of the motors structural member. This paper uses three-dimensional software Pro/E modeling of the motor: By making appropriate assumptions and equivalent treatment of the motors stator, rotor core and coil winding, establish the finite element simulation model of the various components .Using the finite element analysis software Workbench analyzes the windings and motor model modal analysis, to get natural frequency of each mode. To make a modal analysis test, we can use hammering method done on the motor. By using real-time signal analyzer AWA6291 make spectral analysis of the motor online, comprehensive comparative analysis of the results and used to guide motor design.

Abstract: This paper takes a marine steam turbine control valve as the research object, studies the vibration response under pressure pulse excitation. First, the transient flow field analysis is made to obtain the time-domain information of the pressure pulsation; Followed by pressure pulsations fast Fourier transform into the frequency domain information, access to the load spectrum; Then modal analysis is studied to obtain the natural frequencies and mode shapes; Finally, based on the analysis of vibration modes, research vibration response and resonance problems of control valve. The study found that the vibration of control valve is strongly in low frequency excitation, but high-frequency excitation makes relatively little impacts on it; The diffuser and downstream of valve is the main area of generating vibration. Supported by the Fundamental Research Funds for the Central Universities (HEUCF140707).

Abstract: Motorcycle fender is one of the main components of motorcycle,fender structure directly affected it's comfort and security properties.In this paper, the finite element modeling and dynamic response were analyzed using NX 8.0, and found its natural frequencies and mode shapes. On the basis of the fender structure modeling on different road with the same speed, this paper investigated the several factors affect the vibration motorcycle and analyzed true fender of the motorcycle and did comparative analysis with the modal analysis results. It is helpful to the design of the fender structure and the estimation of the fender fracture. Key Words: Fender;finite element method;modal;Dynamic response