Research of High Speed Train Carbody Structure Vibration Behaviors and Structure Fatigue Strength Characteristic Technology

2012 ◽  
Vol 544 ◽  
pp. 256-261
Author(s):  
Bing Rong Miao ◽  
Wei Hua Zhang ◽  
G.H. Huang ◽  
S.C. Wu ◽  
Yong Xiang Zhao

The hybrid simulation method based on Multibody Simulation (MBS) and finite element method (FEM) were proposed here and applied to study the relation between carbody structure vibration behaviors and structure fatigue strength characteristic. The detailed steps include: Firstly, rigid-flexible couple vehicle multibody system dynamic model was created and performed to obtain the load time histories corresponded to the typical load cases. Secondly, the carbody structure stresses was calculated through Finite Element (FE) quasi-static stress method. Finally, with the material fatigue property and some uncertainty factors, carbody fatigue damage distribution and life was calculated and evaluated. And the conclusions can be understood that the mechanism between the full vehicle dynamic property and structure damage distribution. The results are also shown that the hybrid simulation technology could be applied into the carbody structure fatigue design.

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Weiyuan Dou ◽  
Lele Zhang ◽  
Haifeng Chang ◽  
Haifeng Zhang ◽  
Changqing Liu

AbstractThe cast aluminum beam is a key structure for carrying the body-hung traction motor of a high-speed train; its fatigue property is fundamental for predicting the residual life and service mileage of the structure. To characterize the structural fatigue property, a finite element-based method is developed to compute the stress concentration factor, which is used to obtain the structural fatigue strength reduction factors. A full-scale fatigue test on the cast aluminum beam is designed and implemented for up to ten million cycles, and the corresponding finite element model of the beam is validated using the measured data of the gauges. The results show that the maximum stress concentration occurs at the fillet of the supporting seat, where the structural fatigue strength reduction factor is 2.45 and the calculated fatigue limit is 35.4 MPa. Moreover, no surface cracks are detected using the liquid penetrant test. Both the experimental and simulation results indicate that the cast aluminum beam can satisfy the service life requirements under the designed loading conditions.


2011 ◽  
Vol 188 ◽  
pp. 216-219 ◽  
Author(s):  
M.H. Wang ◽  
Zhong Hai Liu ◽  
Hu Jun Wang

In order to improve machined surface quality and reduce the deformation, the residual stress involved in cutting titanium alloy was studied under different cutting speed and cutting depth by finite element simulation method. The results indicate that the increase of cutting speed and cutting depth are helpful to the surface residual compressive stress generating. However the increase of cutting speed also leads to the increase of surface residual tensile stress, the effect degree is relatively small. It is required to select higher cutting speed and smaller cutting depth to improve the surface stress state and reduce the unexpected distortion.


2012 ◽  
Vol 499 ◽  
pp. 39-44
Author(s):  
L. Yan ◽  
Feng Jiang ◽  
Y.M. Rong

This paper presented a finite element simulation model for the analysis of AISI D2 orthogonal cutting process using TiAlN coated inserts. Firstly, AISI D2 material constitutive model was built based on power law model, which was used in the FEM codes to describe the effect of strain, strain rate and temperature on the material flow stress. In modeling the chip formation, a damage model was employed to predict the chip separation. Then cutting edge radius and thickness of TiAlN coating of cutting tool were measured by SEM. Friction coefficients of cutting tool against AISI D2 steel were obtained by ball-on-plate friction tests on UMT-2 high speed tribometer. Finally, finite element simulations of AISI D2 orthogonal cutting processes were performed using AdvantedgeTM software. The simulated results of cutting forces and chip morphology showed good agreement with the experimental results, which validated the reliability of the cutting process simulation method.


Author(s):  
Yaohui Lu ◽  
Dewen Zhang ◽  
Heyan Zheng ◽  
Chuan Lu ◽  
Tianli Chen ◽  
...  

When two high-speed trains pass through a tunnel, the aerodynamic changes are more complex and drastic than in open air owing to the interference of the tunnel wall and the entry effect. The impact on the carbody fatigue strength is very significant in the fatigue reliability design of the carbody. In this paper, the sequential coupling method was used for the first time to study the effect of pressure waves on the fatigue strength in a large-scale and complex carbody structure. The computational fluid dynamics method was used to calculate and analyze the aerodynamic pressure wave of the intersection of the trains in a long and short tunnel. A full-scale finite element shell model of the carbody structure was established. Then, the time integration method was used to convert the transient pressure wave into the aerodynamic loads bearing by the side wall of the carbody. The inhomogeneous stress concentrations at the restraint points were eliminated by the inertial release method; moreover, a finite element analysis of the carbody was carried out under the combined aerodynamic and mechanical loads. The Goodman fatigue strength curve of the aluminum alloy carbody was drawn. The influence of the aerodynamic load on the fatigue strength of the vehicle body was analyzed and compared under the entry effect of the short tunnel. The results show that the aerodynamic load of the short tunnel has a significant impact on the fatigue strength of the carbody owing to the train's entry effect. The safety factor of the fatigue strength is 15% less than that of the long tunnel aerodynamic load. In this paper, computational fluid dynamics and finite element method were used to analyze and evaluate the impact of the pressure wave on the fatigue strength of the carbody, which is of great reference value in the structural design of the carbody subjected to complex aerodynamic loads.


2015 ◽  
Vol 1089 ◽  
pp. 377-380
Author(s):  
Lin Lin Guo ◽  
Guang Hui Li ◽  
Ning Xia Yin ◽  
Guang Yu Tan

The physical friction system model was established between the tool and the chip based on the analysis of tri-bological behavior of high speed milling process of the end mill. The finite element simulation method was employed to study the tool-chip friction model, and the two-dimensional(2D) finite element model of milling was created. The numerical results revealed the chip morphology, stress and temperature distribution of the tool-chip contact surface. The tool temperature field distribution provided supports for tool-chip friction state theory and the 3D milling model.


2018 ◽  
Vol 9 (4) ◽  
pp. 548-559
Author(s):  
Hongxing Jia ◽  
Shizhu Tian ◽  
Shuangjiang Li ◽  
Weiyi Wu ◽  
Xinjiang Cai

Purpose Hybrid simulation, which is a general technique for obtaining the seismic response of an entire structure, is an improvement of the traditional seismic test technique. In order to improve the analysis accuracy of the numerical substructure in hybrid simulation, the purpose of this paper is to propose an innovative hybrid simulation technique. The technique combines the multi-scale finite element (MFE) analysis method and hybrid simulation method with the objective of achieving the balance between the accuracy and efficiency for the numerical substructure simulation. Design/methodology/approach To achieve this goal, a hybrid simulation system is established based on the MTS servo control system to develop a hybrid analysis model using an MFE model. Moreover, in order to verify the efficiency of the technique, the hybrid simulation of a three-storey benchmark structure is conducted. In this simulation, a ductile column—represented by a half-scale scale specimen—is selected as the experimental element, meanwhile the rest of the frame is modelled as microscopic and macroscopic elements in the Abaqus software simultaneously. Finally, to demonstrate the stability and accuracy of the proposed technique, the seismic response of the target structure obtained via hybrid simulation using the MFE model is compared with that of the numerical simulation. Findings First, the use of the hybrid simulation with the MFE model yields results similar to those obtained by the fine finite element (FE) model using solid elements without adding excessive computing burden, thus advancing the application of the hybrid simulation in large complex structures. Moreover, the proposed hybrid simulation is found to be more versatile in structural seismic analysis than other techniques. Second, the hybrid simulation system developed in this paper can perform hybrid simulation with the MFE model as well as handle the integration and coupling of the experimental elements with the numerical substructure, which consists of the macro- and micro-level elements. Third, conducting the hybrid simulation by applying earthquake motion to simulate seismic structural behaviour is feasible by using Abaqus to model the numerical substructure and harmonise the boundary connections between three different scale elements. Research limitations/implications In terms of the implementation of the hybrid simulation with the MFE model, this work is helpful to advance the hybrid simulation method in the structural experiment field. Nevertheless, there is still a need to refine and enhance the current technique, especially when the hybrid simulation is used in real complex engineering structures, having numerous micro-level elements. A large number of these elements may render the relevant hybrid simulations unattainable because the time consumed in the numeral calculations can become excessive, making the testing of the loading system almost difficult to run smoothly. Practical implications The MFE model is implemented in hybrid simulation, enabling to overcome the problems related to the testing accuracy caused by the numerical substructure simplifications using only macro-level elements. Originality/value This paper is the first to recognise the advantage of the MFE analysis method in hybrid simulation and propose an innovative hybrid simulation technique, combining the MFE analysis method with hybrid simulation method to strike a delicate balance between the accuracy and efficiency of the numerical substructure simulation in hybrid simulation. With the help of the coordinated analysis of FEs at different scales, not only the accuracy and reliability of the overall seismic analysis of the structure is improved, but the computational cost can be restrained to ensure the efficiency of hybrid simulation.


Author(s):  
Xu Jia ◽  
Zi-wen Zhang ◽  
Chen Ling ◽  
Xu-ping Lu ◽  
Rong Jiang ◽  
...  

In this study, high-speed ballistic impact tests were conducted on GH4169 alloy samples with the aeroengine compressor blade leading edge feature to simulate the notch-type foreign object damages (FOD). Macroscopic and microscopic characterization of FOD and high cycle fatigue tests were performed to investigate the effect of FOD depth on GH4169 alloy fatigue strength along with numerical analysis using Kitagawa-Takahashi diagram. Results show the incident side of notch-type FOD is relatively smooth, whereas the exit side is rugged. The FOD depth ranges from 0.18mm to 1.33mm, and the fatigue strength of damaged samples is 37.93%~97.04% of the undamaged samples. As FOD depth increases, damage length, material losses and stress concentration coefficient of the FOD increase significantly along with the increasing adiabatic shear bands, micro voids and cracks, resulting in fatigue strength reduction. Numerical analysis indicates that the Kitagawa-Takahashi diagram can provide a basic model for the design of FOD tolerance.


2013 ◽  
Vol 274 ◽  
pp. 45-48 ◽  
Author(s):  
Hong Mei Li ◽  
Yan Xuan ◽  
Lan Wang ◽  
Yan Liang Li ◽  
Xing Fang ◽  
...  

Based on finite volume method of finite element method, the aerodynamics models of the train passing through bridge noise barriers (high respectively, for 2.15m, 1.93m) and the subgrade (high respectively, for 2.95m,3.95m) noise barriers is established by large commercial fluid dynamics calculation software. The three dimensional transient outflow field is numerical simulated by applying dynamic mesh technology and large eddy simulation method (LES) for the train passing through noise barriers. The extreme value, schedule curve and pressure cloud contour of fluctuating wind pressures of the different height noise barriers on bridge and roadbed are acquired for 300 ~ 420 km/h different speeds. Extreme values of fluctuating wind pressures product by trains with different speeds are contrast analyzed. The simulation results are very close to the experimental data, proves the validity and feasibility of the finite element model and the accuracy of the parameters. This research provides the theory support to the structural design of the noise barriers and can effectively guide the structural design of the noise barriers.


2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Daoyun Chen

Some crucial loads that current strength design specifications have not taken into account are also considered when assessing the strength of a bogie frame. Calculation methods of these loads come from load analysis. Finite element simulation and fatigue test rig have been used to assess static strength and fatigue strength of a bogie frame. In addition to the two methods, actual running test is also used to assess bogie frame fatigue strength. In finite element simulation method, endurance limit and modified Goodman fatigue limit diagram are two important tools to judge whether fatigue strength of a bogie frame meets requirement. In actual running test method, Miner linear cumulative damage rule is used to assess bogie frame fatigue strength.


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