Wang Z.,University of Electronic Science and Technology of China |
Wang Z.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Zhang X.,University of Electronic Science and Technology of China |
Huang H.-Z.,University of Electronic Science and Technology of China |
Mourelatos Z.P.,Oakland University
Journal of Mechanical Design, Transactions of the ASME | Year: 2016
The failure rate of dynamic systems with random parameters is time-varying even for linear systems excited by a stationary random input. In this paper, we propose a simulation-based method to estimate two types (type I and type II) of time-varying failure rate of dynamic systems. The input stochastic processes are discretized in time and the trajectories of the output stochastic process are calculated. The time of interest is partitioned into a series of time intervals and the saddlepoint approximation (SPA) is employed to estimate the probability of failure in each interval. Type I follows the commonly used definition of failure rate. It is estimated at discrete time intervals using SPA and the correlation information from a properly selected time-dependent copula function. Type II is a proposed new concept of time-varying failure rate. It provides a way to predict the failure rate considering a virtual "good-as-old" repair action of repairable dynamic systems. The effectiveness of the proposed method is illustrated with a vehicle vibration example. © 2016 by ASME.
Libo C.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Wei W.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Zhang G.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body
Chinese Journal of Biomedical Engineering | Year: 2015
Based on CT scans, the C4-C5 cervical segment finite element model for 3-year old child was developed with accurate skeletal geometries and detailed anatomical structures of intervertebral disc. Grounded on biomechanical experiments published of adult cervical spine and the comparison of the data between adult and child, scaling methods were used to calculate the material parameters for 3-year old pediatric cervical spine. The model was validated under quasi-static and dynamic tensile, quasi-static flexion-extension, and lateral-bending as well as axial-rotation loadings. It is indicated that responses for the tensile simulations are consistent with those of the experiments, with the quasi-static tensile stiffness of 211. 8 N/mm, dynamic tensile ultimate failure force of 759. 9 N and ultimate failure displacement of 5. 08 mm in simulations. Responses for quasi-static bending simulations were within the standard deviation or corridor of the experiments, with the range of motion for extension 9.75°, flexion 9.29°, lateral-bending 3. 79° and axial-rotation 7.04°. It is indicated that this model is biofidelic enough to reflect the biomechanical properties of 3-year old pediatric C4-C5 cervical spine under quasi-static and dynamic tensile, as well as quasi-static flexion-extension, lateral bending and axial rotation loadings.
Cao L.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Chen H.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Ren X.,Pan Asia Technical Automotive Center |
Ouyang Z.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body
Applied Mechanics and Materials | Year: 2010
A new integrated child safety seat is presented in this paper. The seat is a two-mode seat for a motor vehicle cooperable with an adult seat belt assembly to provide two modes operation including an adult seat mode and a child seat mode. The seat locates in the center of the rear seat. The structure of the seat was designed in detail. The height of the booster of the seat can be adjusted continuously according to the seated shoulder height of the child passenger. The depth of booster cushion also can be changed according to the size of the passenger. The sled test with the seat was conducted. The seat simulation models with different booster heights were developed using MADYMO software and validated. Then, these models were used to study the performance of the seat in frontal impact. Some key parameters of the seat were studied in simulation test. The results of the test and simulation show that the seat can provide effective protection for the children aged from 3 to 10 years in frontal impact. © (2010) Trans Tech Publications.
Jiang C.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Liu L.-X.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Long X.-Y.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body
Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics | Year: 2013
A high efficient method is proposed to deal with reliability analysis of hybrid structures with random and interval variables. Response surface method in the traditional probability reliability analysis is applied to the hybrid uncertainty problem, combined Bucher design with vector projection method, a linear response surface is constructed, and then an efficient decoupling approach is used to solve an approximate hybrid reliability model which is created based on the response surface, after several times iteration, response surface is sufficiently close to the exact limit state function. Numerical examples are provided to demonstrate the effectiveness of the present method.
Wu Y.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Jiang C.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body
Jixie Qiangdu/Journal of Mechanical Strength | Year: 2014
Based on the probability-interval hybrid uncertainty model, a structural reliability analysis method considering fuzzy uncertainty is proposed. Here, fuzzy stochastic theory is adopted. Using the complementary function of membership function, the fuzzy random reliability model with interval variables is equivalently transformed into a mixture model only with random and interval variables, Then, the traditional method used to calculate the maximum failure probability with probability and interval variables is adopted to obtain the maximum fuzzy failure probability. Finally, three numerical examples and an engineering example are provided to demonstrate the effectiveness of the proposed method.
Deng Y.W.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Han W.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Yin L.,Hunan University
Advanced Materials Research | Year: 2013
A better understanding of the adsorption behaviors of hydrocarbons on adsorbent would help trap the hydrocarbons emitted from diesel engines during cold start period more efficiently. In this paper, the adsorption behaviors of hydrocarbons in LTA zeolite was studied using Grand Canonical Monte Carlo (GCMC) simulation. The adsorption isotherms and mass clouds are obtained for both pure component and binary mixtures under certain temperatures. The adsorption isotherms reveal that the average loading of ethylene and propylene has the similar trend. Both of them increase with the increase of pressure and decrease significantly with the increase of temperature. The binary mixtures show competitive adsorption behavior. Propylene is adsorbed much more strongly than ethylene in LTA zeolite. The obtained mass clouds show that propylene distributes in both the α cage and β cage of the LTA zeolite, while ethylene distributes mainly in the β cage of the LTA zeolite. © (2013) Trans Tech Publications, Switzerland.
Xue B.Y.,Southwest Jiaotong University |
Wu S.C.,Southwest Jiaotong University |
Wu S.C.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Zhang W.H.,Southwest Jiaotong University |
Liu G.R.,University of Cincinnati
International Journal of Computational Methods | Year: 2013
By smoothing, via various ways, the compatible strain fields of the standard finite element method (FEM) using the gradient smoothing technique, a family of smoothed FEMs (S-FEMs) has been developed recently. The S-FEM possesses the advantages of both mesh-free methods and the standard FEM and works well with triangular and tetrahedral background cells and elements. Intensive theoretical investigations have shown that the S-FEM models can achieve numerical solutions for many important properties, such as the upper bound solution in strain energy, free from volumetric locking, insensitive to the distortion of the background cells, super-accuracy and super-convergence in displacement or stress solutions or both. Engineering problems, including complex heat transfer problems, have also been analyzed with better accuracy and efficiency. This paper presents the general formulation of the S-FEM for thermal problems in one, two and three dimensions. To examine our formulation, some computational results are compared with those obtained using other established means. © 2013 World Scientific Publishing Company.
Liu D.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Mo X.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body
2011 International Conference on Consumer Electronics, Communications and Networks, CECNet 2011 - Proceedings | Year: 2011
The layout of a new type bus is different from the traditional bus, the change of the structure has considerable influence to the durability to the body, it's necessary to predict the fatigue life of vehicle body at the early stage of the design. In this paper, the finite element model of the vehicle including the body frame, chassis and tire was built by using the CAE technology Virtual Proving Ground, and the road excitation load is generated and its characteristic was verified using MATLAB. The VPG approach uses the realistic tire-road interactions and the explicit finite element code LS-DYNA to obtain the dynamic stress history of vehicle body, the fatigue life of the vehicle body was predicted by using the VPG fatigue tool. The analysis provides references for the structure design and modification of the vehicle body. © 2011 IEEE.
Chen X.,Jilin University |
Zhou J.L.,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body
Advanced Materials Research | Year: 2012
The 3-D digital models are established for two kinds of base styling of rearview cover. The compare analysis using Fluent model is based on the acoustic theory of computation. The results show that the average sound pressure level of up-raised rearview cover model is about 5 dB lower than that down-raised rearview cover model, and in all of the frequency range were apparently different. At the same time, the vortex of down-raised happened at the back location, which is more closer to the passenger's ear, and affect the car interior noise. The results of analysis will conduct the design of rearview styling effectively. © (2012) Trans Tech Publications, Switzerland.
Wang Y.L.,State key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Zhang B.J.,State key Laboratory of Advanced Design and Manufacturing for Vehicle Body |
Zhang N.,University of Technology, Sydney
Applied Mechanics and Materials | Year: 2013
This paper presents a full-car model of vehicle fitted with roll resistant specific HIS system in order to research the coordination of the main modals of sprung mass. Based on the transfer matrix method and state space method, the mechanical and hydraulic coupled multi-body dynamic equation is derived. The eigenvalue and eigenvector is solved by eigenvalue iteration identification method of frequency-dependent characteristic. By discussing the characteristic of the damping components which are the dominant parameters of the coupled system, an innovative design approach of damping components of the HIS system is proposed. Finally, comparison of vehicle vibration is carried out between vehicle with traditional suspension and that fitted with roll resistant specific HIS system. The obtained result indicates that with the proposed design approach of damping components, the roll resistant specific HIS system can promote the capacity of anti-rollover specific observably with reasonable comfort performance. © (2013) Trans Tech Publications, Switzerland.