Effects of Cont Rail Joint Type on Bus Rollover Crashworthiness

2014 ◽  
Vol 945-949 ◽  
pp. 156-161
Author(s):  
Han Chi Hong ◽  
Hong Wu Huang

Three finite element models of bus with difference types of cant rail joint were developed and the rollover crashworthiness of buses was simulated by LS_DYNA according to ECE R66. The calculation technique was validated by the tests of three separate specimens, which were extracted from the bus superstructure. The velocity of bus just before impact for rollover, were calculated using ADAMS software and then used as initial condition for the LS_DYNA analysis. No intrusion was found in the residual space of three bus models during rollover test simulation. The energy absorbing capacity and distortion configuration were investigated. The simulation results shown that the cont rail joint structure played an important part in energy absorbing during bus rollover accident, and would contribute to some design guidelines for bus rollover crashworthiness.

Author(s):  
Haolei Mou ◽  
Zhenyu Feng ◽  
Jiang Xie ◽  
Jun Zou ◽  
Kun Zhou

AbstractTo analysis the failure and energy absorption of carbon fiber reinforced polymer (CFRP) thin-walled square tube, the quasi-static axial compression loading tests are conducted for [±45]3s square tube, and the square tube after test is scanned to further investigate the failure mechanism. Three different finite element models, i.e. single-layer shell model, multi-layer shell model and stacked shell mode, are developed by using the Puck 2000 matrix failure criterion and Yamada Sun fiber failure criterion, and three models are verified and compared according to the experimental energy absorption metrics. The experimental and simulation results show that the failure mode of [±45]3s square tube is the local buckling failure mode, and the energy are absorbed mainly by intralaminar and interlaminar delamination, fiber elastic deformation, fiber debonding and fracture, matrix deformation cracking and longitudinal crack propagation. Three different finite element models can reproduce the collapse behaviours of [±45]3s square tube to some extent, but the stacked shell model can better reproduce the failure mode, and the difference of specific energy absorption (SEA) is minimum, which shows the numerical simulation results are in better agreement with the test results.


2013 ◽  
Vol 718-720 ◽  
pp. 1673-1676
Author(s):  
Yun Chao Wang ◽  
Wen Jie Pang ◽  
Mei Zhou

Digging performances of excavator is a key important index for evaluation of excavator. It is a very complex and heavy work to compute digging performance of excavator. So a compact hydraulic excavator model was built by ADAMS software. The theoretical maximum tool force of excavator was analyzed. For bucket digging mode, the maximum tool force were analyzed for boom cylinder seven positions during the whole working range and the effect of different factors were discussed. The practical maximum tool force was gained. The actual tool force variations were found through the analysis of simulation results. It provides the basis for design and improvement of excavator.


2014 ◽  
Vol 945-949 ◽  
pp. 1421-1425
Author(s):  
Xiu Qing Hao

Take typical parallel mechanism 3PTT as research subject, its inverse kinematic analysis solution was gotten. Dynamic model of the mechanism was established by Newton-Euler method, and the force and torque equations were derived. Dynamic simulation of 3PTT parallel mechanism was done by using ADAMS software, and simulation results have verified the correctness of the theoretical conclusions.


2009 ◽  
Vol 419-420 ◽  
pp. 45-48 ◽  
Author(s):  
Wen Hsiang Hsieh ◽  
Chia Heng Tsai

The purpose of this study is to present a novel concept for inline vibrating conveyors, and verify its feasibility by kinematic simulation. First, new conveyor is presented, and its merits are discussed. Then, its kinematically equivalent linkage is described. Moreover, the kinematic dimensions are investigated from its geometry. Finally, the solid model for the proposed design is established, then kinematic simulation is performed by ADAMS software. The simulation results indicate that the proposed new design can effectively advance the workpiece.


2014 ◽  
Vol 529 ◽  
pp. 102-107
Author(s):  
Hai Bo Luo ◽  
Ying Yan ◽  
Xiang Ji Meng ◽  
Tao Tao Zhang ◽  
Zu Dian Liang

A 7.8m/s vertical drop simulate of a full composite fuselage section was conducted with energy-absorbing floor to evaluate the crashworthiness features of the fuselage section and to predict its dynamic response to dummies in future. The 1.52m diameter fuselage section consists of a high strength upper fuselage frame, one stiff structural floor and an energy-absorbing subfloor constructed of Rohacell foam blocks. The experimental data from literature [6] were analyzed and correlated with predictions from an impact simulation developed using the nonlinear explicit transient dynamic computer code MSC.Dytran. The simulated average acceleration did not exceed 13g, by contrast with experimental results, whose relative error is less than 11%. The numerical simulation results agree with experiments well.


2015 ◽  
Vol 656-657 ◽  
pp. 694-699
Author(s):  
Xin Liao ◽  
Jian Run Zhang ◽  
Dong Lu

In this study, a non-linear finite element model for a simplified single-bolted joint structure model is built. Static analysis on the structure under different shear force and pretension effect is done, and the non-linear contact behavior is analyzed. Through comparing datum, it is found that interface area of each bolted joint region can be described an annular region around bolt hole, whose outer radius has increased by 85% compared with radius of bolt hole. Also, the frequency responses of the multi-bolted joint structure under sinusoidal excitation are investigated. Simulation results show that the resonance regions basically remain unchanged in different pretension effect and the largest amplitude will increase with the increasing preloads. Finally, the vibration experiments are conducted. Interface nonlinear affect dynamic stiffness considerably. The test results illustrate that dynamic behaviors of bolted joint agree with the simulation results and the proposed non-linear contact model was reasonable.


2017 ◽  
Vol 2 (3) ◽  
pp. 235
Author(s):  
Massimiliano Laddomada ◽  
Bartolo Scanavino

The aim of this paper is twofold. On one hand, it presents the results of the search for good punctured systematicrecursive convolutional encoders suitable for application in serially concatenated convolutional codes (SCCCs) operating in two different target regions: at low-to moderate signal-to-noise ratios (SNRs), i.e., in the so called waterfall region, and at high SNRs. On the other hand, it provides some useful design guidelines for choosing the constituent encoders in an SCCC. The results of the search for good SCCCs operating in the waterfall region rely upon an effective algorithm, based on density evolution technique, first proposed in a companion paper. Good punctured SCCCs were obtained through considerationsdeduced by the behaviour of the bit error probability of an SCCC for high values of both SNR and interleaver length, i.e., through asymptotic considerations. The mother codes in the serial concatenation are rate 1/2 recursive convolutional encoders (RCC) found by an exhaustive search for encoders tailored to SCCC schemes, using two different selection criteria. Extensive tables of optimized puncturing patterns for various mother codes and SCCCs are presented along with sample simulation results.


Author(s):  
Lý Hùng Anh ◽  
Nguyễn Phụ Thượng Lưu ◽  
Nguyễn Thiên Phú ◽  
Trần Đình Nhật

The experimental method used in a frontal crash of cars costs much time and expense. Therefore, numerical simulation in crashworthiness is widely applied in the world. The completed car models contain a lot of parts which provided complicated structure, especially the rear of car models do not contribute to behavior of frontal crash which usually evaluates injuries of pedestrian or motorcyclist. In order to save time and resources, a simplification of the car models for research simulations is essential with the goal of reducing approximately 50% of car model elements and nodes. This study aims to construct the finite element models of front structures of vehicle based on the original finite element models. Those new car models must be maintained important values such as mass and center of gravity position. By using condition boundaries, inertia moment is kept unchanged on new model. The original car models, which are provided by the National Crash Analysis Center (NCAC), validated by using results from experimental crash tests. The modified (simplistic) vehicle FE models are validated by comparing simulation results with experimental data and simulation results of the original vehicle finite element models. LS-Dyna software provides convenient tools and very strong to modify finite element model. There are six car models reconstructed in this research, including 1 Pick-up, 2 SUV and 3 Sedan. Because car models were not the main object to evaluate in a crash, energy and behavior of frontal part have the most important role. As a result, six simplified car models gave reasonable outcomes and reduced significantly the number of nodes and elements. Therefore, the simulation time is also reduced a lot. Simplified car models can be applied to the upcoming frontal simulations.


2014 ◽  
Vol 940 ◽  
pp. 132-135 ◽  
Author(s):  
Yi Fan Zhao ◽  
Ling Sha ◽  
Yi Zhu

Established the dynamics simulation analysis model of crane hoisting mechanism based on the theory of dynamics in Adams software, and then through the three dimensional model of lifting mechanism dynamics entities, the constraints, load, drive can be added, the motion law can be defined to simulation analysis the change of the force of wire rope, the change of displacement, velocity and acceleration of lifting weight in the lifting process. On the basis of the simulation results, it can make a great improvement for the structure of crane and provide a meaningful theoretical reference for the hoisting machinery innovation design.


Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4611 ◽  
Author(s):  
Su Y. Choi ◽  
Chang Y. Lee ◽  
Jung M. Jo ◽  
Jae H. Choe ◽  
Ye Jun Oh ◽  
...  

Sub-sonic linear synchronous motors (LSMs) with high-temperature superconducting (HTS) magnets, which aim to accelerate to a velocity of 1200 km/h in the near-vacuum tubes of 0.001 atm for the Hyperloop, are newly introduced in this paper. By the virtue of the combination of LSMs and electrodynamic suspensions (EDSs) with HTS magnets, a large air-gap of 24 cm, low magnetic resistance forces of below 2 kN, and the efficient as well as practical design of propulsion power supply systems of around 10 MVA could be guaranteed at a sub-sonic velocity. The characteristics of the proposed LSMs with HTS magnets, in addition, are widely analyzed with theories and simulation results. Optimal design methods for LSMs and inverters, which account for more than half of the total construction cost, are introduced with design guidelines and examples for the commercialization version of the Hyperloop. At the end of the paper, in order to verify the proposed design models of the sub-sonic LSMs, two different test-beds—i.e., 6 m long static and 20 m long dynamic propulsion test-beds—are fabricated, and it is found that the experimental results are well matched with proposed design models as well as simulation results; therefore, the design methods constitute guidelines for the design of sub-sonic LSMs for the Hyperloop.


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