A system methodology for optimization design of the structural crashworthiness of a vehicle subjected to a high-speed frontal crash

2017 ◽  
Vol 50 (4) ◽  
pp. 634-650 ◽  
Author(s):  
Liang Xia ◽  
Weiguo Liu ◽  
Xiaojiang Lv ◽  
Xianguang Gu
Author(s):  
Zijian Guo ◽  
Tanghong Liu ◽  
Wenhui Li ◽  
Yutao Xia

The present work focuses on the aerodynamic problems resulting from a high-speed train (HST) passing through a tunnel. Numerical simulations were employed to obtain the numerical results, and they were verified by a moving-model test. Two responses, [Formula: see text] (coefficient of the peak-to-peak pressure of a single fluctuation) and[Formula: see text] (pressure value of micro-pressure wave), were studied with regard to the three building parameters of the portal-hat buffer structure of the tunnel entrance and exit. The MOPSO (multi-objective particle swarm optimization) method was employed to solve the optimization problem in order to find the minimum [Formula: see text] and[Formula: see text]. Results showed that the effects of the three design parameters on [Formula: see text] were not monotonous, and the influences of[Formula: see text] (the oblique angle of the portal) and [Formula: see text] (the height of the hat structure) were more significant than that of[Formula: see text] (the angle between the vertical line of the portal and the hat). Monotonically decreasing responses were found in [Formula: see text] for [Formula: see text] and[Formula: see text]. The Pareto front of [Formula: see text] and[Formula: see text]was obtained. The ideal single-objective optimums for each response located at the ends of the Pareto front had values of 1.0560 for [Formula: see text] and 101.8 Pa for[Formula: see text].


2013 ◽  
Vol 745-746 ◽  
pp. 197-202 ◽  
Author(s):  
Chang Qing Ye ◽  
Zi Gang Deng ◽  
Jia Su Wang

t was theoretically and experimentally proved that High Temperature Superconducting (HTS) Maglev had huge potential employment in rail transportation and high speed launch system. This had attracted great research interests in practical engineering. The optimization design was one of the most important works in the application of the HTS Maglev. As the NdFeB permanent magnet and HTS materials prices increased constantly, the design optimization of the permanent guideway (PMG) of HTS maglev became one of the indispensable works to decrease the cost of the application. This paper first reviewed four types of PMGs used by the HTS Maglev, then disucssed their structures and magnetic fields. Finally, the optimization methods of these four PMGs were compared. It was suggested that with better optimization methods, the levitation performance within a limit cost got better. That would be helpful to the future numerical optimization of the PMG of the HTS maglev.


2021 ◽  
Vol 16 (5) ◽  
pp. 773-780
Author(s):  
Bing-Jie Li ◽  
Zhen-Song Li ◽  
Yan-Ping Zhao ◽  
Zheng-Wang Li ◽  
Min Miao

The signal integrity (SI) analysis of a high-speed signal interconnect channel composed of through silicon vias (TSVs) and horizontal re-distribution layers (RDL) is carried out, and the problems of SI, such as transmission loss, crosstalk and coupling effect in the transmission channel, are analyzed and studied. These signal integrity issues are considered in this paper, a signal interconnect channel model is proposed and the equivalent circuit model is deduced as well. Compared with the traditional one, this interconnect channel model has better performance in SI. Further sweep frequency analysis is carried out for different material parameters to achieve signal transmission performance optimization aimed at this model. Test samples of the proposed signal interconnect channel model are designed and fabricated according to the process index, and measured to verify the actual transmission performance. The design and optimization rule of high-speed signal interconnect channel are summarized which proved that the proposed structure has more advantages in signal transmission performance, and has important guiding significance for practical design.


Author(s):  
Deqi Yu ◽  
Xiaojun Zhang ◽  
Jiandao Yang ◽  
Kai Cheng ◽  
Weilin Shu ◽  
...  

Fir-tree root and groove profiles are widely used in gas turbine and steam turbine. Normally, the fir-tree root and groove are characterized with straight line, arc or even elliptic fillet and splines, then the parameters of these features were defined as design variables to perform root profile optimization. In ultra-long blades of CCPP and nuclear steam turbines and high-speed blades of industrial steam turbine blades, both the root and groove strength are the key challenges during the design process. Especially, in industrial steam turbines, the geometry of blade is very small but the operation velocity is very high and the blade suffers stress concentration severely. In this paper, two methods for geometry configuration and relevant optimization programs are described. The first one is feature-based using straight lines and arcs to configure the fir-tree root and groove geometry and genetic algorithm for optimization. This method is quite fit for wholly new root and groove design. And the second local optimization method is based on B-splines to configure the geometry where the local stress concentration occurs and the relevant optimization algorithm is used for optimization. Also, several cases are studied as comparison by using the optimization design platform. It can be used not only in steam turbines but also in gas turbines.


Author(s):  
Guohai Jia ◽  
Guoshuai Tian ◽  
Zicheng Gao ◽  
Dan Huang ◽  
Wei Li ◽  
...  

Abstract Cyclone venturi dryer is suitable for drying materials with large particle size and wide distribution. The working process of cyclone venturi dryer is a very complicated three-dimensional and turbulent motion, so it is difficult to be studied theoretically and experimentally. In order to study the internal flow characteristics of the biomass particle cyclone venturi dryer, the computational fluid dynamics (CFD) software was used to simulate the gas-solid two-phase flow field inside the cyclone venturi dryer. The continuous phase adopts the Realizable k-ε turbulence model and the particle phase is discrete. The effects of different injection volume on the pressure, velocity, and temperature fields inside a cyclone venturi dryer were analyzed. The results showed that the maximum pressure drop and velocity change inside the dryer were at the venturi pipe. The wet material of the cyclone venturi dryer was inhaled into the venturi contraction tube by the negative pressure formed after the highspeed airflow was ejected, thus the mixture was completed in the venturi throat. The wood debris material was mixed with the high-speed hot gas flow in the venturi throat and then sprayed into the diffusion pipe. In the diffusion pipe of venturi, the heat and mass transfer process of wet wood debris and heat flow in venturi diffusion tube was completed. It is in good agreement with the simulation results. This study can provide a reference for the optimization design of the related cyclone venturi dryer structure.


2020 ◽  
Vol 47 (10) ◽  
pp. 1006003
Author(s):  
甄政 Zhen Zheng ◽  
郝然 Hao Ran ◽  
邢东 Xing Dong ◽  
冯志红 Feng Zhihong ◽  
金尚忠 Jin Shangzhong

2013 ◽  
Vol 312 ◽  
pp. 106-109
Author(s):  
Run Xie ◽  
Ji Fei Cai ◽  
Jia Cong Chen

For paper forward unit of the current forward type flute laminating machine, the contact surface of the paper forward unit may damage paper during high speed paper forwarding. In view of this phenomenon, a solution is proposed through the study on the feeding unit of the flute laminating machine. In this paper, the corresponding sprocket driveshaft is controlled by a servo motor to slowly forward paper at the beginning and accelerate its forwarding speed gradually, until the entire feeding process is completed. In this way, the problem of paper pile-up and damages during the paper forwarding process can be solved, while matching backing paper feeding, so as to improve the feeding accuracy of the full-automatic flute laminating machine and hence its laminating accuracy.


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