The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Qing Li - One of the best experts on this subject based on the ideXlab platform.
-
Crashworthiness analysis and optimization of fourier varying section tubes
International Journal of Non-linear Mechanics, 2017Co-Authors: Shengyin Wu, Guangyao Li, Xin Wu, Qing LiAbstract:Abstract Thin-walled structures are widely used as energy absorption devices for their proven advantages on lightweight and Crashworthiness. However, a majority of studies have being focus on exploring separately the Crashworthiness of the thin-walled structure with a specific geometric section, such as circular, square, hexagon, octagon etc., and little research has investigated the relationship of Crashworthiness among thin-walled structures with different sections systematically. This paper utilizes Fourier series expansion to generate a series of novel sectional configurations, namely Fourier varying sectional tubes (FVSTs), to look into their advantages of Crashworthiness, thereby developing some FVSTs with highest possible energy absorption capacity. Based on the validated finite element (FE) models, parametric analysis is conducted to investigate the effects of cross-sectional configuration, perimeter and thickness of FVSTs on collapse mode and energy absorption. The results showed that the collapse modes of FVSTs are fairly sensitive to cross-sectional configuration, perimeter and wall thickness. Of these FVSTs generated, the highest specific energy absorption (SEA) increases 77.54% by increasing perimeter and 69.73% by decreasing wall thickness. Finally, a discrete optimization based on the orthogonal arrays is conducted to obtain the optimal FVST for maximizing SEA under the constraint of the initial peak crushing force (IPCF). The optimized FVSTs are of superior Crashworthiness and great potential as an energy absorber.
-
On design optimization for structural Crashworthiness and its state of the art
Structural and Multidisciplinary Optimization, 2017Co-Authors: Jianguang Fang, Na Qiu, Nam H. Kim, Guangyong Sun, Qing LiAbstract:Optimization for structural Crashworthiness and energy absorption has become an important topic of research attributable to its proven benefits to public safety and social economy. This paper provides a comprehensive review of the important studies on design optimization for structural Crashworthiness and energy absorption. First, the design criteria used in Crashworthiness and energy absorption are reviewed and the surrogate modeling to evaluate these criteria is discussed. Second, multiobjective optimization, optimization under uncertainties and topology optimization are reviewed from concepts, algorithms to applications in relation to Crashworthiness. Third, the crashworthy structures are summarized, from generically novel structural configurations to industrial applications. Finally, some conclusions and recommendations are provided to enable academia and industry to become more aware of the available capabilities and recent developments in design optimization for structural Crashworthiness and energy absorption.
-
sensitivity analysis and reliability based design optimization for high strength steel tailor welded thin walled structures under Crashworthiness
Thin-walled Structures, 2016Co-Authors: Xueguan Song, Qing LiAbstract:Abstract Tailor welded blanks (TWB) have been widely applied in automobile industry. This paper firstly conducts experimental tests to investigate the Crashworthiness of three different types of TWB hat-shaped structures. Their combinations provide three representative TWB configurations: namely the same material grade with different wall thicknesses; different grades with the same thickness, different material grades with different thicknesses, respectively. Secondly, the finite element (FE) models corresponding to each of the samples are established to perform Crashworthiness analysis. It is exhibited that the FE simulations are in good agreement with the experimental tests. Thirdly, the surrogate models are constructed to approximate the Crashworthiness responses of these TWB structures. Fourthly, a sensitivity analysis is conducted to explore the effects of the weld line location, wall thickness and material properties for each segment of TWB structures subject to crashing load. The results showed that the wall thickness is most sensitive to the Crashworthiness of TWB structures. Finally, reliability based design optimization is carried out by taking into account the uncertainties in the TWB configuration. The results demonstrate that the optimized TWB tubes are capable to improve energy absorption as well as enhance the reliability, potentially being an ideal structure for Crashworthiness.
-
on design of multi cell thin wall structures for Crashworthiness
International Journal of Impact Engineering, 2016Co-Authors: Suzhen Wu, Guangyao Li, Gang Zheng, Qing LiAbstract:Abstract Multi-cell thin-wall structures have drawn increasing attention and been widely applied in automotive and aerospace industries for their significant advantages in high energy absorption and lightweight. The number of cells and the topological configurations of the multi-cell thin-wall structures have a significant effect on the Crashworthiness. In order to investigate the effect of the number of cells and the topological configurations of multi-cell structures on their Crashworthiness characteristics, this paper first sets up the simulation models of multi-cell tubes and verifies their accuracy with the quasi-static and dynamic impact experiments. Second, it compares the energy absorption characteristics of the multi-cell structures with different numbers of cells and topological configurations under dynamic impact condition using finite element analysis (FEA). The results show that the mean crushing force (MFC) and specific energy absorption (SEA) increase with the increase in the number of cells of the multi-cell tubes, among which the five-cell tube has the best energy absorption characteristics. Third, a parametric study is carried out to investigate the effects of wall thickness and topology configurations on the Crashworthiness of five-cell tubes. Finally, the multiobjective Non-dominated Sorting Genetic Algorithm (NSGA-II) is used to further optimize the five-cell tube for maximizing specific energy absorption and minimizing peak crushing force (PCF). The optimal five-cell tube has excellent Crashworthiness and is a potential energy absorber.
-
how does negative poisson s ratio of foam filler affect Crashworthiness
Materials & Design, 2015Co-Authors: Zhidan Zhang, Qing LiAbstract:Abstract As an effective candidate for enhancing energy absorption, a range of foam materials have gained considerable popularity, in which the density, Young’s modulus and plasticity of foam materials are considered critical to Crashworthiness. Relatively speaking, less attention has been paid to the roles played by the Poisson’s ratio of foam or cellular materials. More importantly, the interaction between different Poisson’s ratios and thin-walled structures has been a critical yet under-studied issue. This paper aims to explore the effects of negative, zero and positive Poisson’s ratio of auxetic foams, ranging from −1 to 0.5, on structural Crashworthiness and seek optimal design for different foam-filled square, circular and conic tubes. In this study the specific energy absorption (SEA) and mean crushing force (MCF) are taken as the objective functions by using mathematical regression analysis. The sequential quadratic programming (SQP) and the Non-dominated Sorting Genetic Algorithm II (NSGA-II) are employed for single and multiobjective design of foam-filled tubes with different Poisson’s ratios, respectively. The optimal Poisson’s ratio is obtained for these three different types of foam-filled tubes. By comparison we found that the Crashworthiness of foam filled conic tube is the best, followed by circular and then squared tubes. The study provides new insights into material selection and design with a more favorable Poisson’s ratio for Crashworthiness.
Guangyao Li - One of the best experts on this subject based on the ideXlab platform.
-
Crashworthiness analysis and optimization of fourier varying section tubes
International Journal of Non-linear Mechanics, 2017Co-Authors: Shengyin Wu, Guangyao Li, Xin Wu, Qing LiAbstract:Abstract Thin-walled structures are widely used as energy absorption devices for their proven advantages on lightweight and Crashworthiness. However, a majority of studies have being focus on exploring separately the Crashworthiness of the thin-walled structure with a specific geometric section, such as circular, square, hexagon, octagon etc., and little research has investigated the relationship of Crashworthiness among thin-walled structures with different sections systematically. This paper utilizes Fourier series expansion to generate a series of novel sectional configurations, namely Fourier varying sectional tubes (FVSTs), to look into their advantages of Crashworthiness, thereby developing some FVSTs with highest possible energy absorption capacity. Based on the validated finite element (FE) models, parametric analysis is conducted to investigate the effects of cross-sectional configuration, perimeter and thickness of FVSTs on collapse mode and energy absorption. The results showed that the collapse modes of FVSTs are fairly sensitive to cross-sectional configuration, perimeter and wall thickness. Of these FVSTs generated, the highest specific energy absorption (SEA) increases 77.54% by increasing perimeter and 69.73% by decreasing wall thickness. Finally, a discrete optimization based on the orthogonal arrays is conducted to obtain the optimal FVST for maximizing SEA under the constraint of the initial peak crushing force (IPCF). The optimized FVSTs are of superior Crashworthiness and great potential as an energy absorber.
-
Crashworthiness design of vehicle structure with tailor rolled blank
Structural and Multidisciplinary Optimization, 2016Co-Authors: Libin Duan, Tao Chen, Aiguo Cheng, Guangyao LiAbstract:Lightweight and Crashworthiness design have been two main challenges in the vehicle industry. These two performances often conflict with each other. To not sacrifice vehicle Crashworthiness performance when performing vehicle lightweight design, a novel inner part of front longitudinal beam (FLB-inner) structure with a tailor rolled blank (TRB) concept is proposed in this work, and the corresponding design method is also proposed to minimize the weight of FLB-inner. Firstly, a full-scale vehicle finite element model is adopted and experimentally verified. Secondly, the conventional uniform thickness FLB-inner panel is replaced with a TRB structure, herein, the FLB-inner is divided into four segments with different thickness according to the Crashworthiness requirements of frontal impact. Then the material constitutive model and finite element modeling for TRB is established. Thirdly, the optimal Latin hypercube sampling (OLHS) technique is used to generate sampling points and the objective and constraints function values are calculated using commercial software LS-DYNA. Based on the simulation results, the ?-SVR surrogate models are constructed. Finally, the artificial bee colony (ABC) algorithm is applied to obtain the optimal thickness distribution of FLB-inner. The results indicated that the weight of the FLB-inner is reduced by 15.21 %, while the Crashworthiness is mproved in comparison with the baseline design.
-
on design of multi cell thin wall structures for Crashworthiness
International Journal of Impact Engineering, 2016Co-Authors: Suzhen Wu, Guangyao Li, Gang Zheng, Qing LiAbstract:Abstract Multi-cell thin-wall structures have drawn increasing attention and been widely applied in automotive and aerospace industries for their significant advantages in high energy absorption and lightweight. The number of cells and the topological configurations of the multi-cell thin-wall structures have a significant effect on the Crashworthiness. In order to investigate the effect of the number of cells and the topological configurations of multi-cell structures on their Crashworthiness characteristics, this paper first sets up the simulation models of multi-cell tubes and verifies their accuracy with the quasi-static and dynamic impact experiments. Second, it compares the energy absorption characteristics of the multi-cell structures with different numbers of cells and topological configurations under dynamic impact condition using finite element analysis (FEA). The results show that the mean crushing force (MFC) and specific energy absorption (SEA) increase with the increase in the number of cells of the multi-cell tubes, among which the five-cell tube has the best energy absorption characteristics. Third, a parametric study is carried out to investigate the effects of wall thickness and topology configurations on the Crashworthiness of five-cell tubes. Finally, the multiobjective Non-dominated Sorting Genetic Algorithm (NSGA-II) is used to further optimize the five-cell tube for maximizing specific energy absorption and minimizing peak crushing force (PCF). The optimal five-cell tube has excellent Crashworthiness and is a potential energy absorber.
-
optimization of foam filled bitubal structures for Crashworthiness criteria
Materials & Design, 2012Co-Authors: Yong Zhang, Guangyao Li, Qing LiAbstract:Thin-walled structures have been widely used as key components in automobile and aerospace industry to improve the Crashworthiness and safety of vehicles while maintaining overall light-weight. This paper aims to explore the design issue of thin-walled bitubal column structures filled with aluminum foam. As a relatively new filler material, aluminum foam can increase Crashworthiness without sacrificing too much weight. To optimize Crashworthiness of the foam-filled bitubal square column, the Kriging meta-modeling technique is adopted herein to formulate the objective and constraint functions. The genetic algorithm (GA) and Non-dominated Sorting Genetic Algorithm II (NSGA II) are used to seek the optimal solutions to the single and multiobjective optimization problems, respectively. To compare with other thin-walled configurations, the design optimization is also conducted for empty bitubal column and foam-filled monotubal column. The results demonstrate that the foam-filled bitubal configuration has more room to enhance the Crashworthiness and can be an efficient energy absorber. Language: en
-
Crashworthiness design for functionally graded foam filled thin walled structures
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Guangyao Li, Shiwei Zhou, Wei Li, Qing LiAbstract:Foam-filled thin-wall structures have exhibited significant advantages in light weight and high energy absorption and been widely applied in automotive, aerospace, transportation and defence industries. Unlike existing uniform foam materials, this paper introduces functionally graded foam (FGF) fillers to fill thin-walled structures, aiming to improve Crashworthiness. In this novel structure, the foam density varies throughout the depth in a certain gradient. Numerical simulations showed that gradient exponential parameter m that controls the variation of foam density has significant effect on system Crashworthiness. In this study, the single and multiobjective particle swarm optimization methods are used to seek for optimal gradient, where response surface models are established to formulate specific energy absorption and peak crushing force. The results yielded from the optimizations indicate that the FGF material is superior to its uniform counterparts in overall Crashworthiness. The data has considerable implication in design of FGF materials for optimizing structural Crashworthiness.
Hongbing Fang - One of the best experts on this subject based on the ideXlab platform.
-
multiobjective Crashworthiness optimization design of functionally graded foam filled tapered tube based on dynamic ensemble metamodel
Materials & Design, 2014Co-Authors: Hongbing Fang, Qixiang Qing, Xiangzheng Kong, Jiuru XiaoAbstract:Foam-filled thin-walled structures have recently gained attention with increasing interest due to their excellent energy absorption capacity. In this study, a new type of foam-filled thin-walled structure called as functionally graded foam-filled tapered tube (FGFTT) is proposed. FGFTT consists of graded density foam and thin-walled tapered tube. In order to investigate the energy absorption characteristics of FGFTTs, the numerical simulations for two kinds of FGFTTs subjected to axial dynamical loading are carried out by nonlinear finite element code LS-DYNA. In addition, a new kind of multiobjective Crashworthiness optimization method employing the dynamic ensemble metamodeling method together with the multiobjective particle swarm optimization (MOPSO) algorithm is presented. This new kind of multiobjective Crashworthiness optimization method is then used to implement the Crashworthiness optimization design of FGFTTs. Meanwhile, the Crashworthiness optimization designs of FGFTTs are implemented by using traditional multiobjective Crashworthiness optimization method, which employs metamodels such as polynomial response surface (PRS), radial basis function (RBF), kriging (KRG), support vector regression (SVR) or the ensemble with the static design of experiment (DOE). Finally, by comparing the optimal designs of FGFTTs obtained by using the new multiobjective Crashworthiness optimization method and the traditional one, the results show that the proposed new Crashworthiness optimization method is more feasible.
-
optimal Crashworthiness design of a spot welded thin walled hat section
Finite Elements in Analysis and Design, 2006Co-Authors: Yujiang Xiang, Qian Wang, Hongbing FangAbstract:In automotive industry, Crashworthiness design is of special interest to ensure passengers safety and reduce vehicle costs. Thin-walled beams are the main energy absorbing structures in frontal and real collisions; therefore, it is important to investigate their energy-absorption and optimize their performance. For Crashworthiness designs of thin-walled sections, much attention has been given to the size and shape designs of the cross-section, while limited study has been performed to incorporate spot-weld modelling and their numbers as design parameters in Crashworthiness optimization. The spacing of spot-welds has a strong effect on Crashworthiness performance, because it can change a single complete folding length. This study focuses on the optimal Crashworthiness design of a spot-welded thin-walled hat section subject to an axial crushing force. Based on comparisons to experimental data, an appropriate spot-weld model is selected and used in numerical simulations. The mass of the beam is optimized subjected to constraints of required mean crushing force and bending stiffness. A "Two-step RSM-Enumeration" algorithm is employed to efficiently solve this optimization problem of mixed-type variables.
Wei Li - One of the best experts on this subject based on the ideXlab platform.
-
Crashworthiness design for functionally graded foam filled thin walled structures
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Guangyao Li, Shiwei Zhou, Wei Li, Qing LiAbstract:Foam-filled thin-wall structures have exhibited significant advantages in light weight and high energy absorption and been widely applied in automotive, aerospace, transportation and defence industries. Unlike existing uniform foam materials, this paper introduces functionally graded foam (FGF) fillers to fill thin-walled structures, aiming to improve Crashworthiness. In this novel structure, the foam density varies throughout the depth in a certain gradient. Numerical simulations showed that gradient exponential parameter m that controls the variation of foam density has significant effect on system Crashworthiness. In this study, the single and multiobjective particle swarm optimization methods are used to seek for optimal gradient, where response surface models are established to formulate specific energy absorption and peak crushing force. The results yielded from the optimizations indicate that the FGF material is superior to its uniform counterparts in overall Crashworthiness. The data has considerable implication in design of FGF materials for optimizing structural Crashworthiness.
-
design optimization of regular hexagonal thin walled columns with Crashworthiness criteria
Finite Elements in Analysis and Design, 2007Co-Authors: Qing Li, Shuyao Long, Xujing Yang, Wei LiAbstract:New functional requirements stimulate a rapid development of novel structural members. This paper presents a Crashworthiness design of the regular hexagonal thin-walled columns for different sectional profiles. To formulate the complex Crashworthiness design problem, the surrogate model method, more specifically, the response surface method (RSM), is utilized. The design of experiments (DoE) of the factorial design and D-optimal criterion techniques is employed to construct the response surface (RS) for the objective of specific energy absorption (SEA) and the constraint of maximum peak load (Max PL), respectively. In this study, the singly celled and multiply celled hexagonal columns are taken into account with the different sectional configurations. A comparison is made between these different hexagonal profiles, and the Crashworthiness merits of multiply connected (MC) sections of the singly celled configuration and the side-connected section of triply celled configuration are quantified.
Ping Hu - One of the best experts on this subject based on the ideXlab platform.
-
Comparative study on thin-walled structures with function graded strength and tapered angle
International Journal of Crashworthiness, 2018Co-Authors: Liang Ying, Haolin Ma, Shuai Chen, Ping HuAbstract:This paper compares the Crashworthiness characteristics of straight functionally graded strength (SFGS), tapered uniform strength (TUS) and classical straight uniform strength (SUS) tubes under axial crushing loading. Based on the numerical simulation, multi-optimisations are performed to optimise the Crashworthiness of the SFGS, TUS and SUS tubes. Result of comparative study shows that the SFGS tubes are similar to the TUS tubes to some extent, since both of them have obviously larger CFE value, relatively good comprehensive Crashworthiness and more predominant Pareto fronts than the traditional SUS tubes. Nevertheless, obvious differences between SFGS and TUS tubes exist. The relative differences of SEA and PCF for all the SFGS tubes are positive while that of the TUS tubes are negative. Finally, the comparison on Pareto fronts suggests that if the allowable tapered angle is big enough, it is better to employ the TUS tubes with relatively big tapered angle.
-
Magic Cube approach application on Crashworthiness design of front rail in front angle impact
2009 International Conference on Mechatronics and Automation, 2009Co-Authors: Sibo Hu, Chang Qi, Ping HuAbstract:This paper is concerned with Crashworthiness design of a front rail on a vehicle chassis frame structure considering crash direction uncertainty. Front rail as a main energy absorption component in front impact, may perform low energy-absorption deformation in front angle impact, such as global bending collapse. Magic Cube approach (MQ), a systematic design approach, is conducted to analyze the design problem: by applying time and space decomposition, a subsystem-to-component model is developed, which simplified the design domains; by using topology optimization method, a new front rail is designed under inclined loading, which saves 29% material. Numerical simulation is carried out with LS-DYNA in order to compare the Crashworthiness of two designs (new front rail and rectangle cross-section front rail). The result shows that new front rail has better adaptability of uncertain loading directions than original rectangle cross-section front rail and Crashworthiness design process should consider the oblique loading direction.