Dr Jianguang Fang has joined UTS in 2017. Dr Fang received a PhD from The University of Sydney in 2016. He has published over 50 articles in prestigious international journals. 6 of his publications are listed as ESI Highly Cited Papers in Web of Science. He has >1400 citation and an H-index of 22 in Google Scholar.
Dr Fang was awarded a Chancellor’s Postdoctoral Research Fellowship from UTS and a Discovery Project from Australian Research Council.
- International Association for Computational Mechanics (IACM)
- Australian Association for Computational Mechanics (AACM)
- International Society for Structural and Multidisciplinary optimisation (ISSMO)
- International Association of Protective Structures
- International Society of Impact Engineering
- Engineering Structures
- Structural and Multidisciplinary Optimization
- International Journal of Mechanical Sciences
- Thin-walled Structures
- Materials & Design
- Composites: Part B
- Engineering Optimization
- Steel and Composite Structures
- International Journal of Protective Structures
- Reliability Engineering & System Safety
- Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
- Advances in Engineering Software
- Construction & Building Materials
- Simulation Modelling Practice and Theory
- European Journal of Mechanics / A Solids
- Journal of Mechanical Design –Transactions of the ASME
- Mathematical Problems in Engineering
- Composite Structures
- Acta Biomaterialia
- IEEE Access
- Journal of Manufacturing Processes
- Mechanics of Materials
- Mechanics of Advanced Materials and Structures
- Journal of Central South University
- Journal of Mechanical Science and Technology
- Applied Mathematical Modelling
Can supervise: YES
- Constitutive modelling of concrete
- Phase field modelling of brittle and ductile fracture
- Computational plasticity
- Metamodel based optimisation
- Topology optimisation
- Energy absorption of novel materials and structures
- Crashworthiness optimisation
- Impact mechanics
- Engineering Mechanics
- Mechanics of Solids
Fang, J, Wu, C, Li, J, Liu, Q, Wu, C, Sun, G & Li, Q 2019, 'Phase field fracture in elasto-plastic solids: Variational formulation for multi-surface plasticity and effects of plastic yield surfaces and hardening', International Journal of Mechanical Sciences, vol. 156, pp. 382-396.View/Download from: Publisher's site
The phase field modelling has been extended from brittle fracture to ductile fracture by incorporating plasticity. However, the effects of plastic yield functions and hardening on the fracture behaviour have not been examined systematically to date. The phase field fracture coupled with multi-surface plasticity is formulated in the variational framework for the unified yield criterion, which is able to facilitate the study on different yield surfaces. First, the homogeneous solutions of fracture in elasto-plastic solids are derived analytically for 1D and 2D cases. The results show that a greater hardening modulus would lead to an ascending branch of the stress versus strain curve; and the yield function may significantly affect the stress state and phase field damage. Second, the finite element (FE) technique is implemented for modelling the phase field fracture in elasto-plastic solids, in which the stress update and consistent tangent modular matrix are derived for the unified yield criterion. Finally, three numerical examples are presented to explore the effects of the yield function and material hardening. It is found that the yield function and material hardening could significantly affect the crack propagation and the final fracture pattern. In particular, the Tresca yield function tends to create a straight crack path orthogonal to the first principal stress, while the other yield functions show no sizeable difference in their crack paths.
Fang, J, Wu, C, Liu, Q, Sun, G & Li, Q 2019, 'Implicit Integration of the Unified Yield Criterion in the Principal Stress Space', JOURNAL OF ENGINEERING MECHANICS, vol. 145, no. 7.View/Download from: Publisher's site
Fang, J, Wu, C, Rabczuk, T, Wu, C, Ma, C, Sun, G & Li, Q 2019, 'Phase field fracture in elasto-plastic solids: Abaqus implementation and case studies', Theoretical and Applied Fracture Mechanics, vol. 103.View/Download from: Publisher's site
© 2019 Elsevier Ltd Phase field modelling for fracture has been extended from elastic solids to elasto-plastic solids. In this study, we present the implementation procedures of a staggered scheme for phase field fracture of elasto-plastic solids in commercial finite element software Abaqus using subroutines UEL and UMAT. The UMAT is written for the constitutive behaviour of elasto-plastic solids, while the UEL is written for the phase field fracture. The phase field and displacement field are solved separately using the Newton-Raphson iteration method. In each iteration, one field is computed by freezing the other field at the last loading increment. A number of benchmark examples are tested from one single element up to 3D problems. The correctness of the staggered scheme is verified analytically in terms of the stress-strain curve and the evolution of the phase field in the one single element example. In the 2D and 3D problems, the fracture behaviour of elasto-plastic solids can be reproduced in terms of reaction force curve and crack propagation, which exhibit good agreement with the experimental observations and numerical results in literature. Not only can the proposed implementation help attract more academic researchers, but also engineering practitioners to take the advantages of phase field modelling for fracture in elasto-plastic solids. The Abaqus subroutine codes can be downloaded online from Mendeley data repository linked to this work (The link is provided in Supplementary material).
Liu, J, Wu, C, Li, J, Fang, J, Su, Y & Shao, R 2019, 'Ceramic balls protected ultra-high performance concrete structure against projectile impact-A numerical study', INTERNATIONAL JOURNAL OF IMPACT ENGINEERING, vol. 125, pp. 143-162.View/Download from: UTS OPUS or Publisher's site
Fu, J, Liu, Q, Liufu, K, Deng, Y, Fang, J & Li, Q 2019, 'Design of bionic-bamboo thin-walled structures for energy absorption', THIN-WALLED STRUCTURES, vol. 135, pp. 400-413.View/Download from: UTS OPUS or Publisher's site
Liu, T, Sun, G, Fang, J, Zhang, J & Li, Q 2019, 'Topographical design of stiffener layout for plates against blast loading using a modified ant colony optimization algorithm', STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION, vol. 59, no. 2, pp. 335-350.View/Download from: Publisher's site
Ma, C, Li, Q, Zheng, P, Zhou, S, Gao, H, Fang, J & Wang, Y 2019, 'Effects of static eccentricity on the no-load back electromotive force of external rotor permanent magnet brushless DC motor used as in-wheel motor', IET ELECTRIC POWER APPLICATIONS, vol. 13, no. 5, pp. 604-613.View/Download from: UTS OPUS or Publisher's site
Pang, T, Zheng, G, Fang, J, Ruan, D & Sun, G 2019, 'Energy absorption mechanism of axially-varying thickness (AVT) multicell thin-walled structures under out-of-plane loading', Engineering Structures, vol. 196.View/Download from: Publisher's site
© 2019 Elsevier Ltd Multicell columns have becoming increasingly attractive in crashworthiness applications due to their high efficiency of material utilization. Meanwhile, an urgent need exists to develop new structures to achieve the aim of light weight without sacrificing crashworthiness. A novel multicell column with axially-varying thickness (AVT) is proposed in this study. Quasi-static crushing tests were firstly performed experimentally to investigate crushing behaviors. Subsequently, corresponding numerical simulation models were built, validated, and used to conduct a parametric study. Finally, analytical equations for the mean crushing force for AVT multicell columns were derived and used to assess the crashworthiness of multicell columns according to SFE (super folding element) method. The numerical results agreed well with experimental results in terms of deformation mode and crushing forces, and the theoretical predictions were validated by the experimental results. It was concluded that the thickness gradient of AVT multicell columns could effectively reduce the initial peak crushing force while maintaining energy absorption capacity over a long crushing distance. From this perspective, the AVT multicell columns demonstrated competitive advantages over uniform columns as energy absorbers. Moreover, the analytical prediction could be a powerful tool for designing crashworthy structures.
Sun, G, Zhang, J, Li, S, Fang, J, Wang, E & Li, Q 2019, 'Dynamic response of sandwich panel with hierarchical honeycomb cores subject to blast loading', Thin-Walled Structures, vol. 142, pp. 499-515.View/Download from: Publisher's site
© 2019 Elsevier Ltd This paper introduces a novel hierarchical core structure to sandwich panel for bearing the blast loading, in which each vertex of a regular hexagonal cell was replaced with a smaller hexagonal unit. The finite element (FE) models of such hierarchical honeycomb sandwich panels were established and validated with the experiments under different impulse loads. The hierarchical honeycomb cores were compared with the regular honeycomb counterpart in terms of the peak deflection on the back facesheet, compression and specific energy absorption (SEA) of the core. The results showed that the maximum deflection at the back facesheet of the hierarchical honeycomb sandwich panels were smaller than the regular honeycomb counterpart for a higher level of blast load (specifically, the dimensionless impulse higher than 0.06). It was found that the structural hierarchical parameter γ (i.e. the ratio of the newly-introduced smaller hexagonal edge length (L1) to the regular hexagon edge length (L0)), had limited influence on the maximum deflection of back facesheet of the sandwich panel, but had a significant effect on the SEA of the cores.
Wu, C, Fang, J & Li, Q 2019, 'Multi-material topology optimization for thermal buckling criteria', Computer Methods in Applied Mechanics and Engineering, vol. 346, pp. 1136-1155.View/Download from: UTS OPUS or Publisher's site
© 2018 Elsevier B.V. The structures in thermal environment often suffer from severe thermal expansion, potentially leading to buckling failure. This study aims to address this issue by proposing multi-material topology optimization for thermomechanical buckling problems. The density-based model with the rational approximation of material properties (RAMP) is adopted here for parameterization of multiple materials. The sensitivities of thermomechanical compliance and buckling are derived through the adjoint technique. The globally convergent version of the method of moving asymptotes (GCMMA) is employed to solve the non-monotonic topology optimization problem. In this study, two numerical examples are presented to illustrate the effectiveness of the proposed method, in which the total volume of multi-materials is minimized subject to thermoelastic compliance and buckling constraints. The examples exhibit significant difference in the final topologies for mechanical buckling and thermomechanical buckling optimization. The study demonstrates the importance of thermomechanical buckling criteria for the design of structures operating in a temperature-varying environment.
Wu, C, Gao, Y, Fang, J, Lund, E & Li, Q 2019, 'Simultaneous Discrete Topology Optimization of Ply Orientation and Thickness for Carbon Fiber Reinforced Plastic-Laminated Structures', JOURNAL OF MECHANICAL DESIGN, vol. 141, no. 4.View/Download from: Publisher's site
Xu, Y, Gao, Y, Wu, C, Fang, J & Li, Q 2019, 'Robust topology optimization for multiple fiber-reinforced plastic (FRP) composites under loading uncertainties', STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION, vol. 59, no. 3, pp. 695-711.View/Download from: Publisher's site
Zhang, Y, Liu, Q, He, Z, Zong, Z & Fang, J 2019, 'Dynamic impact response of aluminum honeycombs filled with Expanded Polypropylene foam', COMPOSITES PART B-ENGINEERING, vol. 156, pp. 17-27.View/Download from: UTS OPUS or Publisher's site
Zheng, K, Liao, Z, Yoda, N, Fang, J, Chen, J, Zhang, Z, Zhong, J, Peck, C, Sasaki, K, Swain, MV & Li, Q 2019, 'Investigation on masticatory muscular functionality following oral reconstruction – An inverse identification approach', Journal of Biomechanics, vol. 90, pp. 1-8.View/Download from: UTS OPUS or Publisher's site
© 2019 Elsevier Ltd The human masticatory system has received significant attention in the areas of biomechanics due to its sophisticated co-activation of a group of masticatory muscles which contribute to the fundamental oral functions. However, determination of each muscular force remains fairly challenging in vivo; the conventional data available may be inapplicable to patients who experience major oral interventions such as maxillofacial reconstruction, in which the resultant unsymmetrical anatomical structure invokes a more complex stomatognathic functioning system. Therefore, this study aimed to (1)establish an inverse identification procedure by incorporating the sequential Kriging optimization (SKO)algorithm, coupled with the patient-specific finite element analysis (FEA)in silico and occlusal force measurements at different time points over a course of rehabilitation in vivo; and (2)evaluate muscular functionality for a patient with mandibular reconstruction using a fibula free flap (FFF)procedure. The results from this study proved the hypothesis that the proposed method is of certain statistical advantage of utilizing occlusal force measurements, compared to the traditionally adopted optimality criteria approaches that are basically driven by minimizing the energy consumption of muscle systems engaged. Therefore, it is speculated that mastication may not be optimally controlled, in particular for maxillofacially reconstructed patients. For the abnormal muscular system in the patient with orofacial reconstruction, the study shows that in general, the magnitude of muscle forces fluctuates over the 28-month rehabilitation period regardless of the decreasing trend of the maximum muscular capacity. Such finding implies that the reduction of the masticatory muscle activities on the resection side might lead to non-physiological oral biomechanical responses, which can change the muscular activities for stabilizing the reconstructed mandible.
Chen, S, Yu, H & Fang, J 2018, 'A novel multi-cell tubal structure with circular corners for crashworthiness', Thin-Walled Structures, vol. 122, pp. 329-343.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier Ltd Multi-cell structures have proven to own excellent energy absorbing capability and lightweight effect in the automotive and aerospace industries. The cross-sectional configuration of the multi-cell structure has a significant effect on crashworthiness. Unlike existing multi-cell tubes, a new type of five-cell profile with four circular elements at the corners (C5C) was proposed in this study. To investigate the crashworthiness of the new C5C tube, finite element (FE) models were first established by using the nonlinear finite element code LS-DYNA and validated with experimental results. Following that, the comparison of the C5C tube and other multi-cell tubes with the same mass was conducted to quantify the relative merits of the C5C tube. Then, a detailed study was performed to analyze the effect of the corner-cell size and wall thickness. Finally, the optimization design was carried out to seek the optimal structure. The results showed that the new multi-cell structure can absorb much more crash energy than other four types of tubes. Moreover, the energy absorption of this new multi-cell tube C5C was affected by the corner-cell size and wall thickness significantly. A proper corner-cell size and slightly thicker internal ribs were recommended. In addition, the multi-objective particle swarm optimization (MOPSO) algorithm and radial basis function (RBF) surrogate model can optimize the structure effectively. The outcomes of the present study will facilitate the design of multi-cell structures with better crashworthiness.
Fang, J, Sun, G, Qiu, N, Pang, T, Li, S & Li, Q 2018, 'On hierarchical honeycombs under out-of-plane crushing', International Journal of Solids and Structures, vol. 135, pp. 1-13.View/Download from: UTS OPUS or Publisher's site
© 2017 Hierarchy has been introduced to honeycomb structures in pursuing ultralight materials with outstanding mechanical properties. Nevertheless, the hierarchical honeycombs under the out-of-plane loads have not been well studied experimentally and analytically for energy absorption to date. This study aimed to apply a special structural hierarchy to the honeycomb by replacing the sides of hexagons with smaller hexagons. The quasi-static test of the hierarchical honeycomb specimen was first conducted experimentally to investigate the crushing behaviours; and then the corresponding finite element (FE) analyses were performed. Finally, the analytical solutions to the mean crushing force and plateau stress were derived based on the simplified super folding element (SSFE) method. It was shown that the experimental data and numerical results agreed well in terms of crushing force versus displacement relation and energy absorption characteristics; and the analytical results were validated by the experimental test. Importantly, the hierarchy could improve the energy absorption; and the increase in the order and number of replacement hexagons could excavate the advantage even further. Specifically, the second order honeycomb characterized by five smaller replacement hexagons at each order can yield a plateau stress 2.63 and 4.16 times higher than the regular honeycomb and the aluminium foam, respectively. While it might lead to global bending, structural hierarchy provides new architectural configurations for developing novel ultralight materials with exceptional energy absorption capacity under out-of-plane loads.
Liu, Q, Shen, H, Wu, Y, Xia, Z, Fang, J & Li, Q 2018, 'Crash responses under multiple impacts and residual properties of CFRP and aluminum tubes', COMPOSITE STRUCTURES, vol. 194, pp. 87-103.View/Download from: UTS OPUS or Publisher's site
Ma, C, Chen, C, Li, Q, Gao, H, Kang, Q, Fang, J, Cui, H, Teng, K & Lv, X 2018, 'Analytical Calculation of No-Load Magnetic Field of External Rotor Permanent Magnet Brushless Direct Current Motor Used as In-Wheel Motor of Electric Vehicle', IEEE Transactions on Magnetics, vol. 54, no. 4.View/Download from: UTS OPUS or Publisher's site
© 1965-2012 IEEE. An analytical method for calculating the no-load magnetic field of external rotor permanent magnet brushless direct current motor (PMBLDCM) used as in-wheel motor of electric vehicle in the stator static coordinate and the rotor motion coordinate is presented in this paper. First, the analytic formulas of slotless permanent magnetic field in both coordinate systems are derived, respectively. Then, the complex relative permeance of external rotor PMBLDCM in both coordinate systems is calculated. Finally, the analytical solution of the no-load magnetic field in both coordinate systems is derived by applying the magnetic potential multiplied by the complex relative permeance. In this paper, a 46-pole-51-slot external rotor PMBLDCM is taken as an example, and the accuracy of the proposed analytical model is verified by the finite-element results. Based on the analytical model, the influences of the stator slotting effect on the no-load magnetic field of the external rotor and the inner stator are analyzed. The spatial order characteristics and frequency characteristics of the no-load magnetic field of the external rotor PMBLDCM in both coordinate systems are revealed, respectively.
Qiu, N, Gao, Y, Fang, J, Sun, G & Kim, NH 2018, 'Topological design of multi-cell hexagonal tubes under axial and lateral loading cases using a modified particle swarm algorithm', Applied Mathematical Modelling, vol. 53, pp. 567-583.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier Inc. Multi-cell structures have widely been studied due to their excellent energy absorption ability. However, few systematic studies have been conducted on the topological design of cross-sectional configurations of thin-walled tubes. To make full use of the material, topology optimization of multi-cell hexagonal tubes was conducted under both axial compression and lateral bending loadings. A binary particle swarm optimization (PSO) was enhanced by introducing the mass constraint factor to guide the movement of particles, which could improve the success rate of obtaining the global optimum. It was found that the optimum designs under the axial load placed the material outward to strengthen the interaction between the outer and inner walls and created more partitions between the inside rib walls. While under the lateral load, all the optimum designs have diagonally-connected elements to resist local deformation, and the material was also placed outward to increase the moment of inertia and thus to resist the global deformation. For the multiple loading cases, the final optimal designs are similar to the compression designs or combined designs from the two loading cases.
Qiu, N, Gao, Y, Fang, J, Sun, G, Li, Q & Kim, NH 2018, 'Crashworthiness optimization with uncertainty from surrogate model and numerical error', THIN-WALLED STRUCTURES, vol. 129, pp. 457-472.View/Download from: UTS OPUS or Publisher's site
Qiu, N, Park, C, Gao, Y, Fang, J, Sun, G & Kim, NH 2018, 'Sensitivity-Based Parameter Calibration and Model Validation under Model Error', Journal of Mechanical Design, vol. 140, no. 1, pp. 1-9.View/Download from: UTS OPUS or Publisher's site
© 2018 by ASME. In calibrating model parameters, it is important to include the model discrepancy term in order to capture missing physics in simulation, which can result from numerical, measurement, and modeling errors. Ignoring the discrepancy may lead to biased calibration parameters and predictions, even with an increasing number of observations. In this paper, a simple yet efficient calibration method is proposed based on sensitivity information when the simulation model has a model error and/or numerical error but only a small number of observations are available. The sensitivity-based calibration method captures the trend of observation data by matching the slope of simulation predictions and observations at different designs and then utilizing a constant value to compensate for the model discrepancy. The sensitivity-based calibration is compared with the conventional least squares calibration method and Bayesian calibration method in terms of parameter estimation and model prediction accuracies. A cantilever beam example, as well as a honeycomb tube crush example, is used to illustrate the calibration process of these three methods. It turned out that the sensitivity-based method has a similar performance with the Bayesian calibration method and performs much better than the conventional method in parameter estimation and prediction accuracy.
Sun, G, Liu, T, Fang, J, Steven, GP & Li, Q 2018, 'Configurational optimization of multi-cell topologies for multiple oblique loads', Structural and Multidisciplinary Optimization, vol. 57, no. 2, pp. 469-488.View/Download from: UTS OPUS or Publisher's site
© 2017, Springer-Verlag GmbH Germany. Multi-cell thin-walled structures exhibit significant advantages in maximizing energy absorption and minimizing mass during vehicle crashes. Since the topological distribution of wall members has an appreciable effect on the crashworthiness, their design signifies an important area of research. As a major energy absorber, multi-cell tubes are more commonly encounter oblique loading in real life. Thus, this study aimed to optimize multi-cell cross-sectional configuration of tubal structures for multiple oblique loading cases. An integer coded genetic algorithm (ICGA) is introduced here to optimize topological distribution of multi-celled web members for single/multiple oblique impacting conditions. Specifically, material distribution in a form of allocating web wall thickness, starting from zero, is considered as design variables and maximization of energy absorption (EA) as the design objective under the predefined peak crushing force and structural mass constraints. The optimization allows generating uniform or non-uniform thickness distribution in different web wall configurations to maximize usage efficiency of material. Compared with the baseline structure, the optimized configurations largely improved the energy absorption in both single and multiple load cases. The examples demonstrate that the proposed ICGA-based design method not only provides a useful approach to searching for novel crashworthy structures in a systematic fashion, but also develops a series of novel multi-cell topologies for multiple oblique loading cases.
Sun, G, Zhang, H, Fang, J, Li, G & Li, Q 2018, 'A new multi-objective discrete robust optimization algorithm for engineering design', Applied Mathematical Modelling, vol. 53, pp. 602-621.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier Inc. This paper proposes a novel multi-objective discrete robust optimization (MODRO) algorithm for design of engineering structures involving uncertainties. In the present MODRO procedure, grey relational analysis (GRA), coupled with principal component analysis (PCA), was used as a multicriteria decision making model for converting multiple conflicting objectives into one unified cost function. The optimization process was iterated using the successive Taguchi approach to avoid the limitation that the conventional Taguchi method fails to deal with a large number of design variables and design levels. The proposed method was first verified by a mathematical benchmark example and a ten-bar truss design problem; and then it was applied to a more sophisticated design case of full scale vehicle structure for crashworthiness criteria. The results showed that the algorithm is able to achieve an optimal design in a fairly efficient manner attributable to its integration with the multicriteria decision making model. Note that the optimal design can be directly used in practical applications without further design selection. In addition, it was found that the optimum is close to the corresponding Pareto frontier generated from the other approaches, such as the non-dominated sorting genetic algorithm II (NSGA-II), but can be more robust as a result of introduction of the Taguchi method. Due to its independence on metamodeling techniques, the proposed algorithm could be fairly promising for engineering design problems of high dimensionality.
Wu, Y, Fang, J, He, Y & Li, W 2018, 'Crashworthiness of hierarchical circular-joint quadrangular honeycombs', THIN-WALLED STRUCTURES, vol. 133, pp. 180-191.View/Download from: UTS OPUS or Publisher's site
Wu, Y, Li, W, Fang, J & Lan, Q 2018, 'Multi-objective robust design optimization of fatigue life for a welded box girder', Engineering Optimization, vol. 50, no. 8, pp. 1252-1269.View/Download from: UTS OPUS or Publisher's site
© 2017 Informa UK Limited, trading as Taylor & Francis Group To reduce the scatter of fatigue life for welded structures, a robust optimization method is presented in this study based on a dual surrogate modelling and multi-objective particle swam optimization algorithm. Considering the perturbations of material parameters and environment variables, the mean and standard deviation of fatigue life are fitted using dual surrogate modelling and selected as the objective function to be minimized. As an example, a welded box girder is presented to reduce the standard deviation of fatigue life. A set of non-dominated solutions is produced through a multi-objective particle swam optimization algorithm. A cognitive approach is used to select the optimum solution from the Pareto sets. As a comparative study, traditional single objective optimizations are also presented in this study. The results reduced the standard deviation of the fatigue life by about 16.5%, which indicated that the procedure improved the robustness of the fatigue life.
Fang, J, Qiu, N, An, X, Xiong, F, Sun, G & Li, Q 2017, 'Crashworthiness design of a steel-aluminum hybrid rail using multi-response objective-oriented sequential optimization', ADVANCES IN ENGINEERING SOFTWARE, vol. 112, pp. 192-199.View/Download from: UTS OPUS or Publisher's site
Fang, J, Sun, G, Qiu, N, Kim, NH & Li, Q 2017, 'On design optimization for structural crashworthiness and its state of the art', Structural and Multidisciplinary Optimization, vol. 55, no. 3, pp. 1091-1119.View/Download from: UTS OPUS or Publisher's site
© 2016 Springer-Verlag Berlin HeidelbergOptimization 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.
Fang, J, Sun, G, Qiu, N, Steven, GP & Li, Q 2017, 'Topology Optimization of Multicell Tubes Under Out-of-Plane Crushing Using a Modified Artificial Bee Colony Algorithm', Journal of Mechanical Design, Transactions of the ASME, vol. 139, no. 7.View/Download from: UTS OPUS or Publisher's site
Copyright © 2017 by ASME. Multicell tubal structures have generated increasing interest in engineering design for their excellent energy-absorbing characteristics when crushed through severe plastic deformation. To make more efficient use of the material, topology optimization was introduced to desi gn multicell tubes under normal crushing. The design problem was formulated to maximize the energy absorption while constraining the structural mass. In this research, the presence or absence of inner walls were taken as design variables. To deal with such a highly nonlinear problem, a heuristic design methodology was proposed based on a modified artificial bee colony (ABC) algorithm, in which a constraint-driven mechanism was introduced to determine adjacent food sources for scout bees and neighborhood sources for employed and onlooker bees. The fitness function was customized according to the violation or the satisfaction of the constraints. This modified ABC algorithm was first verified by a square tube with seven design variables and then applied to four other examples with more design variables. The results demonstrated that the proposed heuristic algorithm is capable of handling the topology optimization of multicell tubes under out-of-plane crushing. They also confirmed that the optimized topological designs tend to allocate the material at the corners and around the outer walls. Moreover, the modified ABC algorithm was found to perform better than a genetic algorithm (GA) and traditional ABC in terms of best, worst, and average designs and the probability of obtaining the true optimal topological configuration.
Pang, T, Li, Y, Kang, H, Sun, G, Fang, J & Li, Q 2017, 'On functionally-graded crashworthy shape of conical structures for multiple load cases', Journal of Mechanical Science and Technology, vol. 31, no. 6, pp. 2861-2873.View/Download from: UTS OPUS or Publisher's site
© 2017, The Korean Society of Mechanical Engineers and Springer-Verlag GmbH Germany. Many studies on energy absorbers have been focused on tapered tubes because they have significant advantages in crashworthiness and provide a desired constant load-deflection response. However, few studies have been reported on tapered tubes with nonlinearlyvariable diameters along the longitudinal direction. This paper presents thin-walled Functionally graded tapered tube (FGTT) with a diameter varying nonlinearly subject to axial (0°) and oblique (10°, 20°, 30°) impacts. To explore the advantages of FGTT, conventional Straight/Conical circular tube (SCT/CCT) with the same mass are compared; and FGTTs with a gradient exponent n > 1 are found to be preferable to others in terms of energy absorption capacity under small impact angles. Then, crashworthiness analyses of different crushing distances are conducted and it is found that under a large impact angle (e.g. 20°, 30°), FGTT with a short crushing distance (e.g. 40 mm) have a higher mean crashing force than long crushing distance (e.g. 120 mm), especially for n > 1. In addition, the effect of geometric parameters, such as the gradient exponent n and diameter range ΔD between top (incident) and bottom (distal) diameters of FGTTs, are also studied and it is found that the FGTT with ΔD = 40 mm and n > 1 exhibits better crashworthiness than the others under small impact angles (0°, 10°). This paper demonstrates that such FGTT structures have a certain potential to be an energy absorber.
Sun, G, Pang, T, Fang, J, Li, G & Li, Q 2017, 'Parameterization of criss-cross configurations for multiobjective crashworthiness optimization', International Journal of Mechanical Sciences, vol. 124-125, pp. 145-157.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier Ltd Thin-walled tubes have exhibited extraordinary advantages in lightweight and energy absorption for crashing scenarios. Geometric configuration of such tubal structures is of decisive effects on crashing behaviors. In this study, crashing characteristics of conventional square tube and a criss-cross tube were first conducted using both experimental and numerical analyses, through which the finite element (FE) models were well validated. It was also revealed that the energy absorption of the criss-cross sectional tube was about 150% higher than that of square column with the same weight. Further, a range of criss-cross sections were parametrically modeled with spline curves and a parametric study was subsequently performed to explore the effects of different parameterized shapes on crashing characteristics. It was found that the geometric parameters significantly affected crashworthiness of the criss-cross tubes, and the criss-cross tubes with a spline curve (CCT_SPL) surpass the criss-cross tubes with a straight line (CCT_STR) in crashworthiness with the same weight. Finally, to optimize the crashwo rthiness of parameterized criss-cross tubes, the non-dominated sorting genetic algorithm II (NSGA-II) was adopted to seek optimal criss-cross shapes for improving specific energy absorption (SEA) and reducing the peak crashing force (F max ), simultaneously. The optimization results indicate that the CCT_SPL profiles with reasonable geometric parameters are superior to the CCT_STR counterparts with an increase of 11.1% in specific energy absorption.
Sun, G, Zhang, H, Fang, J, Li, G & Li, Q 2017, 'Multi-objective and multi-case reliability-based design optimization for tailor rolled blank (TRB) structures', Structural and Multidisciplinary Optimization, vol. 55, no. 5, pp. 1899-1916.View/Download from: UTS OPUS or Publisher's site
© 2016 Springer-Verlag Berlin HeidelbergLight weight and crashworthiness signify two main challenges facing in vehicle industry, which often conflict with each other. In order to achieve light weight while improving crashworthiness, tailor rolled blank (TRB) has become one of the most potential lightweight technologies. To maximize the characteristics of TRB structures, structural optimization has been adopted extensively. Conventional optimization studies have mainly focused on a single loading case (SLC). In practice, however, engineering structures are often subjected to multiple loading cases (MLC), implying that the optimal design under a certain condition may no longer be an optimum under other loading cases. Furthermore, traditional deterministic optimization could become less meaningful or even unacceptable when uncertainties of design variables and noises of system parameters are present. To address these issues, a multi-objective and multi-case reliability-based design optimization (MOMCRBDO) was developed in this study to optimize the TRB hat-shaped structure. The radial basis function (RBF) metamodel was adopted to approximate the responses of objectives and constraints, the non-dominated sorting genetic algorithm II (NSGA-II), coupled with Monte Carlo Simulation (MCS), was employed to seek optimal reliability solutions. The optimal results show that the proposed method is not only capable of improving the reliability of Pareto solutions, but also enhancing the robustness under MLC.
Wu, C, Gao, Y, Fang, J, Lund, E & Li, Q 2017, 'Discrete topology optimization of ply orientation for a carbon fiber reinforced plastic (CFRP) laminate vehicle door', MATERIALS & DESIGN, vol. 128, pp. 9-19.View/Download from: UTS OPUS or Publisher's site
Entezari, A, Fang, J, Sue, A, Zhang, Z, Swain, MV & Li, Q 2016, 'Yielding behaviors of polymeric scaffolds with implications to tissue engineering', MATERIALS LETTERS, vol. 184, pp. 108-111.View/Download from: Publisher's site
Fang, J, Gao, Y, An, X, Sun, G, Chen, J & Li, Q 2016, 'Design of transversely-graded foam and wall thickness structures for crashworthiness criteria', COMPOSITES PART B-ENGINEERING, vol. 92, pp. 338-349.View/Download from: Publisher's site
Fang, J, Gao, Y, Sun, G, Xu, C & Li, Q 2016, 'Multiobjective sequential optimization for a vehicle door using hybrid materials tailor-welded structure', PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE, vol. 230, no. 17, pp. 3092-3100.View/Download from: UTS OPUS or Publisher's site
Li, E, Chen, J, Zhang, Z, Fang, J, Liu, GR & Li, Q 2016, 'Smoothed finite element method for analysis of multi-layered systems - Applications in biomaterials', COMPUTERS & STRUCTURES, vol. 168, pp. 16-29.View/Download from: UTS OPUS or Publisher's site
Qiu, N, Gao, Y, Fang, J, Feng, Z, Sun, G & Li, Q 2016, 'Theoretical prediction and optimization of multi-cell hexagonal tubes under axial crashing', THIN-WALLED STRUCTURES, vol. 102, pp. 111-121.View/Download from: UTS OPUS or Publisher's site
Sun, G, Jiang, H, Fang, J, Li, G & Li, Q 2016, 'Crashworthiness of vertex based hierarchical honeycombs in out-of-plane impact', MATERIALS & DESIGN, vol. 110, pp. 705-719.View/Download from: Publisher's site
An, X, Gao, Y, Fang, J, Sun, G & Li, Q 2015, 'Crashworthiness design for foam-filled thin-walled structures with functionally lateral graded thickness sheets', THIN-WALLED STRUCTURES, vol. 91, pp. 63-71.View/Download from: UTS OPUS or Publisher's site
Fang, J, Gao, Y, Sun, G, Qiu, N & Li, Q 2015, 'On design of multi-cell tubes under axial and oblique impact loads', THIN-WALLED STRUCTURES, vol. 95, pp. 115-126.View/Download from: UTS OPUS or Publisher's site
Fang, J, Gao, Y, Sun, G, Xu, C & Li, Q 2015, 'Multiobjective robust design optimization of fatigue life for a truck cab', RELIABILITY ENGINEERING & SYSTEM SAFETY, vol. 135, pp. 1-8.View/Download from: UTS OPUS or Publisher's site
Fang, J, Gao, Y, Sun, G, Zheng, G & Li, Q 2015, 'Dynamic crashing behavior of new extrudable multi-cell tubes with a functionally graded thickness', INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, vol. 103, pp. 63-73.View/Download from: UTS OPUS or Publisher's site
Qiu, N, Gao, Y, Fang, J, Feng, Z, Sun, G & Li, Q 2015, 'Crashworthiness analysis and design of multi-cell hexagonal columns under multiple loading cases', FINITE ELEMENTS IN ANALYSIS AND DESIGN, vol. 104, pp. 89-101.View/Download from: UTS OPUS or Publisher's site
Sun, G, Fang, J, Tian, X, Li, G & Li, Q 2015, 'Discrete robust optimization algorithm based on Taguchi method for structural crashworthiness design', EXPERT SYSTEMS WITH APPLICATIONS, vol. 42, no. 9, pp. 4482-4492.View/Download from: UTS OPUS or Publisher's site
Sun, G, Tian, X, Fang, J, Xu, F, Li, G & Huang, X 2015, 'Dynamical bending analysis and optimization design for functionally graded thickness (FGT) tube', INTERNATIONAL JOURNAL OF IMPACT ENGINEERING, vol. 78, pp. 128-137.View/Download from: UTS OPUS or Publisher's site
Tian, L, Gao, Y, Fang, J & An, X 2015, 'Multi-objective optimisation of hybrid S-shaped rails under oblique impact loading', INTERNATIONAL JOURNAL OF HEAVY VEHICLE SYSTEMS, vol. 22, no. 2, pp. 137-156.View/Download from: UTS OPUS or Publisher's site
Xiao, Z, Fang, J, Sun, G & Li, Q 2015, 'Crashworthiness design for functionally graded foam-filled bumper beam', ADVANCES IN ENGINEERING SOFTWARE, vol. 85, pp. 81-95.View/Download from: UTS OPUS or Publisher's site
Fang, J, Gao, Y, Sun, G, Xu, C, Zhang, Y & Li, Q 2014, 'Optimization of Spot-Welded Joints Combined Artificial Bee Colony Algorithm with Sequential Kriging Optimization', Advances in Mechanical Engineering, vol. 2014, pp. 1-10.View/Download from: UTS OPUS or Publisher's site
© 2014 Jianguang Fang et al. Generally, spot-welded joints are the weakest parts of structures leading to fatigue failure under fluctuating loads. Therefore, it is important to optimize the spot weld to improve the fatigue life. However, a classical optimization of the spot weld often directly couples finite element analysis (FEA) with optimization algorithm, which may fall into a local optimum or be expensive computationally. In this study, a metamodel-based optimization procedure is proposed to find the optimum locations of spot-welded joints for maximum fatigue life. Based on the initial training points, Kriging model is implemented to approximate the objective function regarding the design variables (i.e., locations of spot welds). To further overcome the defect of traditional Kriging model and improve the accuracy of optimum results, the sequential Kriging optimization (SKO) is utilized, where the Kriging model is updated iteratively by adding new training points to the training dataset till the global optimum is obtained. The optimization is run using artificial bee colony (ABC) algorithm and the results show that our proposed method is able to improve the performance of the spot-welded joint. More importantly, more competent optimum can be found and the optimization can be executed more efficiently, compared to the conventional methods.
Fang, J, Gao, Y, Sun, G, Zhang, Y & Li, Q 2014, 'Parametric analysis and multiobjective optimization for functionally graded foam-filled thin-wall tube under lateral impact', COMPUTATIONAL MATERIALS SCIENCE, vol. 90, pp. 265-275.View/Download from: UTS OPUS or Publisher's site
Gao, Y, Xu, Y, Wu, C & Fang, J 2019, 'Topology optimization of metal and carbon fiber reinforced plastic (CFRP) structures under loading uncertainties', SAE Technical Papers.View/Download from: Publisher's site
© 2019 SAE International. All Rights Reserved. Carbon fiber reinforced plastic (CFRP) composite materials have gained particular interests due to their high specific modulus, high strength, lightweight and perfect corrosion resistance. However, in reality, CFRP composite materials cannot be used alone in some critical places such as positions of joints with hinges, locks. Therefore, metal reinforcements are usually necessary in local positions to prevent structure damage. Besides, if uncertainties present, obtained optimal structures may experience in failures as the optimization usually pushes solutions to the boundaries of constraints and has no room for tolerance and uncertainties, so robust optimization should be considered to accommodate the uncertainties in practice. This paper proposes a mixed topology method to optimize metal and carbon fiber reinforced plastic composite materials simultaneously under nondeterministic load with random magnitude and direction. A joint cost function is employed to contain both the mean and standard deviations of compliance in the robust optimization. The sensitivities of the cost function are derived with respect to the design variables in a nondeterministic context. The discrete material and thickness optimization (DMTO) technique is applied to undertake robust topology optimization for CFRP composites and metal material while the casting constraint to prevent intermediate void was introduced. In this study, two examples are presented to demonstrate the effectiveness of the proposed methods. The robust topology optimization results exhibit that the composite structures with proper distribution of materials and orientations are of more stable performance when the load fluctuates.
Gao, Y, Feng, Z, Fang, J & Wang, S 2016, 'Research on the Fatigue Durability Performance of a SUV Rear Axle', SAE Technical Papers, SAE World Congress, SAE, Detroit, USA, pp. 1-8.View/Download from: UTS OPUS or Publisher's site
© Copyright 2016 SAE International.The performance of the rear axle plays an important role in the performance of vehicle, and its fatigue durability is an integral part in the vehicle development. Taking a SUV model as the research subject, a new methodology of multi-channel spindle coupled road simulator and fatigue simulation analysis for rear axle assembly was introduced in the paper, aiming to address the fatigue design and its verification for the rear axle in the development phase. Firstly, road loads in the proving ground was collected by arranging proper sensors. Secondly, physical iteration was performed on the multichannel spindle coupled road simulator by taking six component forces at the wheel hub as the target signals. Then, after the time waveform replication of the loads the durability test was conducted. Finally, the validated simulation model was successfully implemented to improve the fatigue life of the axle.
Copyright © 2016 SAE International.As a potential material for lightweight vehicle, polymethyl methacrylate (PMMA) has proven to perform well in optical behavior and weather resistance. However, the application in automotive glazing has seldom been studied. This paper investigates the defrost performance of PMMA rear window using both numerical and experimental methods. The finite element analysis (FEA) results were found to be in good agreement with the experimental data. Based on the validated finite element model, we further optimized the defrost efficiency by changing the arrangement of heating lines. The results demonstrated the frost layer on the vision-related region of PMMA rear window can melt within 30 minutes, which meets the requirement of defrost efficiency.
Fang, J, Xu, F, Sun, G, Li, G, Gao, Y & Li, Q 2014, 'Crashworthiness investigation for functionally graded thickness (FGT) circular column', 8th Australasian Congress on Applied Mechanics, ACAM 2014, as Part of Engineers Australia Convention 2014, Australasian Congress on Applied Mechanics, Informit, Melbourne, Australia, pp. 191-197.View/Download from: UTS OPUS
There has been continuous pursuit of new thin-walled structures in transportation and defense industries recently for more efficient usage of materials in order to achieve light weight and high energy absorption. In this paper, a functionally graded thickness (FGT) tube with a varying wall thickness along axial direction is introduced. The established finite element model of FGT circular tube is validated by performed physical experiments. Numerical analysis demonstrates that gradient exponent controlling the variation of thickness distributions and the thickness interval have significant effect on governing the percentage increase in absorbed-energy. Furthermore, the FGT circular column is found superior to the uniform thickness column in crashworthiness.
Gao, Y, Qiu, N, Fang, J & Wang, S 2014, 'A test method and simulation study of PMMA glazing on motion deviation', SAE Technical Papers, SAE 2014 World Congress & Exhibition.View/Download from: Publisher's site
For achieving vehicle light weighting, the motion deviation is calculated for substitution of PMMA glazing for inorganic glass. In this paper, a test method is proposed to measure and calculate the motion deviation of the dual-curvature glass. To simulate the dual-curvature glass, the torus surface is fitted with least square method according to the window frame data, which are measured by Coordinate Measuring Machine. By using this method, the motion deviation of PMMA glazing and inorganic glass can be calculated, which can not only validate the effectiveness of motion simulation, but also compare the performances. The results demonstrate that the performance of PMMA glazing is better than that of inorganic glass and the simulation results is validated. Copyright © 2014 SAE International.