Browsing by Author "Li, Zhou"

Now showing 1 - 6 of 6
  • Thumbnail Image
    ItemOpen Access
    Compressive properties and fracture behaviours of Ti/Al interpenetrating phase composites with additive-manufactured triply periodic minimal surface porous structures
    (Springer, 2024-12-31) Li, Zhou; Mo, Haotian; Tian, Jiahao; Li, Junhao; Xia, Shiqi; Jia, Xianshi; Zhou, Libo; Lu, Yao
    The triply periodic minimal surfaces (TPMS) structure is regarded as a highly promising artificial design, but the performance of composites constructed using this structure remains unexplored. Two porosity levels of Ti/Al interpenetrating phase composites (IPCs) were fabricated by infiltrating ZL102-Al melt into additive-manufactured TC4-Ti scaffolds with the TPMS porous in this study. The combination of the two-phase alloys exhibits structural integrity at the interfacial region, as evidenced by microscopic surfaces observed in uncompressed IPCs. Quasi-static compression tests were performed to demonstrate that the Young’s modulus, yield stress and maximum compressive stress of IPCs exhibit significant enhancement when compared to the individual TPMS scaffolds, due to the supporting and strengthening effect of the filling phase. In the compression process of IPCs, defects emerge initially at the interface between the ZL102 phase and TC4 phase, triggering the fracture and slip of the ZL102 phase, eventually propagating to involve fracture in the TC4 phase. The deformation behaviours obtained from numerical simulation were combined to support these experimental phenomena. The results show that the corresponding stress concentration region is the central region of the spiral surface, the maximum stress concentration region of the ZL102 phase is the same as that of the TC4 phase, and the ZL102 phase effectively shares part of the loading. The Ti/Al IPCs achieve equivalent load-bearing capacity through a simplified interpenetration process and the utilisation of lighter materials.
  • Thumbnail Image
    ItemOpen Access
    Design of nonlinear gradient sheet-based TPMS-lattice using artificial neural networks
    (Elsevier, 2024-11-01) Li, Zhou; Li, Junhao; Tian, Jiahao; Xia, Shiqi; Li, Kai; Su, Guanqiao; Lu, Yao; Ren, Mengyuan; Jiang, Zhengyi
    Gradient triply periodic minimal surface (TPMS) structures are renowned for lightweight design and enhanced performance, but their complex and nonlinear configurations pose challenges in achieving targeted design goals. A new design methodology for the nonlinear gradient structure was proposed in this study, with the aim of achieving efficient and accurate modeling of complex and gradient sheet-based TPMS structures under specific performance objectives. This method utilized automated finite element (FE) simulations to obtain structure topology element densities under various boundary conditions. An artificial neural network (ANN) was then employed to efficiently predict the correspondence between these boundary conditions and topology element densities. A mapping was established between topology element densities and TPMS structural parameters, and the gradient structure was accurately constructed by using the voxel modeling technique. Taking a typical cantilever beam TPMS structure as an example of nonlinear gradient design, the results indicate that the error between the ANN-predicted and FE-simulated structure topology element densities is only 2.73 %, with prediction time being only 0.15 % of the simulation time. The thin regions of the gradient structure align with those geometrically removed in regular topology optimization scheme, achieving up to 65.45 % weight reduction, a 28.72 % improvement over the regular scheme, along with uniform structural stress transition and maximum stress reduction. TC4 alloy nonlinear gradient TPMS structures, printed by metal selective laser melting (SLM) technique, confirm the practical application value of this design method.
  • Thumbnail Image
    ItemOpen Access
    Enhanced performance of micro deep drawing through the application of TiO2 nanolubricant and graphene lubricants on SUS 301 stainless steel foil
    (MDPI, 2023-10-23) Pan, Di; Zhang, Guangqing; Jia, Fanghui; Lu, Yao; Wang, Jun; Li, Zhou; Li, Lianjie; Yang, Ming; Jiang, Zhengyi
    first_pagesettingsOrder Article Reprints Open AccessArticle Enhanced Performance of Micro Deep Drawing through the Application of TiO2 Nanolubricant and Graphene Lubricants on SUS 301 Stainless Steel Foil by Di Pan 1ORCID,Guangqing Zhang 1,Fanghui Jia 1,Yao Lu 2,Jun Wang 2,Zhou Li 3,Lianjie Li 4,Ming Yang 5ORCID andZhengyi Jiang 1,* 1 School of Mechanical, Materials, Mechatronic and Biomedical Engineering, Wollongong, NSW 2522, Australia 2 Welding Engineering and Laser Processing Centre, Cranfield University, Bedfordshire MK43 0AL, UK 3 College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China 4 School of Intelligent Manufacturing and Control Engineering, Shanghai Polytechnic University, Shanghai 201209, China 5 Graduate School of System Design, Tokyo Metropolitan University, Hino, Tokyo 191-0055, Japan * Author to whom correspondence should be addressed. Processes 2023, 11(10), 3042; https://doi.org/10.3390/pr11103042 Received: 2 September 2023 / Revised: 17 October 2023 / Accepted: 20 October 2023 / Published: 23 October 2023 (This article belongs to the Special Issue Processing, Manufacturing and Properties of Metal and Alloys) Downloadkeyboard_arrow_down Browse Figures Versions Notes Abstract In recent years, the quest for effective lubrication in micro deep drawing (MDD) has seen promising advancements. In this study, the influence of TiO2 nanolubricants and graphene lubricants on the performance of 301 stainless steel foil in MDD is examined. The MDD undergoes an extensive evaluation of various lubrication conditions, including dry, TiO2 nanolubricant, graphene lubricant at concentrations of 2.5 mg/mL, 5.0 mg/mL, and 10.0 mg/mL, as well as combined applications of TiO2 and graphene lubricants. Utilising a 5.0 mg/mL graphene lubricant together with TiO2 nanolubricants led to a significant reduction in drawing force, highlighting the synergistic efficacy of this combined lubricant. A pronounced enhancement in the consistency of the produced microcups was also attained. These results emphasise the promise of TiO2 nanolubricant and graphene lubricants in optimising the MDD process.
  • Thumbnail Image
    ItemOpen Access
    Gas turbine transient performance simulation, control and optimisation
    (2016-04) Li, Zhou; Nikolaidis, Theoklis; Zachos, Pavlos K.
    A gas turbine engine is a complex and non-linear system. Its dynamic response changes at different operating points. The exogenous inputs: atmospheric conditions and Mach number, also add disturbances and uncertainty to the dynamic. To satisfy the transient time response as well as safety requirements for its entire operating range is a challenge for control system design in the gas turbine industry. Although the recent design of engine control units includes some advanced control techniques to increase its control robustness and adaptability to the changing environment, the classic scheduling technique still plays the decisive role in determining the control values due to its better reliability under normal circumstances. Producing the schedules requires iterative experiments or simulations in all possible circumstances for obtaining the optimal engine performance. The techniques, such as scheduling method or linear control methods, are still lack of development for control of transient performance on most commercial simulation tools. Repetitive simulations are required to adjust the control values in order to obtain the optimal transient performance. In this project, a generalised model predictive controller was developed to achieve an online transient performance optimisation for the entire operating range. The optimal transient performance is produced by the controller according to the predictions of engine dynamics with consideration of constraints. The validation was conducted by the application of the control system on the simulated engines. The engines are modelled to component-level by the inter-component volume method. The results show that the model predictive controller introduced in this project is capable of providing the optimal transient time response as well as operating the engine within the safety margins under constant or varying environmental conditions. In addition, the dynamic performance can be improved by introducing additional constraints to engine parameters for the specification of smooth power transition as well as fuel economy.
  • Thumbnail Image
    ItemOpen Access
    Inverse design of cellular structures with the geometry of triply periodic minimal surfaces using generative artificial intelligence algorithms
    (Elsevier, 2024-12-15) Li, Zhou; Li, Junhao; Tian, Jiahao; Xia, Shiqi; Li, Kai; Li, Maojun; Lu, Yao; Ren, Mengyuan; Jiang, Zhengyi
    Triply periodic minimal surfaces (TPMS) exhibit excellent mechanical and energy absorption properties due to their structural advantages. However, existing porous TPMS structural design methods are constrained to a forward process from structural parameters to mechanical properties. This study proposed an inverse design method that combines bidirectional generative adversarial networks (BiGAN) and mechanical performance targets, resulting in a combined TPMS structure of Primitive and IWP types with superior buffering and energy absorption capabilities. The results show that under a single load value target condition of the designed structure, the minimum deviation index (R2) between the load value corresponding to the displacement point and the target load value is only 0.987, and the maximum mean absolute percentage error (MAPE) is only 5.92 %. When considering the elastic modulus target, the approach successfully conducts two sets of combined structural designs meeting the requirements of both high and low elastic moduli. When targeting the specified load-displacement curve conditions, specifically when combining high elastic modulus with ascending plasticity, the designed structures exhibit an error of only 2.2 % compared to the target property. Moreover, the quasi-static uniaxial compression experiments conducted on additively manufactured designed structures confirm that the experimental curves match the target curves in terms of deformation trends and load value ranges. The success of this inverse design approach for cellular TPMS structures has the potential to expedite new structural material development processes.
  • Thumbnail Image
    ItemOpen Access
    A novel Ti/Al interpenetrating phase composite with enhanced mechanical properties
    (Elsevier, 2023-12-09) Li, Zhou; Mo, Haotian; Tian, Jiahao; Li, Jiahao; Hu, Xiao; Xia, Shiqi; Lu, Yao; Jiang, Zhengyi
    Lightweight, energy-absorbing materials with excellent mechanical properties are highly desired in practical engineering applications. A novel Ti-Al interpenetrating phase composite (Ti/Al IPC) was successfully fabricated by filling an Al alloy (ZL102) in the pores of an additively manufactured triply periodic minimal surface (TPMS) structure composed of Ti alloy (TC4). This IPC demonstrates a remarkable combination of attributes, including a high yield stress of 305 MPa, a Young's modulus of 64 GPa, and an ultimate tensile strength of 420 MPa. These mechanical properties are 1.5 to 2.9 times stronger than those of a single TC4 TPMS structure of the same size. The enhanced performance can be attributed to the synergistic strengthening and toughening effect resulting from the internal interpenetration of the ZL102 phase within the structure.