Coilable masts are extensively utilized in aerospace systems owing to their structural simplicity,reliability,and high deployment ratios.However,their application is constrained by compression-twist coupling motion du...Coilable masts are extensively utilized in aerospace systems owing to their structural simplicity,reliability,and high deployment ratios.However,their application is constrained by compression-twist coupling motion during deployment,which induces large structure deformations and displacements.To address this limitation,this study proposes a parallel chiral coilable mast with synergistic control strategies.This design transforms the conventional unidirectional compression-twist motion into a bidirectional synchronous pure sliding deployment.Three pretensioned modes were developed for a single-bay unit based on diagonal constraints,leveraging the critical role of diagonals in achieving structural bistability.A topologyoptimized multi-bay configuration enables directional rotation while maintaining structural stability via pretension modes.By redesigning structural constraints on the top and bottom disks,a decoupling strategy achieves pure linear motion at the top batten frame,significantly expanding the operational envelope.The parallel-designed chiral configuration is developed based on the synergistic control strategies of these two structural constraints.Numerical simulations and experimental validation confirm the effectiveness and feasibility of the synergistic control strategies.The chiral configuration facilitates multifunctional deployment capabilities in geometrically unconstrained environments,demonstrating substantial improvements over conventional designs.展开更多
Metamaterials have exotic physical properties that rely on the construction of their underlying architecture.However,the physical properties of conventional mechanical metamaterials are permanently programmed into the...Metamaterials have exotic physical properties that rely on the construction of their underlying architecture.However,the physical properties of conventional mechanical metamaterials are permanently programmed into their periodic interconnect configurations,resulting in their lack of modularity,scalable fabrication,and programmability.Mechanical metamaterials typically exhibit a single extraordinary mechanical property or multiple extraordinary properties coupled together,making it difficult to realize multiple independent extraordinary mechanical properties.Here,the pixel mechanics metamaterials(PMMs)with multifunctional and reprogrammable properties are developed by arraying uncoupled constrained individual modular mechanics pixels(MPs).The MPs enable controlled conversion between two extraordinary mechanical properties(multistability and compression-torsion coupling deformation).Each MP exhibits 32 independent and reversible room temperature programming configurations.In addition,the programmability of metamaterials is further enhanced by shape memory polymer(SMP)and 4D printing,greatly enriching the design freedom.For the PMM consisting of m×n MPs,it has 32(m×n)independent room temperature programming configurations.The application prospects of metamaterials in the vibration isolation device and energy absorption device with programmable performance have been demonstrated.The vibration isolation frequencies of the MP before and after programming were[0 Hz-5.86 Hz],[0 Hz-13.67 Hz and 306.64 Hz-365.23 Hz].The total energy absorption of the developed PMM can be adjusted controllably in the range of 1.01 J-3.91 J.Six standard digital logic gates that do not require sustained external force are designed by controlling the closure between the modules.This design paradigm will facilitate the further development of multifunctional and reprogrammable metamaterials.展开更多
基金supported by the National Key R&D Program of China(Grant No.2018YFB1304600)the CAS Interdisciplinary Innovation Team(Grant No.JCTD-2018-11)the National Natural Science Foundation of China(Grant No.51775541)。
文摘Coilable masts are extensively utilized in aerospace systems owing to their structural simplicity,reliability,and high deployment ratios.However,their application is constrained by compression-twist coupling motion during deployment,which induces large structure deformations and displacements.To address this limitation,this study proposes a parallel chiral coilable mast with synergistic control strategies.This design transforms the conventional unidirectional compression-twist motion into a bidirectional synchronous pure sliding deployment.Three pretensioned modes were developed for a single-bay unit based on diagonal constraints,leveraging the critical role of diagonals in achieving structural bistability.A topologyoptimized multi-bay configuration enables directional rotation while maintaining structural stability via pretension modes.By redesigning structural constraints on the top and bottom disks,a decoupling strategy achieves pure linear motion at the top batten frame,significantly expanding the operational envelope.The parallel-designed chiral configuration is developed based on the synergistic control strategies of these two structural constraints.Numerical simulations and experimental validation confirm the effectiveness and feasibility of the synergistic control strategies.The chiral configuration facilitates multifunctional deployment capabilities in geometrically unconstrained environments,demonstrating substantial improvements over conventional designs.
基金the financial support provided by the National Key R&D Program of China(2022YFB3805700)the National Natural Science Foundation of China(Grant Nos.12072094 and 12172106)+2 种基金the China Postdoctoral Science Foundation(Grant No.2023M730869)the Heilongjiang Natural Science Foundation Joint Guidance Project(Grant No.LH2023A004)the Postdoctoral Fellowship Program of CPSF(Grant No.GZB20230959)。
文摘Metamaterials have exotic physical properties that rely on the construction of their underlying architecture.However,the physical properties of conventional mechanical metamaterials are permanently programmed into their periodic interconnect configurations,resulting in their lack of modularity,scalable fabrication,and programmability.Mechanical metamaterials typically exhibit a single extraordinary mechanical property or multiple extraordinary properties coupled together,making it difficult to realize multiple independent extraordinary mechanical properties.Here,the pixel mechanics metamaterials(PMMs)with multifunctional and reprogrammable properties are developed by arraying uncoupled constrained individual modular mechanics pixels(MPs).The MPs enable controlled conversion between two extraordinary mechanical properties(multistability and compression-torsion coupling deformation).Each MP exhibits 32 independent and reversible room temperature programming configurations.In addition,the programmability of metamaterials is further enhanced by shape memory polymer(SMP)and 4D printing,greatly enriching the design freedom.For the PMM consisting of m×n MPs,it has 32(m×n)independent room temperature programming configurations.The application prospects of metamaterials in the vibration isolation device and energy absorption device with programmable performance have been demonstrated.The vibration isolation frequencies of the MP before and after programming were[0 Hz-5.86 Hz],[0 Hz-13.67 Hz and 306.64 Hz-365.23 Hz].The total energy absorption of the developed PMM can be adjusted controllably in the range of 1.01 J-3.91 J.Six standard digital logic gates that do not require sustained external force are designed by controlling the closure between the modules.This design paradigm will facilitate the further development of multifunctional and reprogrammable metamaterials.
