The use of piezoelectric material sensors in smart composite structures is investigated. An experimental structure bonded with lead zirconate titanate piezoelectric ceramic(PZT) sensors is developed. These bonded sens...The use of piezoelectric material sensors in smart composite structures is investigated. An experimental structure bonded with lead zirconate titanate piezoelectric ceramic(PZT) sensors is developed. These bonded sensors are employed to monitor load variations and transient impacts in the structure. Incorporated with pattern recognition approach, PZT sensors have succeeded in detecting the onset and location of damages.展开更多
Smart structures have the advantages of high system integrity and diverse sensing capabilities.However,the labor-intensive and timeconsuming fabrication process hinders the large-scale adoption of smart structures.Des...Smart structures have the advantages of high system integrity and diverse sensing capabilities.However,the labor-intensive and timeconsuming fabrication process hinders the large-scale adoption of smart structures.Despite recent attempts to develop sensorembedded structures using 3D printing technologies,the reported smart structures generally suffer from the complex fabrication process,constrained part size,and limited sensing modality.Herein,we propose a workflow to design and fabricate novel smart structures via multi-material fused deposition modeling(FDM)-based 3D printing.More specifically,conductive filaments with tailorable mechanical and elec-trical properties,e.g.piezoresistive effects,were developed.Additionally,the printing process was optimized for processing soft filaments with Young’s modulus around 2 MPa,resolving the issue of filament buckling.Furthermore,the potential applications of the proposed workflow were showcased using three design cases,i.e.biaxial strain sensor,smart tire,and cable-driven soft finger with multiple sensing capabilities.This workflow provides a cost-effective and rapid solution for developing novel smart structures with soft materials.展开更多
In the work of developing extrinsic fabry perot interferometric (EFPI), the key technology of polishing fiber optic endfaces and coating the multilayer of dielectric films on them is raised and resolved to settle the...In the work of developing extrinsic fabry perot interferometric (EFPI), the key technology of polishing fiber optic endfaces and coating the multilayer of dielectric films on them is raised and resolved to settle the disturbance and stability problem of EFPI, which simplifies the sensing system, improves the sensor performance and reduces the cost. In this paper, the relations between the output interferential light intensity and the F P cavity length are calculated based on the theory of mode field coupling. The EFPI fiber optic sensor is adhered to a distributed smart laminate beam to detect vibration frequency and axial strain value, the results coincident with the results tested by PZT.展开更多
In this paper numerical simulations of active vibration control for conical shell structure with dis-tributed piezoelectric actuators is presented.The dynamic equations of conical shell structure are derivedusing the ...In this paper numerical simulations of active vibration control for conical shell structure with dis-tributed piezoelectric actuators is presented.The dynamic equations of conical shell structure are derivedusing the finite element model (FEM) based on Mindlin's plate theory.The results of modal calculationswith FEM model are accurate enough for engineering applications in comparison with experiment results.The Electromechanical influence of distributed piezoelectric actuators is treated as a boundary conditionfor estimating the control force.The independent modal space control (IMSC) method is adopted and theoptimal linear quadratic state feedback control is implemented so that the best control performance withthe least control cost can be achieved.Optimal control effects are compared with controlled responses withother non-optimal control parameters.Numerical simulation results are given to demonstrate the effective-ness of the control scheme.展开更多
The space sheet for a solar array structure is large in dimension, and flexible to induce complex distortion. It is difficult to measure the distortion. A large-scale flexible test prototype system is built for sheet ...The space sheet for a solar array structure is large in dimension, and flexible to induce complex distortion. It is difficult to measure the distortion. A large-scale flexible test prototype system is built for sheet structure vibration monitoring based on the vibration information of the solar array in space. The system provides an intelligent test method for flexible space structure with embedded sensors and non-visualization reinstruction. Multiple fiber Bragg grating （FBG） sensors are packaged and embedded into the structure with spatial division multiplexing （SDM） and wavelength division multiplexing （WDM）. The sensor interrogator distinguishes wavelength shifts that can be turned into curvature of the curve. The structure shape is reconstructed based on the curvature information and the arc-length, and then displayed. The experiment shows that the system has a high FBG sensitivity. The reconstruction algorithm is fast with high precision. The system has great potential for use in health monitoring of the space sheet structure.展开更多
探讨了一种压电智能结构的设计方法,包括动力学建模、控制器设计和闭环系统有限元仿真。首先采用有限元方法计算滤过白噪声激励下压电智能结构的响应,以此响应作为系统辨识方法的输入,采用基于观测器/K a lm an滤波器的系统辨识方法(O b...探讨了一种压电智能结构的设计方法,包括动力学建模、控制器设计和闭环系统有限元仿真。首先采用有限元方法计算滤过白噪声激励下压电智能结构的响应,以此响应作为系统辨识方法的输入,采用基于观测器/K a lm an滤波器的系统辨识方法(O bserver/K a lm an filter iden tification,OK ID)得到系统的M arkov参数,亦即单位脉冲响应的采样值,然后采用特征系统实现算法(E igensystem R ea lization A lgorithm,ERA)得到系统的最小实现,基于此模型采用LQG优化算法设计鲁棒控制器,并将反馈控制引入有限元模型进行闭环系统仿真,根据仿真结果评价设计方案。此方法克服了有限元模型无法直接用于控制器设计的缺点,通过将反馈控制引入有限元模型,可用有限元方法研究控制器的性能,也适用于设计其它复杂智能结构。展开更多
文摘The use of piezoelectric material sensors in smart composite structures is investigated. An experimental structure bonded with lead zirconate titanate piezoelectric ceramic(PZT) sensors is developed. These bonded sensors are employed to monitor load variations and transient impacts in the structure. Incorporated with pattern recognition approach, PZT sensors have succeeded in detecting the onset and location of damages.
基金This work was supported by the National Key Research and Development Program of China[No.2020YFB1312900]National Natural Science Foundation of China[No.52105261]Guangdong Basic and Applied Basic Research Foundation[No.2022A1515010316].
文摘Smart structures have the advantages of high system integrity and diverse sensing capabilities.However,the labor-intensive and timeconsuming fabrication process hinders the large-scale adoption of smart structures.Despite recent attempts to develop sensorembedded structures using 3D printing technologies,the reported smart structures generally suffer from the complex fabrication process,constrained part size,and limited sensing modality.Herein,we propose a workflow to design and fabricate novel smart structures via multi-material fused deposition modeling(FDM)-based 3D printing.More specifically,conductive filaments with tailorable mechanical and elec-trical properties,e.g.piezoresistive effects,were developed.Additionally,the printing process was optimized for processing soft filaments with Young’s modulus around 2 MPa,resolving the issue of filament buckling.Furthermore,the potential applications of the proposed workflow were showcased using three design cases,i.e.biaxial strain sensor,smart tire,and cable-driven soft finger with multiple sensing capabilities.This workflow provides a cost-effective and rapid solution for developing novel smart structures with soft materials.
文摘In the work of developing extrinsic fabry perot interferometric (EFPI), the key technology of polishing fiber optic endfaces and coating the multilayer of dielectric films on them is raised and resolved to settle the disturbance and stability problem of EFPI, which simplifies the sensing system, improves the sensor performance and reduces the cost. In this paper, the relations between the output interferential light intensity and the F P cavity length are calculated based on the theory of mode field coupling. The EFPI fiber optic sensor is adhered to a distributed smart laminate beam to detect vibration frequency and axial strain value, the results coincident with the results tested by PZT.
基金the National Defense Advanced Research Project(No.41320020302)
文摘In this paper numerical simulations of active vibration control for conical shell structure with dis-tributed piezoelectric actuators is presented.The dynamic equations of conical shell structure are derivedusing the finite element model (FEM) based on Mindlin's plate theory.The results of modal calculationswith FEM model are accurate enough for engineering applications in comparison with experiment results.The Electromechanical influence of distributed piezoelectric actuators is treated as a boundary conditionfor estimating the control force.The independent modal space control (IMSC) method is adopted and theoptimal linear quadratic state feedback control is implemented so that the best control performance withthe least control cost can be achieved.Optimal control effects are compared with controlled responses withother non-optimal control parameters.Numerical simulation results are given to demonstrate the effective-ness of the control scheme.
基金Project supported by the National Natural Science Foundation China (Grant No.90405013)
文摘The space sheet for a solar array structure is large in dimension, and flexible to induce complex distortion. It is difficult to measure the distortion. A large-scale flexible test prototype system is built for sheet structure vibration monitoring based on the vibration information of the solar array in space. The system provides an intelligent test method for flexible space structure with embedded sensors and non-visualization reinstruction. Multiple fiber Bragg grating （FBG） sensors are packaged and embedded into the structure with spatial division multiplexing （SDM） and wavelength division multiplexing （WDM）. The sensor interrogator distinguishes wavelength shifts that can be turned into curvature of the curve. The structure shape is reconstructed based on the curvature information and the arc-length, and then displayed. The experiment shows that the system has a high FBG sensitivity. The reconstruction algorithm is fast with high precision. The system has great potential for use in health monitoring of the space sheet structure.
文摘探讨了一种压电智能结构的设计方法,包括动力学建模、控制器设计和闭环系统有限元仿真。首先采用有限元方法计算滤过白噪声激励下压电智能结构的响应,以此响应作为系统辨识方法的输入,采用基于观测器/K a lm an滤波器的系统辨识方法(O bserver/K a lm an filter iden tification,OK ID)得到系统的M arkov参数,亦即单位脉冲响应的采样值,然后采用特征系统实现算法(E igensystem R ea lization A lgorithm,ERA)得到系统的最小实现,基于此模型采用LQG优化算法设计鲁棒控制器,并将反馈控制引入有限元模型进行闭环系统仿真,根据仿真结果评价设计方案。此方法克服了有限元模型无法直接用于控制器设计的缺点,通过将反馈控制引入有限元模型,可用有限元方法研究控制器的性能,也适用于设计其它复杂智能结构。
