A large model of the screen was mounted in the laboratory for studying its modal performance. The model is suspended with steel ropes. Modal test was carried out with artificially exciting by 500 g impacting hammer an...A large model of the screen was mounted in the laboratory for studying its modal performance. The model is suspended with steel ropes. Modal test was carried out with artificially exciting by 500 g impacting hammer and 100 kg exciting force shaker respectively. Synthesis and correction of the modal parameters are obtained from both testing methods. Design faults of vibrating screen were determined based on the analy-sis and dynamic correction of structure approaches about the screen was put forward finally.展开更多
The aim of this paper is to conduct experimental modal analysis and numerical simulation to verify the structural characteristics of a deployable-retractable wing for aircraft and spacecraft. A modal impact test was c...The aim of this paper is to conduct experimental modal analysis and numerical simulation to verify the structural characteristics of a deployable-retractable wing for aircraft and spacecraft. A modal impact test was conducted in order to determine the free vibration characteristics. Natural frequencies and vibration mode shapes were obtained via measurement in LMS Test. Lab. The frequency response functions were identified and computed by force and acceleration signals, and then mode shapes of this morphing wing structure were subsequently identified by PolyMAX modal parameter estimation method. FEM modal analysis was also implemented and its numerical results convincingly presented the mode shape and natural frequency characteristics were in good agreement with those obtained from experimental modal analysis. Experimental study in this paper focuses on the transverse response of morphing wing as its moveable part is deploying or retreating. Vibration response to different rotation speeds have been collected, managed and analyzed through the use of comparison methodology with each other. Evident phenomena have been discovered including the resonance on which most analysis is focused because of its potential use to generate large amplitude vibration of specific frequency or to avoid such resonant frequencies from a wide spectrum of response. Manufactured deployable-retractable wings are studied in stage of experimental modal analysis, in which some nonlinear vibration resulted should be particularly noted because such wing structure displays a low resonant frequency which is always optimal to be avoided for structural safety and stability.展开更多
Because of the limited space of the launch rockets, deployable mechanisms are always used to solve the phenomenon. One dimensional deployable mast can deploy and support antenna, solar sail and space optical camera. T...Because of the limited space of the launch rockets, deployable mechanisms are always used to solve the phenomenon. One dimensional deployable mast can deploy and support antenna, solar sail and space optical camera. Tape-spring hyperelastic hinges can be folded and extended into a rod like configuration. It utilizes the strain energy to realize self-deploying and drive the other structures. One kind of triangular prism mast with tape-spring hyperelastic hinges is proposed and developed. Stretching and compression stiffness theoretical model are established with considering the tape-spring hyperelastic hinges based on static theory. The finite element model of ten-module triangular prism mast is set up by ABAQUS with the tape-spring hyperelastic hinge and parameter study is performed to investigate the influence of thickness, section angle and radius. Two-module TPM is processed and tested the compression stiffness by the laser displacement sensor, deploying repeat accuracy by the high speed camera, modal shape and fundamental frequency at cantilever position by LMS multi-channel vibration test and analysis system, which are used to verify precision of the theoretical and finite element models of ten-module triangular prism mast with the tape-spring hyperelastic hinges. This research proposes an innovative one dimensional triangular prism with tape-spring hyperelastic hinge which has great application value to the space deployable mechanisms.展开更多
A dynamic load identification model of structural system based on the gener-alized orthogonal polynomial theory is provided, and the least Square discrete algorithm foridentifying the dynamic load is supplied. The mai...A dynamic load identification model of structural system based on the gener-alized orthogonal polynomial theory is provided, and the least Square discrete algorithm foridentifying the dynamic load is supplied. The main key is that the convolution relationsbetween the input and output of the system in time domain are transformed into linear oP-erators in generalized orthogonal domain. The new theory is fully tested and verified bythe dynamic analysis l 'modal test and dynamic load identification teSt of a simulation speci-men- It is shown that the method has some advantages, such as the simple dynamic cali-bration test, the high identification accuracy, especially for the transient load with shortsampling. These are very useful in engineering applications.展开更多
The chassis frame of a heavy lectra haul is analysed by both modal experiment method and finite element method (FEM ) . The first ten order modal parameters of the chassis frame have been obtained satisfactorily. Thes...The chassis frame of a heavy lectra haul is analysed by both modal experiment method and finite element method (FEM ) . The first ten order modal parameters of the chassis frame have been obtained satisfactorily. These parameters have important reference value in designing the chassis frame properly and provide a necessary basis for the fault diagnostics of the truck.展开更多
A hybrid numerical-experimental approach to identify elastic modulus of a textile composite panel using vibration test data is proposed and investi- gated. Homogenization method is adopted to predict the initial value...A hybrid numerical-experimental approach to identify elastic modulus of a textile composite panel using vibration test data is proposed and investi- gated. Homogenization method is adopted to predict the initial values of elastic parameters of the composite, and parameter identification is transformed to an optimization problem in which the objective function is the minimization of the discrepancies between the experimental and numerical modal data. Case study is conducted employing a woven fabric reinforced composite panel. Three parameters （Ell, E22, G12） with higher sensitivities are selected to be identified. It is shown that the elastic parameters can be accurately identified from experimental modal data.展开更多
基金Supported by Provincial Natural Science Foundation of Shanxi(20031046)
文摘A large model of the screen was mounted in the laboratory for studying its modal performance. The model is suspended with steel ropes. Modal test was carried out with artificially exciting by 500 g impacting hammer and 100 kg exciting force shaker respectively. Synthesis and correction of the modal parameters are obtained from both testing methods. Design faults of vibrating screen were determined based on the analy-sis and dynamic correction of structure approaches about the screen was put forward finally.
文摘The aim of this paper is to conduct experimental modal analysis and numerical simulation to verify the structural characteristics of a deployable-retractable wing for aircraft and spacecraft. A modal impact test was conducted in order to determine the free vibration characteristics. Natural frequencies and vibration mode shapes were obtained via measurement in LMS Test. Lab. The frequency response functions were identified and computed by force and acceleration signals, and then mode shapes of this morphing wing structure were subsequently identified by PolyMAX modal parameter estimation method. FEM modal analysis was also implemented and its numerical results convincingly presented the mode shape and natural frequency characteristics were in good agreement with those obtained from experimental modal analysis. Experimental study in this paper focuses on the transverse response of morphing wing as its moveable part is deploying or retreating. Vibration response to different rotation speeds have been collected, managed and analyzed through the use of comparison methodology with each other. Evident phenomena have been discovered including the resonance on which most analysis is focused because of its potential use to generate large amplitude vibration of specific frequency or to avoid such resonant frequencies from a wide spectrum of response. Manufactured deployable-retractable wings are studied in stage of experimental modal analysis, in which some nonlinear vibration resulted should be particularly noted because such wing structure displays a low resonant frequency which is always optimal to be avoided for structural safety and stability.
基金Supported by National Natural Science Foundation of China(Grant No.51605001)Joint Funds of the National Natural Science Foundation of China(Grant No.U1637207)Anhui University Research Foundation for Doctor(Grant No.J01003222)
文摘Because of the limited space of the launch rockets, deployable mechanisms are always used to solve the phenomenon. One dimensional deployable mast can deploy and support antenna, solar sail and space optical camera. Tape-spring hyperelastic hinges can be folded and extended into a rod like configuration. It utilizes the strain energy to realize self-deploying and drive the other structures. One kind of triangular prism mast with tape-spring hyperelastic hinges is proposed and developed. Stretching and compression stiffness theoretical model are established with considering the tape-spring hyperelastic hinges based on static theory. The finite element model of ten-module triangular prism mast is set up by ABAQUS with the tape-spring hyperelastic hinge and parameter study is performed to investigate the influence of thickness, section angle and radius. Two-module TPM is processed and tested the compression stiffness by the laser displacement sensor, deploying repeat accuracy by the high speed camera, modal shape and fundamental frequency at cantilever position by LMS multi-channel vibration test and analysis system, which are used to verify precision of the theoretical and finite element models of ten-module triangular prism mast with the tape-spring hyperelastic hinges. This research proposes an innovative one dimensional triangular prism with tape-spring hyperelastic hinge which has great application value to the space deployable mechanisms.
文摘A dynamic load identification model of structural system based on the gener-alized orthogonal polynomial theory is provided, and the least Square discrete algorithm foridentifying the dynamic load is supplied. The main key is that the convolution relationsbetween the input and output of the system in time domain are transformed into linear oP-erators in generalized orthogonal domain. The new theory is fully tested and verified bythe dynamic analysis l 'modal test and dynamic load identification teSt of a simulation speci-men- It is shown that the method has some advantages, such as the simple dynamic cali-bration test, the high identification accuracy, especially for the transient load with shortsampling. These are very useful in engineering applications.
文摘The chassis frame of a heavy lectra haul is analysed by both modal experiment method and finite element method (FEM ) . The first ten order modal parameters of the chassis frame have been obtained satisfactorily. These parameters have important reference value in designing the chassis frame properly and provide a necessary basis for the fault diagnostics of the truck.
基金supported by the Program for New Century Excellent Talents in University(NCET11-0086)the National Natural Science Foundation of China(10902024)+1 种基金the Doctoral Program of Higher Education of China(20130092120039)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD-1105007001)
文摘A hybrid numerical-experimental approach to identify elastic modulus of a textile composite panel using vibration test data is proposed and investi- gated. Homogenization method is adopted to predict the initial values of elastic parameters of the composite, and parameter identification is transformed to an optimization problem in which the objective function is the minimization of the discrepancies between the experimental and numerical modal data. Case study is conducted employing a woven fabric reinforced composite panel. Three parameters （Ell, E22, G12） with higher sensitivities are selected to be identified. It is shown that the elastic parameters can be accurately identified from experimental modal data.
