A new appraisal method(QDA, quasi-distribution appraisal) which could be used to evaluate the finite element analysis of multi-functional structure made of honeycomb sandwich materials is developed based on sub-sect...A new appraisal method(QDA, quasi-distribution appraisal) which could be used to evaluate the finite element analysis of multi-functional structure made of honeycomb sandwich materials is developed based on sub-section Bezier curve. It is established by simulating the distribution histogram data obtained from the numerical finite element analysis values of a satellite component with sub-section Bezier curve. Being dealt with area normalization method, the simulation curve could be regarded as a kind of probability density function(PDF), its mathematical expectation and the variance could be used to evaluate the result of finite element analysis. Numerical experiments have indicated that the QDA method demonstrates the intrinsic characteristics of the finite element analysis of multi-functional structure made of honeycomb sandwich materials, as an appraisal method, it is effective and feasible.展开更多
Recent years have witnessed rapid progress in calculating parton distribution functions (PDFs), rather than just their moments, from lattice QCD [1-9]. The most remarkable aspect of such calculations is that one can c...Recent years have witnessed rapid progress in calculating parton distribution functions (PDFs), rather than just their moments, from lattice QCD [1-9]. The most remarkable aspect of such calculations is that one can connect appropriately chosen Euclidean correlation functions calculable on the lattice to PDFs through a perturbative matching relation. This can be understood in the framework of the large-momentum effective theory (LaMET)[10, 11].展开更多
To monitor the stress state of prestressed reinforcement in large reinforcement prestressed structure, two sensing structures, namely the direct spiral-winding structure and sawtooth modulated structure, were designed...To monitor the stress state of prestressed reinforcement in large reinforcement prestressed structure, two sensing structures, namely the direct spiral-winding structure and sawtooth modulated structure, were designed based on the ordinary communication optical fiber. The sensing theories were analyzed, and the experimental studies were also carried out. The quasi-distributed sensing system based on optical time domain reflective technology was established. The detection wavelength and spatial resolution were analyzed, and the estimation formula of maximal number of sensing point was also given. The results show that the system can realize the quasi-distributed test of measurand with single fiber, which helps to simplify the in-out wires. Moreover it can take on the important task of long-term and continuous monitoring of prestress, which helps to realize the life cycle detection of prestress, and play an important role in the estimating of bridge health state.展开更多
Electrical sensing systems, such as those involving eutectic salt, are mostly used in connection to leakage from existing airborne high-temperature air-conducting pipelines. Such complex structured systems are suscept...Electrical sensing systems, such as those involving eutectic salt, are mostly used in connection to leakage from existing airborne high-temperature air-conducting pipelines. Such complex structured systems are susceptible to external interferences and, thus, cannot meet the increasingly strict monitoring needs of a complex air-conducting pipeline system of an aircraft. In view of this point, this paper studies an alternative sensor system based on a dense array fiber grating. To obtain a compact and light-weight airborne signal processing system, a field programmable gate array is used as the main control core that controls the output of the light source. The functions of pulse modulation, analog-to-digital conversion,data buffering and transmission are integrated into a single system, while the linear sensing monitoring is obtained by detecting the time-division and wavelength-division wavelength drift signals of the fiber Bragg grating array. Our experiments show that the spatial resolution of the linear sensing system approaches 5 cm, the temperature measurement accuracy reaches 2 ℃, the temperature measurement range is between 0–250 ℃, and the response time is within 4 s. Compared with the existing electrical monitoring systems, various monitoring indicators have been greatly improved and have broad application prospects.展开更多
基金Funded by the National Natural Science Foundation of China(No.61471024)National Marine Technology Program for Public Welfare,China(No.201505002-1)
文摘A new appraisal method(QDA, quasi-distribution appraisal) which could be used to evaluate the finite element analysis of multi-functional structure made of honeycomb sandwich materials is developed based on sub-section Bezier curve. It is established by simulating the distribution histogram data obtained from the numerical finite element analysis values of a satellite component with sub-section Bezier curve. Being dealt with area normalization method, the simulation curve could be regarded as a kind of probability density function(PDF), its mathematical expectation and the variance could be used to evaluate the result of finite element analysis. Numerical experiments have indicated that the QDA method demonstrates the intrinsic characteristics of the finite element analysis of multi-functional structure made of honeycomb sandwich materials, as an appraisal method, it is effective and feasible.
基金supported by the Science and Technology Commission of Shanghai Municipality(Grant No.16DZ2260200)supported by the Department of Energy,Laboratory Directed Research and Development(LDRD)funding of BNL(Grant No.DE-EC0012704)+3 种基金supposed by the US National Science Foundation(Grant No.PHY 1653405)supported by the SFB/TRR-55 Grant “Hadron Physics from Lattice QCD”supported by the National Natural Science Foundation of China(Grant No.11405104)supported by the US Department of Energy,Office of Science,Office of Nuclear Physics,from DE-SC0011090 and within the framework of the TMD Topical Collaboration
文摘Recent years have witnessed rapid progress in calculating parton distribution functions (PDFs), rather than just their moments, from lattice QCD [1-9]. The most remarkable aspect of such calculations is that one can connect appropriately chosen Euclidean correlation functions calculable on the lattice to PDFs through a perturbative matching relation. This can be understood in the framework of the large-momentum effective theory (LaMET)[10, 11].
文摘To monitor the stress state of prestressed reinforcement in large reinforcement prestressed structure, two sensing structures, namely the direct spiral-winding structure and sawtooth modulated structure, were designed based on the ordinary communication optical fiber. The sensing theories were analyzed, and the experimental studies were also carried out. The quasi-distributed sensing system based on optical time domain reflective technology was established. The detection wavelength and spatial resolution were analyzed, and the estimation formula of maximal number of sensing point was also given. The results show that the system can realize the quasi-distributed test of measurand with single fiber, which helps to simplify the in-out wires. Moreover it can take on the important task of long-term and continuous monitoring of prestress, which helps to realize the life cycle detection of prestress, and play an important role in the estimating of bridge health state.
文摘Electrical sensing systems, such as those involving eutectic salt, are mostly used in connection to leakage from existing airborne high-temperature air-conducting pipelines. Such complex structured systems are susceptible to external interferences and, thus, cannot meet the increasingly strict monitoring needs of a complex air-conducting pipeline system of an aircraft. In view of this point, this paper studies an alternative sensor system based on a dense array fiber grating. To obtain a compact and light-weight airborne signal processing system, a field programmable gate array is used as the main control core that controls the output of the light source. The functions of pulse modulation, analog-to-digital conversion,data buffering and transmission are integrated into a single system, while the linear sensing monitoring is obtained by detecting the time-division and wavelength-division wavelength drift signals of the fiber Bragg grating array. Our experiments show that the spatial resolution of the linear sensing system approaches 5 cm, the temperature measurement accuracy reaches 2 ℃, the temperature measurement range is between 0–250 ℃, and the response time is within 4 s. Compared with the existing electrical monitoring systems, various monitoring indicators have been greatly improved and have broad application prospects.