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Research on Small-Loop Transient Electromagnetic Method Forward and Nonlinear optimization inversion Method

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2023年 61卷 1页

作者： Xu, Zhengyu Liao, Xian Liu, Longhuan Fu, Nengyi Fu, Zhihong Chongqing Univ Sch Elect Engn Chongqing 400044 Peoples R China Univ Tulsa Dept Elect & Comp Engn Tulsa OK 74115 USA

The small-loop transient electromagnetic (TEM) method has great application prospects in shallow surface geophysical exploration. However, the theoretical research on the forward and inversion of this method is obviously lagging behind, which seriously affects the application effect in practical engineering. For the oscillation problem of the small-loop TEM response calculated by using the forward theory of the conventional TEM methods, the dipole integral superposition method was proposed to solve the problem in this article. The transmitter source is divided into an infinite number of electric dipoles, and the calculation expressions of the electromagnetic field components satisfied by the electric dipoles are deduced, and the forward calculation problem of the layered model of the small-loop TEM method is solved. For the small-loop TEM method inversion problem, the simulated annealing (SA) method was presented for inversion calculation in this article. First, the influence of the selection of the initial temperature on the inversion result of the SA algorithm was analyzed. Then, we demonstrate the algorithm's flexibility by choosing different initial models and search ranges and concluded that the different initial models and search ranges do not affect the inversion results of the SA algorithm. Next, the typical layered models were established, and the SA algorithm was used to carry out calculations. The research results show that the SA algorithm is an excellent global optimization algorithm, which can easily jump out of the local minima and converge to the global minima. Finally, we processed the measured data through inversion calculations and compared it with the results of the other three methods to verify the effectiveness and accuracy of the SA algorithm for small-loop TEM data processing. The research content solves the theoretical problem of the small-loop TEM method forward and inversion, promotes the development of the small-loop TEM method technology

关键词： Transmitters optimization Transient analysis Signal processing algorithms Conductivity Data processing Oscillators Forward calculation optimization inversion simulated annealing (SA) small-loop transient electromagnetic (TEM) method

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Evaluation of the mechanical parameters of a reinforced concrete dam based on multi-source data

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STRUCTURAL CONCRETE 2022年第2期23卷 652-668页

作者： Huang, Yaoying Xie, Tong Xu, Yao Wang, Ronglu China Three Gorges Univ Coll Hydraul & Environm Engn Yichang 443002 Peoples R China China Three Gorges Renewables Yangjiang Power Gen Yangjiang Guangdong Peoples R China China Inst Water Resources & Hydropower Res Dept Mat Beijing Peoples R China

In this research, we studied a roller-compacted concrete (RCC) arch dam which was reinforced during the construction period to investigate the properties of mechanical parameters of the dam concrete after long-term operation. Firstly, multiple methods involving core drilling, computerized tomography (CT), spectral analysis of the surface wave (SASW) of elastic waves, and an onsite inspection were adopted to detect the quality of the dam concrete, which was followed by a forward-analysis of the measured displacement of the arch dam and the water pressure component of the measured displacement was separated through regression analysis of statistical model of radial horizontal displacement. Subsequently, an optimization inversion of the elastic modulus of the dam body and dam foundation was conducted using a hybrid optimization method. The results showed that the compressive strength of the concrete in the body of the reinforced arch dam was over 30 MPa and the inversion results for the elastic modulus of the dam body were in the range of 30.1 similar to 33.3 GPa. According to the research results of multi-source inspected and monitoring data during the operation period, the results suggest that the performance of the concrete of the dam body is in accordance with design requirements and the reinforced arch dam is properly operated.

关键词： comprehensive quality inspection measured displacement mechanical parameters optimization inversion reinforced high concrete dam

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Evolution of thermal parameters of wet-screened dam concrete after different freeze-thaw deterioration

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STRUCTURAL CONCRETE 2022年第4期23卷 2185-2197页

作者： Huang, Yaoying Ding, Qian Wang, Yu Liao, Zaiyi Yin, Xiaohui China Three Gorges Univ Coll Hydraul & Environm Engn Yichang 443002 Peoples R China China Three Gorges Corp Relocat Resettlement Off Chengdu Peoples R China Ryerson Univ Dept Architectural Sci Toronto ON Canada

Even with specialized equipment, it is difficult to measure the thermal parameters of dam concrete during freeze-thaw testing. In addition, numerical calculations usually assume that freeze-thaw cycling does not change the thermal parameters of the aggregate and mortar of dam concrete, which makes it difficult to accurately determine how these parameters evolve during freeze-thaw deterioration. To address this challenge, we propose herein a new method to determine the thermal parameters of wet-screened dam concrete during freeze-thaw deterioration. This method involves freeze-thaw testing, temperature perturbation, numerical calculation, and optimization inversion. First, 200 rapid freeze-thaw tests and 5 temperature perturbation tests of 5 concrete specimens were carried out. Next, orthogonal design parameters were used to calculate the temperature field of the specimens via the finite-element method. A neural network was then established based on the difference between the measured and calculated temperatures. The expected difference and measured density were fed into the model to invert the thermal parameters of the concrete for different water-cement ratios, ages, and content of the air-entraining agent. The results show that, upon increasing the number of freeze-thaw cycles, the thermal conductivity of wet-screened dam concrete gradually decreases, the specific heat remains relatively constant, and the surface heat-transfer coefficient gradually increases.

关键词： optimization inversion rapid freeze-thaw temperature perturbation thermal parameters wet-screened dam concrete

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Inversing NOx emissions based on an optimization model that combines a source-receptor relationship correction matrix and monitoring data: A case study in Linyi, China

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ATMOSPHERIC ENVIRONMENT 2024年 338卷

作者： Li, Mengzhen Lang, Jianlei Zhou, Ying Shen, Zeya Chen, Dongsheng Li, Jia Cheng, Shuiyuan Beijing Univ Technol Sch Environm Sci & Engn Key Lab Beijing Reg Air Pollut Control Beijing 100124 Peoples R China Shipbuilding Informat Ctr China Beijing 100124 Peoples R China

comparison with the IMSC. Results showed that the IMSC more accurately, robustly, and reasonably estimated NOx emissions. Compared to the IMWSC, the IMSC improved the mean correlation between NOx x emissions and NO2 2 observational concentrations by 25.0%, enhancing the correlation between NOx emissions and NO2 column concentrations by 111.3%. The similar NOx emission change ratios (6 average = 5.1%) between the typical months in 2021 and 2020 among the different counties indicated a more robust performance of the IMSC than the IMWSC (6 average = 55.2%). In addition, the NOx x emissions inversed by the IMSC also showed better consistency with social activity levels (i.e., electricity consumption). The typical monthly Linyi's county-level NOx x emission characterization was also studied. NOx emissions were lower in April, July, and October 2021 than the same period in 2020 due to COVID-19 and pollution controls. This study provides strategies for swiftly and accurately estimating pollutant emissions.

关键词： optimization inversion Emission inventories Correction matrix Source-receptor WRF-CAMx-PSAT

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Quantitative diagnosis method of the sucker rod pump system based on the fault mechanism and inversion algorithm

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JOURNAL OF PROCESS CONTROL 2021年 104卷 40-53页

作者： Lv Xiaoxiao Feng Long Wang Hanxiang Liu Yanxin Sun Bingyu China Univ Petr Coll Mech & Elect Engn Qingdao 266580 Peoples R China

Computer-aided fault diagnosis based on the dynamometer card (DC) of the sucker-rod pumping system (SRPS) is a crucial technology to reduce operating costs and increase yield. Currently, the conventional method to implement this technology is the pattern recognition of the DC features. However, the training set of DC that determines the diagnostic accuracy of the method is difficult to obtain because of the differences between oil wells. Moreover, this method can only obtain the type of single fault without quantitative analysis, which may affect the formulation of the adjustment measures. Therefore, in the present study, a quantitative diagnosis method independent of the training data is proposed. In order to obtain the operation process of SRPS under the comprehensive conditions of the fault, a simulation model involving fault effects is established according to the fault mechanism. Subsequently, the framework of the optimization inversion method is established to determine the fault parameters by minimizing the difference between the measured DC and the DC generated by the fault-mechanism model. Then, the strategy of the partition parallel optimization is utilized to improve the stability and efficiency of the inversion algorithm. Meanwhile, fifteen indicating parameters that directly reflect the type and degree of faults are defined. Finally, the proposed diagnosis method is verified experimentally through the data of 20 actual wells. The obtained results demonstrate the effectiveness of the proposed method for diagnosing the types of single and coupling faults, as well as predicting the production rate. (C) 2021 Published by Elsevier Ltd.

关键词： Diagnosis Sucker rod pump Multiple fault diagnosis Dynamometer card optimization inversion

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A novel method for determining the stress-strain constitutive relationship of high-grade pipeline weld zone material

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ENGINEERING FAILURE ANALYSIS 2023年第1期150卷

作者： Zhang, Dong Liu, Xiaoben Kong, Tianwei Yang, Yue Fu, Mengkai Wang, Hao Wu, Kai Zhang, Hong China Univ Petr Natl Engn Res Ctr Pipeline Safety MOE Key Lab Petr Engn Beijing Key Lab Urban Oil & Gas Distribut Technol Beijing Peoples R China Hefei Gen Machinery Res Inst Natl Safety Engn Technol Res Ctr Pressure Vessels Hefei Peoples R China

As a typical welding structure, the girth weld of high-grade pipelines has obvious heterogeneity. Therefore, the axial mechanical properties of girth weld materials cannot be accurately tested, and the safety evaluation of the girth weld of the pipeline is seriously affected. Based on MATLAB-PYTHON-ABAQUS co-simulation, an optimization inversion method of the material stress-strain constitutive relationship in the weld zone of the high-grade pipeline is proposed in this paper. Four groups of uniaxial tensile tests with different notch sizes are carried out, and the load -displacement curves of each specimen are obtained. The true stress-strain constitutive relation-ship of the weld zone material is obtained by the Bayesian regularization back propagation (BRBP) neural network and the Grey wolf optimizer (GWO). The accuracy of the constitutive relationship is fully verified by the test data, and the relative error is less than 1%. In addition, taking the weld material of the oil and gas pipeline as an example, this paper proposes a universal design method of specimen size with a notch, which is convenient for researchers in different fields to measure the stress-strain constitutive relationship of different materials. The proposed inversion method can provide an accurate stress-strain constitutive relationship for the safety evaluation of girth welds of high-grade pipelines.

关键词： Notched bar test Stress -strain constitutive relationship BRBP neural network GWO algorithm optimization inversion

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optimization inversion of Contaminant Transport Model Parameters in Unsaturated Soil

Optimization Inversion of Contaminant Transport Model Parame...

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第十届全国渗流力学学术会议暨2009渗流力学及应用国际论坛

作者： LIANG Bing~2,ZHAO Ying~(1,2),XUE Qiang~1 1.Department of Mechanics and Engineering Sciences,Liaoning Technical University,Fuxin 123000, China 2.State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China

Parameter estimation is the key job of mathematics simulation and *** on the seepage mechanics of unsaturated soil and the theory of solute transport,the contaminant transport model considering adsorption,desorption and immobile water in one-dimension was established,and was taking as the awaiting inversion *** least-squares technique was used to establishing objective function,and the Newton method was used to calculate iterative problem of the model *** checking the optimization inversion method of model parameters,the laboratory experiment was done for obtaining experimental values of contaminant *** comparison curves showed that the breakthrough curves calculated by using the inversion parameters are in good agreement with the data derived from laboratory *** indicates that optimization inversion method in this paper is feasible,and the forecast result is dependable.

关键词： contaminant transport model parameters optimization inversion least square method Newton iteration method

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Boundary Condition Updating of Bridge Structure Based on Mode Parameters

Boundary Condition Updating of Bridge Structure Based on Mod...

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International Conference on Structures and Building Materials

作者： Shi, Zhou Zhao, Renda Qin, Shiqiang Gao, Yufeng SW Jiaotong Univ Sch Civil Engn Chengdu 610031 Peoples R China

ISBN: (纸本)9780878492060

According to the complex boundary condition of real bridge structure, appendix restraint parameters of structure boundary condition were detailed analyzed. The appendix horizontal and torsional restraint parameters were selected as research object. The least square constrained optimization inversion method was used to establish the question of reverse of bridge structure boundary appendix parameters based on tested and calculated mode parameters. The first order perturbation of eigen-value and eigen-vector based on matrix perturbation theory were substituted into the constrained optimization inversion equation, so the solving efficiency was improved greatly, and the iteration method was used to improve the precision. The corresponding program was made, and the example of a maglev railway girder shows that fairly well precise bridge structure boundary appendix parameters can be reserved with only former several modes parameters through four to seven times of iteration calculation.

关键词： Model Updating Boundary Condition Mode Parameters optimization inversion

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