Research on the Inverse Identification Method of Stiffness Parameters Based on A Single Test

Author:Gu Xue Sen

Supervisor:fu shan

Database:Doctor

Degree Year:2017

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Pages:164

Size:6545K

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The traditional measurement method of material stiffness parameters needs to carry out a series of standard tests,costing lots of materials and time.In order to improve the efficiency of stiffness identification and reduce the cost of tests,the inverse identification method of stiffness parameters based on a single test was investigated in this paper.By optimizing the test configuration,all the stiffness parameters can be identified simultaneously with a single specimen and a single loading.The focus of this study lies in the combination of full field strain measurement technique and global optimization algorithm,together with the evaluation and improvement of the inverse identification method.The increase of test efficiency,the reduction of test cost and the accuracy of identification were guaranteed by using the optimized test configuration and processing parameters.The main contents and innovations of this study include:1 Construct an inverse identification system of stiffness parameters based on a single testBy combining the full field measurement technique and inverse identification method,a stiffness identification system based on a single test was constructed in this study.All the stiffness parameters can be identified using a single specimen and a single loading.Compared to the traditional way of carrying out several standard tests,this method improves the test efficiency and reduces the cost.2 Propose methods of simulation,evaluation and optimization of inverse identification system based on a single testA numerical simulation method of the whole inverse identification chain of stiffness parameters was proposed,using techniques of finite element modeling and speckle deformation processing.The total identification error was considered as the performance index of the stiffness identification system.In order to improve the system performance,a global optimization method was applied.By decomposing the main steps in the simulation system into a series of key control parameters,the optimization of the whole process can be achieved and the errors introduced in each step can be analyzed.The influence degree of each parameter in the identification result was studied qualitatively,and the optimal value of each parameter in the given test configuration was solved quantitatively.3 Propose an experimental verification method of the optimization of inverse identification system of stiffness parameters based on a single testIn order to verify the optimal test configuration,the reference stiffness values were acquired by applying standard tests and input into the inverse identification simulation system to calculate the simulated stiffness results.Then the experimental stiffness results were obtained by carrying out real tests with optimized configurations.By comparing the full field strain information and the identification results of stiffness parameters calculated by different methods,the simulation system was proved to simulate the experimental results well and the optimal test configuration had a better identification results,which verified the optimization method.The methods of simulation,evaluation and optimization of the inverse identification system can be used to further optimize the stiffness parameters identification test.