Spacecraft Orbit an Composite Material Structure Design Oct. 2020-Dec. 2020
Supervisor: Prof. Li Mingtao
l Stuie the motion of spacecraft uner the impact of interior an exterior environments an control systems
l Complete the research an graspe the operation of the GMAT planetary orbit simulation software
l Wrote the paper to present the final result: iscusse the exploitation an utilization of celestial resources as well as iscusse a great eal of material science an material composition relate principles; conucte the eep analysis on the composition an existing substances after investigate the formation an evolution of planets an celestial boies; clarifie the specific research irection in the fiel of celestial resources evelopment an utilization, an also provie a basis for formulating a more accurate an efficient esign scheme for resource evelopment an utilization
Establishment of BP Neural Network Constitutive Moel for Ti-25Nb Alloy Sept. 2020-Oct. 2020
Supervisor: Prof. Wang Kelu
l Abstract: The isothermal constant strain rate compression test of the Ti-25Nb alloy in the temperature range of 470~620℃ an the strain rate range of 0.001~10 s-1 by a Gleeble3500 thermal simulation tester. It is to stuy the flow stress behavior an to establish a constitutive moel base on BP neural network. The results show that the true stress of Ti-25Nb alloy has negative temperature an positive strain rate sensibility. An the true stress-true stain curves’ characteristic is flow softening uner any eformation conition of Ti-25Nb alloy. The constitutive moel base on BP neural network has a high calculation accuracy, with correlation coefficient R of 0.9996, the relative error of 4.27%, an average absolute relative error AARE of 1.33%, which can well escribe an preict the flow stress behavior of Ti-25Nb alloy.
l Key Wors: Ti-25Nb alloy, Flow stress behavior, Constitutive moel, BP neural network
l Achievement: publishe this paper as the first author on Special Casting & Nonferrous Alloys, CN42-/1448TG, ISSN1001-2249
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