公开(公告)号：US20220260468A1

公开(公告)日：2022-08-18

申请号：US17733853

申请日：2022-04-29

申请人： NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS

发明人： Yingdong SONG ,  Xu ZHAO ,  Zhigang SUN ,  Xuming NIU ,  Yaning CHANG ,  Qiuhong PENG

IPC分类号： G01N3/18

摘要： Disclosed is a method for compiling an equivalent acceleration spectrum of creep under variable temperatures and loads. The method includes following steps: respectively carrying out a material high-temperature tensile test, material high-temperature creep tests and creep tests under two-stage variable temperatures and loads, and calculating values of a parameter p in a creep damage accumulation model under two-stage variable temperatures and loads; based on a nonlinear damage accumulation model under multi-stage variable temperatures and loads, calculating a damage D caused by a multi-stage variable temperatures and loads creep load spectrum by utilizing values of parameter p; based on the principle of consistency of damage D, transforming the multi-stage variable temperatures and loads creep load spectrum into an equivalent acceleration spectrum of a first-order maximum creep load, and finally compiling the equivalent acceleration spectrum of creep under variable temperatures and loads.

公开(公告)号：US20230184648A1

公开(公告)日：2023-06-15

申请号：US18094659

申请日：2023-01-09

申请人： NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS

发明人： Yingdong SONG ,  Xu ZHAO ,  Zhigang SUN ,  Xuming NIU

IPC分类号： G01N3/08 ,  G01N3/02

CPC分类号： G01N3/08 ,  G01N3/02 ,  G01N2203/0071 ,  G01N2203/0226 ,  G01N2203/0218 ,  G01N2203/0017

摘要： Disclosed is a method for predicting creep damage and deformation evolution behavior with time, which comprises the following steps: obtaining tensile strength σb through high-temperature tensile test; obtaining the strain curve, minimum creep rate {dot over (ε)}m and life tƒ through creep test; obtaining the threshold stress σth at different temperatures; establishing the relationship between the tensile strength σb, the threshold stress σth and the temperature T; establishing the prediction formulas of the minimum creep rate σth and creep life σb based on the threshold stress {dot over (ε)}m and the tensile strength tƒ; establishing a creep damage constitutive model, including strain rate formula and damage rate formula; obtaining the evolution behavior of strain and deformation with time; obtaining the evolution behavior of damage with time.

公开(公告)号：US20220268677A1

公开(公告)日：2022-08-25

申请号：US17743369

申请日：2022-05-12

申请人： NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS

发明人： Zhigang SUN ,  Xu ZHAO ,  Yingdong SONG ,  Xuming NIU ,  Yaning CHANG ,  Qiuhong PENG

IPC分类号： G01N3/18 ,  G01N3/02

摘要： Disclosed is an equivalent acceleration method of creep loads based on a consistent failure mode. The equivalent acceleration method includes obtaining corresponding tensile strengths; obtaining corresponding creep rupture time; establishing rupture time law, minimum creep rate law and rupture strain law; calculating the value of parameter p in creep damage accumulation model; and dividing the failure mode consistency interval of creep load under variable temperature and variable load. The damage caused by the creep load in the failure mode consistency interval is calculated by using the multi-grade variable temperature and variable load creep nonlinear damage accumulation model, the damage is accelerated to the maximum creep load state in the failure mode consistency interval according to the principle of damage equivalence, and finally the equivalent acceleration of creep load is realized.