Compatibility Check for Flight Test Data from Aircraft Based on Maximum Likelihood Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.602-605.3202 ◽

2014 ◽

Vol 602-605 ◽

pp. 3202-3205

Author(s):

Xu Sheng Gan ◽

Xue Qin Tang ◽

Hai Long Gao

Keyword(s):

Maximum Likelihood ◽

Test Data ◽

Nonlinear Model ◽

Maximum Likelihood Method ◽

Flight Test ◽

Likelihood Method

To accurately identify the nonlinear model for aircraft, maximum likelihood method is introduced to analyze the flight test data for compatibility check, which can satisfy the kinematics equations of aircraft at the same time. The experiment shows that the proposed method has a good compatibility check effect, and it is also effective and feasible for flight test data for aircraft.

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A Method to Evaluate the Temper Embrittlement from Step Cooling Test

Materials Science Forum ◽

10.4028/www.scientific.net/msf.850.457 ◽

2016 ◽

Vol 850 ◽

pp. 457-465

Author(s):

Han Kui Wang ◽

Tong Xu ◽

Bin An Shou

Keyword(s):

Transition Temperature ◽

Maximum Likelihood ◽

Nonlinear Model ◽

Maximum Likelihood Method ◽

Temper Embrittlement ◽

Likelihood Method ◽

Weight Factor ◽

Test Results ◽

Molybdenum Steel

A new mathematic approach was proposed to evaluate the temper embrittlement from the step cooling test. The approach was composed of two parts. A nonlinear model, which acted as weight factor, was used to fit the variance at different test temperatures, and the maximum likelihood method was used to determine the curve parameters. In the ASME specification SA-542, there was no instruction to be provided on how to determine the transition temperature from the test results. This method is adopted as an additional supplementary requirement to assess the temper embrittlement of Chromium-Molybdenum steel.

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Statistical evaluation of fatigue tests using maximum likelihood

Materials Testing ◽

10.1515/mt-2020-0116 ◽

2021 ◽

Vol 63 (8) ◽

pp. 714-720

Author(s):

Klaus Störzel ◽

Jörg Baumgartner

Keyword(s):

Maximum Likelihood ◽

Normal Distribution ◽

Test Data ◽

Maximum Likelihood Method ◽

Statistical Evaluation ◽

Test Procedure ◽

Fatigue Tests ◽

Likelihood Method ◽

Parameter Determination ◽

Number Of Cycles

Abstract The statistical evaluation of fatigue tests can be carried out using the maximum likelihood method. With this method, the influence of run-outs on the S-N curve can be statistically considered. Typically, a bilinear S-N curve (Wöhler curve) in double-logarithmic representation is used. The logarithmic normal distribution is the basis for describing the scatter, which is assumed here to be independent of the number of cycles. For parameter determination via the maximum likelihood method, reliability is examined and compared with the evaluation methods proposed in DIN 50100. While a defined test procedure is required for the application of DIN 50100, any test data can be evaluated according to the maximum likelihood method. In comparison with the methods proposed in DIN 50100, it could be shown through some examples that the maximum likelihood method yields very reliable results for all S-N curve parameters.

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A Method to Evaluate the Temper Embrittlement From Step Cooling Test

ASME 2014 Symposium on Elevated Temperature Application of Materials for Fossil, Nuclear, and Petrochemical Industries ◽

10.1115/etam2014-1015 ◽

2014 ◽

Author(s):

Wang Hankui ◽

Xu Tong ◽

Shou Binan

Keyword(s):

Transition Temperature ◽

Maximum Likelihood ◽

Nonlinear Model ◽

Maximum Likelihood Method ◽

Temper Embrittlement ◽

Likelihood Method ◽

Weight Factor ◽

Test Results ◽

Molybdenum Steel

A new mathematic approach is proposed to evaluate the temper embrittlement from the step cooling test. The approach is composed of two parts. A nonlinear model, which acts as weight factor, is used to fit the variance at different test temperatures, and the maximum likelihood method is used to determine the curve parameters. In the ASME specification SA-542, there is no instruction provided on how to determine the transition temperature from the test results. This method could be adopted as an additional supplementary requirement to assess the temper embrittlement of Chromium-Molybdenum steel. Paper published with permission.

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Parameter Identification of Tailplane Iced Aircraft Based on Maximum Likelihood Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.192.57 ◽

2012 ◽

Vol 192 ◽

pp. 57-62 ◽

Cited By ~ 2

Author(s):

Zhong Da Xu ◽

Yi Hua Cao ◽

Ming Zhao

Keyword(s):

Maximum Likelihood ◽

Parameter Identification ◽

Maximum Likelihood Method ◽

Flight Test ◽

Likelihood Method ◽

Identification System ◽

Flight Performance ◽

Aerodynamic Parameters ◽

Flight Dynamics Model ◽

Ice Shapes

Based on the maximum likelihood method, this paper analyzed the influence of tailplane icing on aerodynamic parameters by parameter identification. A nonlinear longitudinal flight dynamics model for aircraft was built, and an identification system was constructed using maximum likelihood method. According to the flight test data of DHC-6 aircraft, the aerodynamic parameters of clean aircraft and two different cases of iced aircraft with particular ice shapes on the tailplane were identified. Eventually, the results of the identification show that the tailplane icing has several adverse effects on the aircraft flight characteristics, including flight performance, elevator effectiveness, stability and safety.

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