Real Time Estimation of Modal Parameters and Their Quality Assessment

In this paper the recursive method for modal parameters estimation is formulated and verified. Formulated algorithms are implemented in the FPGA electronic chip. As a result, the modal parameters and confidence bounds for the modal parameters are obtained in real time. The algorithms and their implementations are tested on laboratory test rig data and applied to – flight modal analysis of an airframe structure.

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A Bayesian-Probabilistic Framework for Real-Time Fatigue Usage Factor Monitoring of Nuclear Reactor Components

Volume 1A: Codes and Standards ◽

10.1115/pvp2015-45848 ◽

2015 ◽

Author(s):

Subhasish Mohanty ◽

William Iverson ◽

William K. Soppet ◽

Saurindranath Majumdar ◽

Krishnamurti Natesan

Keyword(s):

Real Time ◽

Nuclear Reactor ◽

Structural Integrity ◽

Research Work ◽

Time Estimation ◽

Basic Research ◽

Probabilistic Framework ◽

Confidence Bounds ◽

Pressurized Water ◽

Real Time Estimation

Real-time estimation of the fatigue usage factor of nuclear reactor components are helpful tools for on-demand assessment of component structural integrity. Real-time measurements of field variables, such as stress and strain, along with the use of historic/available stress/strain versus fatigue life data and a Bayesian-probabilistic framework can not only help to estimate the fatigue usage factor of reactor components in real time but also can help to estimate the associated confidence bounds. In this paper, a Gaussian Process based Bayesian-probabilistic framework is proposed for real-time estimation of mean fatigue usages factor and associated probabilistic bounds. The preliminary proof of concept was demonstrated through fatigue experiments with 316 stainless steel specimens under different conditions: a) under 300 °C and pressurized water reactor (PWR) water chemistry, and b) room temperature and in-air condition. At present the proposed probabilistic monitoring approach is not part of any code requirements, however the proposed framework is output of a futuristic basic research work, which requires more advancement. Also the results discussed in the paper are part of very preliminary basic research and requires advance validation such as under realistic nuclear reactor conditions.

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A machine for real-time estimation of the tribological characteristics of materials

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2020-86-4-61-65 ◽

2020 ◽

Vol 86 (4) ◽

pp. 61-65

Author(s):

M. V. Abramchuk ◽

R. V. Pechenko ◽

K. A. Nuzhdin ◽

V. M. Musalimov

Keyword(s):

Real Time ◽

Time Estimation ◽

Tribological Characteristics ◽

Continuous Processing ◽

Friction Machine ◽

Dynamic Friction Coefficient ◽

Displacement Sensors ◽

Frictional Interaction ◽

Real Time Estimation ◽

Automated Quality Control

A reciprocating friction machine Tribal-T intended for automated quality control of the rubbing surfaces of tribopairs is described. The distinctive feature of the machine consists in implementation of the forced relative motion due to the frictional interaction of the rubbing surfaces fixed on the drive and conjugate platforms. Continuous processing of the signals from displacement sensors is carried out under conditions of continuous recording of mutual displacements of loaded tribopairs using classical approaches of the theory of automatic control to identify the tribological characteristics. The machine provides consistent visual real time monitoring of the parameters. The MATLAB based computer technologies are actively used in data processing. The calculated tribological characteristics of materials, i.e., the dynamic friction coefficient, damping coefficient and measure of the surface roughness, are presented. The tests revealed that a Tribal-T reciprocating friction machine is effective for real-time study of the aforementioned tribological characteristics of materials and can be used for monitoring of the condition of tribo-nodes of machines and mechanisms.

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