scholarly journals Damage Localization of an Offshore Platform considering Temperature Variations

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Shuqing Wang ◽  
Min Zhang ◽  
Huajun Li
Keyword(s):  
Temperature Variation ◽  
Numerical Study ◽  
Offshore Platform ◽  
Structural Safety ◽  
Effect Of Temperature ◽  
Modal Parameters ◽  
Damage Localization ◽  
Offshore Structure ◽  
Modal Strain Energy ◽  
Temperature Variations

Modal parameters are sensitive indicators of structural damages. However, these modal parameters are sensitive not only to damage, but also to the environmental variations. Development of vibration based damage detection methodology which is robust to environmental variation is essentially important for the structural safety. The present paper utilizes a recently developed modal strain energy decomposition (MSED) method to localize the damage of an offshore structure. A progress of the present paper is to take the temperature variation into consideration and Monte Carlo simulation is introduced to investigate the effect of temperature variation on the robustness of damage localization. Numerical study is conducted on an offshore platform structure considering the temperature variation. Several damage cases, including single and double damage scenarios, are included to investigate the damage localization algorithm. Results indicate that the MSED algorithm is able to detect the damage despite the temperature variations.

Cross Modal Strain Energy Method for Damage Detection Using Limited Modal Data

2013 ◽  
Vol 284-287 ◽  
pp. 1285-1289 ◽  
Author(s):  
Shu Qing Wang ◽  
Min Zhang ◽  
Fu Shun Liu
Keyword(s):  
Iterative Process ◽  
Strain Energy ◽  
Numerical Study ◽  
Damage Localization ◽  
Modal Strain Energy ◽  
Modal Data ◽  
Severity Estimation ◽  
Modal Strain Energy Method ◽  
Numerical Result ◽  
Strain Energy Method

This paper extends the recently developed cross modal strain energy (CMSE) method for damage localization and severity estimation, using limited modal data, with iterative process. For investigating the performance and verifying the effectiveness of the present CMSE method, the numerical study of this article chooses a damaged beam that was investigated in a published article. The numerical result indicates that the CMSE method is capable of detecting the damage locations and estimating their severities properly, even when only few spatially incomplete, noisy modes are utilized.

Mode Selection for Offshore Platform Damage Identification Using CMSE Sensitivity

2019 ◽  
Author(s):  
Mingqiang Xu ◽  
Yuchi Liu ◽  
Yufeng Jiang ◽  
Shuqing Wang
Keyword(s):  
Structural Damage ◽  
Strain Energy ◽  
Damage Identification ◽  
Numerical Study ◽  
Mode Selection ◽  
Offshore Platform ◽  
Selection Strategy ◽  
Sensitivity Index ◽  
Modal Strain Energy ◽  
The Cross

Abstract A sensitivity-based mode selection strategy for cross modal strain energy (CMSE) method is proposed to identify damage more effectively. The cross modal strain energy sensitivity is defined as the sensitivity index. For this purpose, the cross modal strain energy sensitivity to structural damage is deduced, and is used to select the preferable mode combinations that are sensitive to damage. By using the preferable mode combinations, the CMSE system is refined and the degree of ill-posedness of the CMSE system is reduced. A numerical study is conducted on an offshore platform structure to demonstrate the effectiveness of the proposed scheme. The performances of the CMSE method with and without using the mode selection strategy are compared in the presence of noise. Results show that: (1) the accuracy of damage localization is improved when only a few mode combinations are utilized; (2) On account of excluding substantial low-sensitivity mode combinations, the amount of computation is significantly reduced.

scholarly journals Effect of Temperature Variation of Static Thermal Tensioning on Angular Distortion and Sensitization behavior of GMAW Welded SUS 304 Stainless Steel Plate

2021 ◽  
Vol 21 (3) ◽  
pp. 218-224
Author(s):  
R.N. Akhsanu Takwim ◽  
◽  
Purwoko Purwoko ◽  
Bayu Pranoto ◽  
◽  
...  
Keyword(s):  
Temperature Variation ◽  
304 Stainless Steel ◽  
Angular Distortion ◽  
Effect Of Temperature ◽  
Electric Heater ◽  
Welding Parameters ◽  
Back Side ◽  
Temperature Variations ◽  
Thermal Tensioning ◽  
Gmaw Welding

Due to its rust resistance properties, the use of stainless steels, especially SUS304 for industrial equipment is increasing. The manufacturing process that is often used is GMAW welding. One of the disadvantages of SUS304 is the occurrence of distortion and sensitization when welded. In this study, the effect of temperature variations of Static Thermal Tensioning on angle distortion and microstructure behavior due to GMAW welding of SUS 304 T-joint plates was studied. Heating by electric heater is given to both parts of the base metal plate SUS 304 5mm thick with temperature variations of 200 oC, 250 oC and 300 oC. Cooling water with a temperature of 24 oC is provided on the back side of the welded track. Welding using filler ER 304 with a diameter of 0.8 mm with welding parameters such as welding current, voltage, gas flow and travel speed controlled at 75 A, 22 V, 10 l/min and 8 mm/s, respectively. Angular distortion of welding results for each treatment temperature variation was measured using a bevel protractor, and perform metallographic test to knowing the microstructural behavior. The results of the measurement of the average angular distortion of three repetitions show that at a temperature of 250 C static thermal tensioning produces the smallest angular distortion of 3ᵒ70', compared to other temperature variations which produce angular distortion 4o45’ at 200 oC and 3o86' at temperature 300 oC. The findings of the largest Cr (carbide) deposits due to sensitization were found at a temperature of 300 oC at 16,49% and the lowest at a temperature of 200 oC at 7,05%

Cross Modal Strain Energy Method for Damage Localization and Severity Estimation

2007 ◽  
Author(s):  
Shuqing Wang ◽  
Huajun Li ◽  
Sau-Lon James Hu
Keyword(s):  
Strain Energy ◽  
Numerical Study ◽  
Element Model ◽  
Damage Localization ◽  
Modal Strain Energy ◽  
Damage Diagnosis ◽  
Damage Scenarios ◽  
Severity Estimation ◽  
Modal Strain Energy Method ◽  
Diagnosis Method

A cross modal strain energy (CMSE) damage diagnosis method, which is capable of localizing the damages and estimating their severities, is presented. The numerical study uses measurements synthesized from a finite element model of a laboratory-scaled offshore platform. Several damage scenarios are investigated, including: single/double damaged element(s), with/without measurement noise. Numerical results suggest that good performance on both damage location and severity assessment can be achieved by implementing the CMSE method.

Structural Damage Localization Using D-S Evidence Theory

2011 ◽  
Vol 105-107 ◽  
pp. 999-1003 ◽  
Author(s):  
Jian Hua Zhao ◽  
Ling Zhang
Keyword(s):  
Structural Damage ◽  
Damage Identification ◽  
Numerical Study ◽  
Evidence Theory ◽  
Final Decision ◽  
Damage Localization ◽  
Damage Evaluation ◽  
Modal Strain Energy ◽  
Independent Information ◽  
Information Fusion Technique

Damage localization is a key issue in the Structural Health Monitoring (SHM). In order to enhance the accuracy of damage localization, an approach based on D-S evidence theory is studied in this paper. First, damage results obtained from the modal strain energy change ratio (MSECR) method and the multiple damage location assurance criterion (MDLAC) method are regarded as two independent information sources, respectively. And then, the D-S evidence theory-based information fusion technique is employed to integrate these two results and make a final decision. To compare the damage identification results under different methods, a practical damage evaluation indicator is presented. Numerical study on a cantilever beam is carried out to verify the proposed method. Results indicate that the damage evaluation indicators calculated by D-S evidence theory are superior to the single method. That is to say, structural damage identification method based on D-S evidence theory performs very well in determining the damage locations.

THE EFFECT OF TEMPERATURE VARIATION ON RESISTANCE VALUE IN ELECTRICITY CIRCUITS

2020 ◽  
Vol 4 (1) ◽  
pp. 27
Author(s):  
Ridwan Yusuf Lubis ◽  
Lailatul Husna Lubis ◽  
Miftahul Husnah
Keyword(s):  
Temperature Variation ◽  
Effect Of Temperature ◽  
Resistance Value

Exploring secondary interactions and the role of temperature in moisture-contaminated polymer networks through molecular simulations

Soft Matter ◽  
2021 ◽  
Vol 17 (10) ◽  
pp. 2942-2956
Author(s):  
Rishabh D. Guha ◽  
Ogheneovo Idolor ◽  
Katherine Berkowitz ◽  
Melissa Pasquinelli ◽  
Landon R. Grace
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Temperature Variation ◽  
Polymer Networks ◽  
Molecular Simulations ◽  
Effect Of Temperature ◽  
Secondary Interactions ◽  
Dynamics Simulations ◽  
Secondary Bonding

We investigated the effect of temperature variation on the secondary bonding interactions between absorbed moisture and epoxies with different morphologies using molecular dynamics simulations.

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