Some Properties of Acoustic Emission Signals Measured in the Vicinity of a Crack during the Cyclic Pressure Loading of a Vessel

1988 ◽  
pp. 2943-2950 ◽  
Author(s):  
B. Tirbonod ◽  
L. Hanacek
Keyword(s):  
Acoustic Emission ◽  
Pressure Loading ◽  
Cyclic Pressure

scholarly journals Simulation Study on the Potential of Braided Hose Failure in Internal Combustion Engines

2018 ◽  
Vol 225 ◽  
pp. 02017 ◽  
Author(s):  
S. Hassan ◽  
S. Afdhal ◽  
M. Shahrizal ◽  
A. Eleena
Keyword(s):  
Stress Distribution ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
The Other ◽  
Combustion Engines ◽  
Analysis Method ◽  
Pressure Loading ◽  
Working Pressure ◽  
Cyclic Pressure ◽  
Causes Of Failure

In this study, damaged braided hoses was obtained from the actual site to investigate the possible causes of failure in the internal combustion engines. The hoses were assembled with polytetrafluroethylene (PTFE) as the inner tube and externally braided outer tube corrosionresistant steel (CRES). The hose had undergone failures near the end of the fittings. The braided hose was measured and modelled using SOLIDWORKS CAD software. The ANSYS static structural stimulation was used to measure the stress distribution on the hose due to pressure applied with various bend shapes. The simulation was done by fixing the end of the pipe and exerting the working pressure inside the inner layer of PTFE. The results of the simulation have shown that the inner tube experienced high stresses near the fittings which is then aggravated with the bending. With cyclic pressure loading, the hose was unable to stand the high stresses near the fittings and therefore failed. Further analyses were done to the braided hose to investigate the other possible of failure using failure analysis method.

scholarly journals The durability test of tractor hydrostatic pump type UD 25 under operating load

2010 ◽  
Vol 56 (No. 3) ◽  
pp. 116-121 ◽  
Author(s):  
Š. Drabant ◽  
J. Kosiba ◽  
J. Jablonický ◽  
J. Tulík
Keyword(s):  
Vegetable Oil ◽  
Test Performance ◽  
Hydraulic Fluid ◽  
Fluid Temperature ◽  
Pressure Loading ◽  
Durability Test ◽  
Cyclic Pressure ◽  
Operating Load ◽  
Transmission Oil ◽  
Environmentally Responsible

The results of the UD 25 hydrostatic pump durability test are presented; they were obtained in the laboratory under operating load. The test of operating load was a continuation of the hydrostatic pump durability test with a cyclic pressure loading according to the norm STN 11 9287. It lasted 300 hours, with 70°C ± 2°C of hydraulic fluid temperature. The aim of the test was to simulate the operation of the hydrostatic pump under load in laboratory and to find out its deterioration and the influence of a biodegradable fluid on its qualities. The achieved results confirmed that flow efficiency of the UD 25 hydrostatic pump decreased only to 3.6% which points to its good technical state even after the test performance. Meanwhile we can state that the used ecological hydraulic fluid on the basis of a vegetable oil "Environmentally responsible tractor transmission oil", produced by the Slovnaft company, Inc., is characterised by very good qualities.

Acoustic emission of fatigue crack in pressure pipe under cyclic pressure

2010 ◽  
Vol 240 (10) ◽  
pp. 3616-3620 ◽  
Author(s):  
Qiong Ai ◽  
Cai-Xue Liu ◽  
Xiang-Rong Chen ◽  
Pan He ◽  
Yao Wang
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Cyclic Pressure ◽  
Pressure Pipe

Effect of Geometry, Material, and Pressure Variability on Strain and Stress Fields in Dented Pipelines Under Static and Cyclic Pressure Loading Using Probabilistic Analysis

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Husain M. Al-Muslim ◽  
Abul Fazal M. Arif
Keyword(s):  
Probabilistic Analysis ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Deterministic Model ◽  
Mechanical Damage ◽  
Statistical Distribution ◽  
Stress Fields ◽  
Pressure Loading ◽  
Cyclic Pressure ◽  
Pipe Geometry

Mechanical damage in transportation pipelines is a threat to their structural integrity. Failure in oil and gas pipelines is catastrophic as it leads to personal fatalities, injuries, property damage, loss of production, and environmental pollution. Therefore, this issue is of extreme importance to pipeline operators, government and regulatory agencies, and local communities. As mechanical damage can occur during the course of pipeline life due to many reasons, appropriate tools and procedures for assessment of severity is necessary. There are many parameters that affect the severity of the mechanical damage related to the pipe geometry and material properties, the defect geometry and boundary conditions, and the pipe state of strain and stress. The main objective of this paper is to investigate the effect of geometry, material, and pressure variability on strain and stress fields in dented pipelines under static and cyclic pressure loading using probabilistic analysis. Most of the published literature focuses on the strain at the maximum depth for evaluation, which is not always sufficient to evaluate the severity of a certain case. The validation and calibration of the base deterministic model was based on full-instrumented full-scale tests conducted by Pipeline Research Council International as part of their active program to fully characterize mechanical damage. A total of 100 cases randomly generated using Monte Carlo simulation are analyzed in the probabilistic model. The statistical distribution of output parameters and correlation between output and input variables is presented. Moreover, regression analysis is conducted to derive mathematical formulas of the output variables in terms of practically measured variables. The results can be used directly into strain based assessment. Moreover, they can be coupled with fracture mechanics to assess cracks for which the state of stress must be known in the location of crack tip, not necessarily found in the dent peak. Furthermore, probabilities derived from the statistical distribution can be used in risk assessment.

Effect of Geometry, Material and Pressure Variability on Strain and Stress Fields in Dented Pipelines Under Static and Cyclic Pressure Loading Using Probability Analysis

2010 ◽  
Author(s):  
Husain Mohammed Al-Muslim ◽  
Abul Fazal M. Arif
Keyword(s):  
Structural Integrity ◽  
Oil And Gas ◽  
Deterministic Model ◽  
Mechanical Damage ◽  
Statistical Distribution ◽  
Stress Fields ◽  
Pressure Loading ◽  
Cyclic Pressure ◽  
Mathematical Formulas ◽  
Pipe Geometry

Mechanical damage in transportation pipelines is a threat to its structural integrity. Failure in oil and gas pipelines is catastrophic as it leads to personal fatalities, injuries, property damage, loss of production and environmental pollution. Therefore, this issue is of extreme importance to Pipeline Operators, Government and Regulatory Agencies, and local Communities. As mechanical damage can occur during the course of pipeline life due to many reasons, appropriate tools and procedures for assessment of severity is necessary. There are many parameters that affect the severity of the mechanical damage related to the pipe geometry and material properties, the defect geometry and boundary conditions, and the pipe state of strain and stress. The main objective of this paper is to investigate the effect of geometry, material and pressure variability on strain and stress fields in dented pipelines under static and cyclic pressure loading using probabilistic analysis. Most of the published literate focuses on the strain at the maximum depth for evaluation which is not always sufficient to evaluate the severity of a certain case. The validation and calibration of the base deterministic model was based on full-instrumented full-scale tests conducted by Pipeline Research Council International as part of their active program to fully characterize mechanical damage. A total of 100 cases randomly generated using Monte Carlo simulations are analyzed in the probabilistic model. The statistical distribution of output parameters and correlation between output and input variables is presented. Moreover, regression analysis is conducted to derive mathematical formulas of the output variables in terms of practically measured variables. The results can be used directly into strain based design approach. Moreover, they can be coupled with fracture mechanics to assess cracks, for which the state of stress must be known in the location of crack tip, not necessarily found in the dent peak. Furthermore, probabilities derived from the statistical distribution can be used in risk assessment.

scholarly journals Effect of Autofrettage in the Thick-Walled Cylinder With a Radial Cross-Bore

2007 ◽  
Author(s):  
Hongjun Li ◽  
Richard Johnston ◽  
Donald Mackenzie
Keyword(s):  
Fatigue Life ◽  
Cyclic Load ◽  
Load Level ◽  
Pressure Loading ◽  
Optimum Pressure ◽  
Cyclic Pressure ◽  
Fatigue Data ◽  
Number Of Cycles ◽  
Walled Cylinder ◽  
Autofrettage Pressure

The effect of autofrettage on the stress level in thick-walled cylinders with a radial cross-bore is investigated by applying inelastic FEA with cyclic pressure loading. A macro is created in ANSYS to calculate the equivalent alternating stress intensity, Seq, based on the ASME Boiler and Pressure Vessel Code. The value of Seq is used to evaluate the fatigue life of the vessel. For a specific cyclic load level, a distinct optimum autofrettage pressure is identified by plotting autofrettage pressure against the number of cycles from design fatigue data. The fatigue life of the autofrettaged vessel with such an optimum pressure is significantly increased compared with the case where no autofrettage is used.

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