A method and equipment for the inspection of composite tubular specimen by thermography

2020 ◽  
Author(s):  
Dapeng Chen ◽  
Jian Zhou ◽  
Xiaoheng Wang ◽  
Yazhou Zhang
Keyword(s):  
Tubular Specimen

A Strain Based Criterion to Evaluate the Tensile Capacity of Transmission Pipelines Under Large Scale Cyclic Bending

2018 ◽  
Author(s):  
Y. Andrés Plata Uribe ◽  
Claudio Ruggieri
Keyword(s):  
Structural Steel ◽  
Large Scale ◽  
Axial Loading ◽  
Tensile Failure ◽  
Void Coalescence ◽  
Ductile Crack ◽  
Tubular Specimen ◽  
Pipe Surface ◽  
Cracking Behavior ◽  
Tension Tests

This study explores the capability of a computational cell methodology and a stress-modified, critical strain (SMCS) criterion for void coalescence implemented into a large scale, 3-D finite element framework to model ductile fracture behavior in tensile specimens and in damaged pipelines. In particular, the cell methodology provides a convenient approach for ductile crack extension suitable for large scale numerical analyses which includes a damage criterion and a microstructural length scale over which damage occurs. A series of tension tests conducted on notched tensile specimens with different notch radius for a carbon steel pipe provides the stress-strain response of the tested structural steel from which the cell parameters and the SMCS criterion are calibrated. To investigate ductile cracking behavior in damaged pipelines, full scale cyclic bend tests were performed on a 165 mm O.D tubular specimen with 11 mm wall thickness made of a pipeline steel with very similar mechanical characteristics to the structural steel employed in the tension tests. The tubular specimen was initially subjected to indentation by 3-point bend loading followed by a compressive axial loading to generate large localized buckling in the dented region. The axial loading was then reversed to a tension loading applied until a visible ductile crack could be observed in the pipe surface. These exploratory analyses predict the tensile failure load for the pipe specimen associated with ductile crack initiation in the highly damaged area inside the denting and buckling zone which is in good agreement with experimental measurements.

Burst Tests on Pipeline Containing Circumferential Corrosion Defects

2010 ◽  
Author(s):  
Adilson C. Benjamin ◽  
Jose´ Luiz F. Freire ◽  
Ronaldo D. Vieira ◽  
Jorge L. C. Diniz
Keyword(s):  
Internal Pressure ◽  
Material Properties ◽  
Impact Test ◽  
Tubular Specimen ◽  
Spark Erosion ◽  
X80 Steel ◽  
Corrosion Defects ◽  
Circumferential Defects ◽  
Tubular Specimens ◽  
Outside Diameter

Circumferential defects are the ones in which the width w is greater than the length L (w > L). In this paper the burst tests of three tubular specimens are presented. In these tests the tubular specimens were loaded with internal pressure only. The specimens were cut from longitudinal welded tubes made of API 5L X80 steel with a nominal outside diameter of 457.2 mm (18 in) and a nominal wall thickness of 7.93 mm (0.312 in). Each of the three specimens had one external circumferential corrosion defect, machined using spark erosion. Measurements were carried out in order to determine the actual dimensions of each tubular specimen and its respective defect. Tensile specimens and impact test specimens were tested to determine material properties. The failure pressures measured in the burst tests are compared with those predicted by five assessments methods, namely: the ASME B31G method, the RSTRENG 085dL method, the DNV RP-F101 method for single defects (Part B), the RPA method and the Kastner equation.

Inertia-induced radial confinement in an elastic tubular specimen subjected to axial strain acceleration

2010 ◽  
Vol 37 (4) ◽  
pp. 459-464 ◽  
Author(s):  
M. Zhang ◽  
Q.M. Li ◽  
F.L. Huang ◽  
H.J. Wu ◽  
Y.B. Lu
Keyword(s):  
Axial Strain ◽  
Tubular Specimen

The Effect of the State of Stress on the Strain at Fracture

1974 ◽  
Vol 96 (3) ◽  
pp. 190-194
Author(s):  
E. A. Davis
Keyword(s):  
Hydrostatic Pressure ◽  
Internal Pressure ◽  
The State ◽  
Tubular Specimen ◽  
State Of Stress ◽  
Tension Tests ◽  
Pressure Tests

Tension tests on solid cylindrical specimens and internal pressure tests on one type of tubular specimen showed that a superimposed hydrostatic pressure increased the ductility. Internal pressure tests on a similar tubular specimen that was supported in a different manner showed that the hydrostatic pressure had almost no effect on the ductility.

scholarly journals Experimental and Numerical Evaluation on Deformation and Fracture Mechanism of Cast Duplex Stainless Steel Tubular Specimen

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3430
Author(s):  
Zhenhua Li ◽  
Xinyu Wang ◽  
Tao Chen ◽  
Fan Feng ◽  
Pan Liu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Fracture Mechanism ◽  
Main Crack ◽  
Numerical Evaluation ◽  
Axial Stress ◽  
Internal Wall ◽  
Tubular Specimen ◽  
External Wall ◽  
Shear Lip

The deformation behavior and fracture mechanism of cast duplex stainless steel tubular specimens under different tensile stages were investigated through experimental and numerical evaluation. The results showed that the axial stress was redistributed due to the necking of the tubular specimen, the axial stress near the internal wall was larger than those near the external wall, and its maximum axial stress was distributed between the internal wall and the center of the wall thickness. Microcracks and voids were initiated under the maximum shear stress along the δ/γ phase interface and propagated to the ferrite interior. The voids were connected and merged into the main crack through the propagation of the microcracks. Moreover, the main crack first propagated to the internal wall and then rapidly propagated to the external wall. The fracture morphology can be divided into three types: shear lip zones that can be found on both the internal and external walls, and shear lip zones that can be found on either only the internal wall or the external wall.

A Thermomechanical PWR Test Facility to Investigate Thermal Shock Loading on a Small Scale Tubular Specimen

2018 ◽  
Author(s):  
Peter Gill ◽  
Norman Platts ◽  
Chris Currie ◽  
Eleanor Grieveson
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Thermal Shock ◽  
Life Prediction ◽  
Annular Flow ◽  
Shock Loading ◽  
Thermal Strain ◽  
Test Facility ◽  
Tubular Specimen ◽  
The Heat Transfer Coefficient

Pressurized water reactor environments are known to reduce the fatigue life of austenitic stainless steel components when compared to air environments. Laboratory testing has provided a means of quantifying this, allowing conservative plant assessments to be made. The majority of this testing has been isothermal and carried out on membrane loaded hollow or solid specimens. The geometry and loading of laboratory test specimens is significantly different to that experienced on plant, where complex strain waveforms are generally out of phase with temperature changes, and significant through wall strain gradients may be present. To address the issue of realistic loading, a test facility has been developed which can simulate thermal shock loading on a tubular specimen. The capability of the test facility was presented at the PVP2016 conference [PVP2016-63161]. Since then the facility has evolved, with modifications made to the rig configuration and specimen geometry in order to maximize the strain amplitude from the thermal shock, including the adoption of an annular flow geometry. These modifications were designed to optimize both the heat transfer coefficient and the speed of cycling between hot and cold water in order to induce a thermal strain that can cause mechanical failure within practicable test durations. In order to calculate the magnitude of the thermal strain, detailed calculations were required both in terms of thermal hydraulics as well as stress analyses. The latest stress analysis has been combined with state of the art life prediction models to estimate the time for crack initiation. This paper presents the results of the latest stress analysis and life prediction, including the derivation of the heat transfer coefficient for an annular flow region. The life prediction method uses best estimate strain-temperature histories from elastic-plastic finite element analysis (FEA). Heat-specific material properties have been developed during accompanying tests within the same experimental programme, and have been applied to enable cyclic hardening to be taken into account. The comparison of the prediction to an on-going test is also discussed.

Burst Tests on Pipeline Containing Interacting Corrosion Defects

2005 ◽  
Author(s):  
Adilson C. Benjamin ◽  
Jose Luiz F. Freire ◽  
Ronaldo D. Vieira ◽  
Jorge L. C. Diniz ◽  
Edmundo Q. de Andrade
Keyword(s):  
Material Properties ◽  
Laboratory Tests ◽  
Impact Test ◽  
Effective Area ◽  
Tubular Specimen ◽  
Spark Erosion ◽  
X80 Steel ◽  
Corrosion Defects ◽  
Tubular Specimens ◽  
Outside Diameter

In this paper the burst tests of seven tubular specimens are presented. In these tests the tubular specimens were loaded with internal pressure only. The specimens were cut from longitudinal welded tubes made of API 5L X80 steel with a nominal outside diameter of 457.2 mm (18 in) and a nominal wall thickness of 7.93 mm (0.312 in). The specimen IDTS 1 is a defect-free pipe. The specimen IDTS 2 contains only one defect, herein called base defect. The base defect is an external flat bottomed defect with uniform width (circumferential dimension). The other five specimens contain groups of interacting defects constituted by the combination of two or more base defects. All the defects were machined using spark erosion. Measurements were carried out in order to determine the actual dimensions of each tubular specimen and its respective groups of defects. Tensile specimens and impact test specimens were tested to determine material properties. The failure pressures measured in the laboratory tests are compared with those predicted by six assessments methods, namely: the ASME B31G method, the RSTRENG 085dL method, the DNV RP-F101 method for single defects, the RPA method, the RSTRENG Effective Area method and the DNV RP-F101 method for interacting defects.

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