Ultimate Elastic Wall Stress (UEWS) Test under Biaxial Loading for Glass-Fibre Reinforced Epoxy (GRE) Pipes

2014 ◽  
Vol 974 ◽  
pp. 188-194 ◽  
Author(s):  
Tarak A. Assaleh ◽  
Lutfeya A. Almagguz
Keyword(s):  
Biaxial Loading ◽  
Pipe Wall ◽  
Axial Stress ◽  
Wall Stress ◽  
Current Method ◽  
Raw Material ◽  
Attractive Alternative ◽  
Filament Wound ◽  
Elastic Wall ◽  
Filament Wound Composite

This paper presents the results of an experimental investigation into the Ultimate Elastic Wall Stress (UEWS) of ±55° filament wound composite pipes. The UEWS test appears to provide an attractive alternative to the current method, and has proved to be one of the most effective in term of accuracy and speed. Moreover, it has been found to be sensitive to changes in key manufacturing and raw material parameters. The pipes were subjected to biaxial loading, which was achieved by combinations of hoop and axial stress. Loads were applied as groups of cycles which, were gradually increased until the UEWS had been determined. Various ratios of hoop to axial stress were applied to the pipes, ranging from pure axial to pure hoop loading at room temperature and at 65°C. These ratios were investigated by applying different pressures in both the main and small chambers built inside the pipe, and therefore it was unnecessary to add any external loads to the pipe wall. Tests were also conducted to observe leakage through the pipe wall. The main failure mode observed was weepage through the pipe wall, which was due to intensive matrix microcracking. The results from the UEWS tests are presented in the form of failure envelopes showing the effects of testing at an elevated temperature. Finally, degradation in the elastic properties of the pipe wall is also discussed and plotted against wall stress.

scholarly journals ALTERNATIVE METHOD FOR QUALIFICATIONS OF GLASS FIBRE REINFORCED EPOXY PIPES (GRE)

2019 ◽  
Vol 2 (2) ◽  
pp. 73-81
Author(s):  
Tarak Assaleh ◽  
Siddig Dabbashi ◽  
Asya A. Gabbasa
Keyword(s):  
Biaxial Loading ◽  
Axial Stress ◽  
Wall Stress ◽  
Raw Material ◽  
Attractive Alternative ◽  
Hydrostatic Loading ◽  
Biaxial Load ◽  
Pressure Tests ◽  
Glass Fibre Reinforced

This paper discusses the Ultimate Elastic Wall Stress (UEWS) test for GRE pipes under pure hydrostatic loading. UEWS appears to provide an attractive alternative to the currently used procedure laid down in ISO 14692, which involves an expensive series of long term constant pressure tests, as described in ASTM 2992, running for a period in excess of 10,000 hours. The pipes were subjected to biaxial loading, which was attained by combinations of hoop and axial stress. Loads were applied as groups of cycles which, were gradually increased until the UEWS had been determined. UEWS test has proved to be one of the most effective in terms of accuracy and speed. Moreover, it has been found to be sensitive to changes in key manufacturing and raw material parameters. Modelling results are also showed a harmonic approach and accepted to that obtained experimentally. This encourages to apply the proposed modelling for further biaxial load ratios.

Using MFL Corrosion Signals to Determine Biaxial Stress in Operating Pipelines

2000 ◽  
Author(s):  
Alfred E. Crouch
Keyword(s):  
Magnetic Flux ◽  
Internal Pressure ◽  
Pipe Wall ◽  
Axial Stress ◽  
Wall Stress ◽  
Biaxial Stress ◽  
Metal Loss ◽  
Pipe Surface ◽  
The Difference ◽  
Hoop Stresses

Previous work has shown that a corrosion assessment more accurate than B31.G or RSTRENG can be made if pipeline stresses are considered. A shell analysis can be carried out if both the corrosion profile and local pipe wall stresses are known. The corrosion profile can be approximated from analysis of magnetic flux leakage (MFL) signals acquired by an inline inspection tool (smart pig), but a measure of pipe wall stress has not been available. Approximations have been made based on pipe curvature, but a more direct measurement is desirable. Recent work has produced data that show a correlation between multi-level MFL signals from metal-loss defects and the stress in the pipe wall at the defect location. This paper presents the results of MFL scans of simulated corrosion defects in pipe specimens subjected to simultaneous internal pressure and four-point bending. MFL data were acquired at two different magnetic excitations using an internal scanner. The scanner’s sensor array measured axial, radial and circumferential magnetic flux components on the inner pipe surface adjacent to the defect. Comparison of the signals at high and low magnetization yields an estimate of the difference between axial and hoop stresses. If internal pressure is known, the hoop component can be determined, leaving data proportional to axial stress.

The strength of a filament wound composite under biaxial loading

Composites ◽  
1978 ◽  
Vol 9 (4) ◽  
pp. 247-250 ◽  
Author(s):  
P.D. Soden ◽  
D. Leadbetter ◽  
P.R. Griggs ◽  
G.C. Eckold
Keyword(s):  
Biaxial Loading ◽  
Filament Wound ◽  
Filament Wound Composite ◽  
Wound Composite

Modelling of Multi-Axial Ultimate Elastic Wall Stress (UEWS) Test for Glass Fibre Reinforced Epoxy (GRE) Composite Pipes

2013 ◽  
Vol 367 ◽  
pp. 113-117
Author(s):  
M.S. Abdul Majid ◽  
M. Afendi ◽  
R. Daud ◽  
N.A.M. Amin ◽  
A. Mohamad ◽  
...  
Keyword(s):  
Glass Fibre ◽  
Raw Materials ◽  
Wall Stress ◽  
Good Alternative ◽  
Matrix Cracking ◽  
Filament Wound ◽  
Elastic Wall ◽  
Glass Fibre Reinforced ◽  
Composite Pipes ◽  
Good Agreement

This paper describes the modeling of multiaxial ultimate elastic wall stress (UEWS) at room temperature for glass fibre reinforced epoxy (GRE) composite pipes. The model developed, predicts the stress-strain response caused by the combined, static and cyclic of UEWS loading taking into effects of transverse matrix cracking within the laminates. The procedure, although not a standard method, seems to provide a good alternative to the current raw materials' re-qualification procedure delineated in ISO 14692 through ASTM D2992. The effective transverse and shear modulus of the lamina due to increasing presence of transverse matrix cracking were estimated. Classical laminate analysis was then applied to compute the corresponding ply properties as a function of increasing stress and strain. The model shows a good agreement with the experimental results of multiaxial UEWS tests on ±55° filament wound glass-reinforced epoxy pipes.

Spring constants of filament-wound composite circular rings

2001 ◽  
Vol 215 (2) ◽  
pp. 211-226 ◽  
Author(s):  
P C Tse ◽  
S R Reid ◽  
S P Ng
Keyword(s):  
Three Dimensional ◽  
Element Analysis ◽  
Closed Form Solutions ◽  
Composite Ring ◽  
Filament Wound ◽  
Dimensional Finite Element ◽  
Filament Wound Composite ◽  
Circular Rings ◽  
Three Dimensional Finite Element ◽  
Wound Composite

Closed-form solutions from complementary strain energy are derived for the spring stiffnesses of mid-surface symmetric, filament-wound, composite circular rings under unidirectional loading. A three-dimensional finite element analysis (FEA) including the effects of transverse shear has also been applied to study the problem. Four > 45° and four > 75° E-glass/epoxy composite rings of odd numbers of covers were tested. Comparisons of the results obtained from the two methods with experimental data are made and the results are found to be in good agreement. The FEA prediction of stiffness is always higher than the theoretical result. The relationships between the spring stiffnesses and the winding angles and geometry of the filament-wound composite ring are considered and discussed.

Towards the Development of Filament Wound Composite Structures Submitted to Very High Internal Pressure, Based on Complex Geometry Shapes

2013 ◽  
Author(s):  
Erik Vargas Rojas ◽  
David Chapelle ◽  
Dominique Perreux
Keyword(s):  
Internal Pressure ◽  
Composite Structures ◽  
Complex Geometry ◽  
Industrial Applications ◽  
Filament Winding ◽  
Complex Geometries ◽  
Filament Wound ◽  
Complex Shapes ◽  
Filament Wound Composite ◽  
High Internal Pressure

Industrial applications, especially composite structures bearing high internal pressure, and fabricated using the filament winding process face certain difficulties like the reinforcement of complex shapes, as well as the correct placement of fibers over the surface of a mandrel. In some cases the definition of the manufacturing parameters respond more to cost or time criteria rather than engineering standards, reducing largely the advantages of the said manufacturing process. In order to overcome these obstacles, this research aims to propose a solution that permits to fabricate complex shapes with the desired winding angles at a certain region of complex-shaped mandrels. A numerical tool that simulates the placement of fiber tows over the surface of complex geometries is developed and validated by means of the fabrication of convex and concave composite structures using detachable mandrels. Previous results show that it is feasible to wind complex geometries with good accuracy.

Environmental effects on the durability of filament wound composite structures

1996 ◽  
Author(s):  
J. Wlodarski ◽  
Charles Pergantis ◽  
Thomas Mulkern ◽  
James Kleinmeyer
Keyword(s):  
Environmental Effects ◽  
Composite Structures ◽  
Filament Wound ◽  
Filament Wound Composite ◽  
Wound Composite

scholarly journals Drying of suspension and pastes in fluidized bed of inert particles

2000 ◽  
Vol 65 (12) ◽  
pp. 963-974 ◽  
Author(s):  
Zeljko Grbavcic ◽  
Zorana Arsenijevic ◽  
Radmila Garic-Grulovic
Keyword(s):  
Pure Water ◽  
Operating Conditions ◽  
Raw Material ◽  
Water Evaporation ◽  
Large Temperature ◽  
Attractive Alternative ◽  
Mechanical Agitation ◽  
Inert Particles ◽  
Fluid Bed ◽  
Drying Efficiency

A fluid bed dryer with inert particles was used for the drying of suspensions and pastes. The effects of the operating conditions on the dryer throughput and on the product quality were investigated. Experiments were performed in a cylindrical column 215 mm in diameter and 1200 mm in height with 0.925 mm diameter glass spheres as the fluidizing media. Cineb fungicide, copper hydroxide and pure water were used as the feed material. With respect to the main efficiency criteria, i.e., specific water evaporation rate, specific heat consumption and specific air consumption, a fluid bed dryer with inert particles represents a very attractive alternative to other drying technologies. A high drying efficiency results from the large contact area and from the large temperature difference between the inlet and outlet air. A rapid mixing of the particles, due to aggregative fluidization and mechanical agitation, leads to nearly isothermal conditions throughout the bed. In our experiments, suspensions and very dense pastes were successfully treated. Suspension and product hold-up in the bed varies between 6 and 8 % by mass and a product with the same particle size as the raw material is obtained.

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