Flaw Testing of Fiber Reinforced Composite Pressure Vessels

Author(s):  
John Makinson ◽  
Norman L. Newhouse

The ASME BPV Project Team on Hydrogen Tanks, in conjunction with other ASME Codes and Standards groups, is developing Code Cases and revisions to the Boiler & Pressure Vessel Code, including such to address the design of composite pressure vessels. The Project Team had an interest in further understanding the effect of cuts to the surface of composite tanks, and how the burst pressure would be affected during the lifetime of the pressure vessel. A test program was initiated to provide data on initial burst pressure, and burst pressure after pressure cycling, of composite cylinders with cuts of different depth. This test program was conducted by Lincoln Composites under contract to ASME Standards Technology LLC, and was funded by NREL. These results were considered during the development and approval of the ASME Code Cases and Code Rules. Thirteen pressure vessels with a design pressure of 24.8 MPa (3600 psi), approximately 0.406 meter (16.0 inches) in diameter and 1.02 meters (40.2 inches) long, were tested to investigate the effects of cuts to the structural laminate of a composite overwrapped pressure vessel with respect to cycling and burst pressure. Two flaws, one longitudinal and one circumferential, were machined into the structural composite. The flaws were 57 mm long by 1 mm wide (2.25 inch × 0.04 inch) and varied in depth from 10% to 40% of the structural composite thickness of 11.4 mm (0.45 inch). These pressure vessels were cycled to design pressure 0, 10,000 and 20,000 times then burst. The resulting burst pressures were evaluated against the performance of a pressure vessel without flaws or cycling. The burst pressures were affected by depth of cut, but the pressure cycling did not have a significant effect on the burst pressure.

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
John Makinson ◽  
Norman L. Newhouse

The ASME Boiler Pressure Vessel Project Team on Hydrogen Tanks, in conjunction with other ASME Codes and Standards groups, is developing Code Cases and revisions to the Boiler and Pressure Vessel Code, including such to address the design of composite pressure vessels. The Project Team had an interest in further understanding the effect of cuts to the surface of composite tanks, and how the burst pressure would be affected during the lifetime of the pressure vessel. A test program was initiated to provide data on initial burst pressure, and burst pressure after pressure cycling, of composite cylinders with cuts of different depth. This test program was conducted by Lincoln Composites under contract to ASME Standards Technology LLC, and was funded by National Renewable Energy Laboratory (NREL) [1]. These results were considered during the development and approval of the ASME Code Cases and Code Rules. Thirteen pressure vessels with a design pressure of 24.8 MPa (3600 psi), approximately 0.406 m (16.0 in.) in diameter and 1.02 m (40.2 in.) long, were tested to investigate the effects of cuts to the structural laminate of a composite overwrapped pressure vessel with respect to cycling and burst pressure. Two flaws, one longitudinal and one circumferential, were machined into the structural composite. The flaws were 57 mm long by 1 mm wide (2.25 in. × 0.04 in.) and varied in depth from 10% to 40% of the structural composite thickness of 11.4 mm (0.45 in.). These pressure vessels were cycled to design pressure 0, 10,000, and 20,000 times then burst. The resulting burst pressures were evaluated against the performance of a pressure vessel without flaws or cycling. The burst pressures were affected by depth of cut, but the pressure cycling did not have a significant effect on the burst pressure.


1994 ◽  
Vol 29 (2) ◽  
pp. 81-92 ◽  
Author(s):  
N I Crawley ◽  
D N Moreton ◽  
D G Moffat ◽  
A F Tolley

Cyclic internal pressure tests were conducted over several hundreds of cycles at pressures up to and in excess of the calculated proof test pressure on two nominally ‘identical’, stainless steel type 316 flush 90 degrees pressure vessel nozzles, designed and manufactured to BS 5500. Prior to this pressure cycling, one vessel was subjected to the required proof test of 1.25 times the design pressure. Significant incremental straining was recorded in the non-proof tested vessel during cycling at all pressures above the first yeild pressure (0.336 × design pressure). For the proof tested vessel significant incremental straining was not recorded during cycling until 15 percent above the design pressure.


2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Xian-Kui Zhu

This paper presents a critical comparison of the traditional strength criteria and the modern plastic flow criteria used in the structural design and integrity assessment of pressure vessels. This includes (1) a brief review of the traditional strength criteria used in the ASME Boiler and Pressure Vessel (B&PV) Code, (2) a discussion of the shortcomings of the traditional strength criteria when used to predict the burst pressure of pressure vessels, (3) an analysis of challenges, technical gaps, and basic needs to improve the traditional strength criteria, (4) a comparison of strength theories and plasticity theories for ductile materials, (5) an evaluation of available plastic flow criteria and their drawbacks in prediction of burst pressure of pressure vessels, (6) a description of a newly developed multiaxial yield criterion and its application to pressure vessels, and (7) a demonstration of experimental validation of the new plastic flow criterion when used to predict the burst pressure of thin-wall pressure vessels. Finally, recommendations are made for further study to improve the traditional strength design criteria and to facilitate utilization of the modern plastic flow criteria for pressure vessel design and analysis.


2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Abolfazl Zolfaghari ◽  
Moein Izadi

Abstract Pressure vessel plays an important role in wide range of applications to store gas or liquid substances. In order to design a pressure vessel safely, one of the main factors which has to be considered is selection of proper burst pressure perdition criterion. Due to large range of available materials in manufacturing of the vessels under different working conditions, several criteria to forecast burst pressure of the vessels have been developed and used by designers. Choosing the most proper criterion based on working condition and the material is a vital task to meet design requirements because inappropriate criterion may lead to unsafe vessel or over design. This issue makes not only pressure vessel design more complex but also maintenance planning, especially for designers who do not have enough experience, is a challenging task. Therefore, lack of a burst pressure predictor model, which is able to determine the pressure more accurately for wide range of materials and applications, has been remained unsolved. To evaluate machine learning techniques in prediction of burst pressure of pressure vessels, in this paper, a new model based on artificial neural network (ANN) has been proposed and developed. Input parameters of the model include internal and outer diameter, thickness, ultimate and yield strength; output is burst pressure. The obtained results showed that the constructed model has a good potential to be used as more applicable model compared to current models in design of pressure vessels.


Author(s):  
John Montoya ◽  
Donald Ketchum ◽  
Matthew Edel

It is common practice to proof test high pressure vessels prior to their use in the field. One technique for leak testing these vessels is submersion in water. A test failure at high pneumatic pressure and can pose several hazards to nearby personnel, such as projectile launch and blast loads. Submerged underwater testing can provide some level of protection from these hazards. However, it is largely unknown how much water cover is needed to prevent a projectile from escaping. The purpose of this test program was to record the mitigating effects of water on hazards caused by a sudden pressure vessel failure. The test program entails submerging a pressure vessel underwater inside a tank. The vessel is then pressurized to failure, releasing a blast wave and launching a projectile. The event is recorded using high speed photography which is used to observe the effects of the gas release and the projectile motion. A discussion of the test events and associated physics is provided.


Author(s):  
Zhiwei Chen ◽  
Tao Li ◽  
Guoyi Yang ◽  
Jinyang Zheng ◽  
Guide Deng

Abstract GB/T 34019-2017 “Ultra High Pressure Vessels” is the most important national standard that applies to pressure vessel which design pressure value is greater than or equal to 100MPa (14.5ksi). There is no standard for Ultra-high Pressure Vessel, Then this standard fills the gap in the standard system of pressure equipment in China. This paper mainly introduces the concept and main content of the new national standard, including the materials, design methods and nondestructive testing of ultra-high pressure vessel.


Author(s):  
William Koves ◽  
Elmar Upitis ◽  
Richard Cullotta ◽  
Omar Latif

Every engineering project involving the design of pressure equipment, including pressure vessels, heat exchangers and the interconnecting piping requires that the interface loads between the equipment and piping be established for the pressure vessel nozzle design and the limitations on piping end reactions. The vessel or exchanger designer needs to know the external applied loads on nozzles and the piping designer needs to know the limiting end reactions on any connected equipment. However, the final loads are not known until the piping design is completed. This requires a very good estimate of the piping end loads prior to completing the vessel or piping design. The challenge is to develop a method of determining the optimum set of design loads prior to design. If the design loads are too low, the piping design may become too costly or impractical. If the design loads are too high the vessel nozzle designs will require unnecessary reinforcement and increased cost. The problem of the stresses at a nozzle to vessel intersection due to internal pressure and external forces and moments is one of the most complex problems in pressure vessel design. The problem has been studied extensively; however each study has its own limitations. Numerous analytical and numerical simulations have been performed providing guidance with associated limitations. The objective is to establish allowable nozzle load tables for the piping designer and the vessel designer. The loads and load combinations must be based on a technically accepted methodology and applicable to all nozzle sizes, pressure classes, schedules and vessel diameters and thicknesses and reinforcement designs within the scope of the tables. The internal design pressure must also be included along with the 3 forces and 3 moments that may be acting on the nozzle and the nozzle load tables must be adaptable to all materials of construction. The Tables must also be applicable for vessel heads. This paper presents the issues, including the limitations of some of the existing industry approaches, presents an approach to the problem, utilizing systematic Finite Element Analysis (FEA) methods and presents the results in the form of tables of allowable nozzle loads.


Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1396 ◽  
Author(s):  
Biao Xiao ◽  
Bin Yang ◽  
Fu-Zhen Xuan ◽  
Yun Wan ◽  
Chaojie Hu ◽  
...  

As a result of the high specific strength/stiffness to mass ratio, filament wound composite pressure vessels are extensively used to contain gas or fluid under pressure. The ability to in-situ monitor the composite pressure vessels for possible damage is important for high-pressure medium storage industries. This paper describes an in-situ monitoring method to permanently monitor composite pressure vessels for their structural integrity. The sensor is made of a multi-walled carbon nanotube (MWCNT) that can be embedded in the composite skin of the pressure vessels. The sensing ability of the sensor is firstly evaluated in various mechanical tests, and in-situ monitoring experiments of a full-scale composite pressure vessel during hydraulic fatigue cycling and pressurization are performed. The monitoring results of the MWCNT sensor are compared with the strains measured by the strain gauges. The results show that the measured signal by the developed sensor matches the mechanical behavior of the composite laminates under various load conditions. In the hydraulic fatigue test, the relationship between the resistance and the strain is built, and could be used to quantitative monitor the filament wound pressure vessel. The bursting of the pressure vessel can be detected by the sharp increase of the MWCNT sensor resistance. Embedding the MWCNT sensor into the composite pressure vessel is successfully demonstrated as a promising method for structural health monitoring.


Author(s):  
Goldin Priscilla C P ◽  
Selwin Rajadurai J

Metallic and metal-lined polymer composite pressure vessels are extensively used in industries including aerospace. In the absence of unique failure criteria for the structural elements, phenomenological or empirical methodologies always fascinate the researchers. This paper deals with comprehensive methodologies in the prediction of burst pressure of metallic and metal-lined polymer composite pressure vessels for aerospace applications. Metallic pressure vessels are analyzed using Ansys software considering the elastic-plastic nature of materials. The progressive analysis is carried out in metal-lined composite pressure vessels in an explicit mode using Ansys software. The problem of solution convergence is discussed in detail. The extent of degradation in static analysis is suggested after multiple analysis trials. In the unit pressure extrapolation technique, stress components are evaluated using Ansys software, transformed into the local coordinate system and hence failure pressure of the first ply is identified by maximum stress criterion. Then the analysis is continued with degrading of failed layers using Ansys software and successive failures of layers are identified in steps. The results of burst pressure, evaluated through the present analyses show good agreement with the published test results. The procedures described in the paper would be of interest to the designers of pressure vessels.


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