Analysis of the load-carrying capacity of pressure vessels in the presence of through cracks

1989 ◽  
Vol 21 (11) ◽  
pp. 1454-1459
Author(s):  
N. A. Makhutov ◽  
M. I. Burak ◽  
V. B. Kaidalov
Keyword(s):  
Carrying Capacity ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Load Carrying

Investigation of Burst Pressure in T-Joints With Wall-Thinning by Using FEA

2017 ◽  
Author(s):  
Atsushi Yamaguchi
Keyword(s):  
Carrying Capacity ◽  
Safety Margin ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Load Carrying Capacity ◽  
Working Pressure ◽  
Element Analysis ◽  
T Joints ◽  
Wall Thinning ◽  
Load Carrying

Boilers and pressure vessels are heavily used in numerous industrial plants, and damaged equipment in the plants is often detected by visual inspection or non-destructive inspection techniques. The most common type of damage is wall thinning due to corrosion under insulation (CUI) or flow-accelerated corrosion (FAC), or both. Any damaged equipment must be repaired or replaced as necessary as soon as possible after damage has been detected. Moreover, optimization of the time required to replace damaged equipment by evaluating the load carrying capacity of boilers and pressure vessels with wall thinning is expected by engineers in the chemical industrial field. In the present study, finite element analysis (FEA) is used to evaluate the load carrying capacity in T-joints with wall thinning. Burst pressure is a measure of the load carrying capacity in T-joints with wall thinning. The T-joints subjected to burst testing are carbon steel tubes for pressure service STPG370 (JIS G3454). The burst pressure is investigated by comparing the results of burst testing with the results of FEA. Moreover, the maximum allowable working pressure (MAWP) of T-joints with wall thinning is calculated, and the safety margin for the burst pressure is investigated. The burst pressure in T-joints with wall thinning can be estimated the safety side using FEA regardless of whether the model is a shell model or a solid model. The MAWP is 2.6 MPa and has a safety margin 7.5 for burst pressure. Moreover, the MAWP is assessed the as a safety side, although the evaluation is too conservative for the burst pressure.

Load‐carrying capacity of spherical pressure vessels weakened by butt joints

2001 ◽  
Vol 15 (2) ◽  
pp. 153-157
Author(s):  
V V Erofeev ◽  
M V Shakhmatov ◽  
M V Erofeev ◽  
V V Kovalenko
Keyword(s):  
Carrying Capacity ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Butt Joints ◽  
Load Carrying ◽  
Spherical Pressure

Investigation of Burst Pressure in Pipes With Square Wall Thinning by Using FEA and API579 FFS-1

2013 ◽  
Author(s):  
Atsushi Yamaguchi
Keyword(s):  
Carrying Capacity ◽  
Safety Margin ◽  
Pressure Vessels ◽  
Fe Analysis ◽  
Burst Pressure ◽  
Load Carrying Capacity ◽  
Working Pressure ◽  
Accelerated Corrosion ◽  
Wall Thinning ◽  
Load Carrying

Boilers and pressure vessels are heavily used in chemical industrial plants and equipment is inspected periodically for damage. The most common type of damage is wall thinning due to Flow-Accelerated Corrosion (FAC) or corrosion under insulation (CUI). Any damage must be repaired or replaced as necessary. On the other hand, optimization of the time required in order to replace damaged equipment by evaluating the load carrying capacity of pipes with wall thinning is expected in chemical industrial field. In the present study, FE analysis is used in order to evaluate the load carrying capacity in pipes with wall thinning. Burst pressure is a measure of the load carrying capacity in pipes with wall thinning. The pipes subjected to burst testing are carbon steel tubes for pressure service STPG370 (JIS G3454). The examined wall thinning is rectangular, and the eroded depth is half the pipe wall thickness. The burst pressure is investigated by comparing the results of burst testing with the results of FE analysis. Moreover, the reduced maximum allowable working pressure (MAWPr), which is calculated by fitness-for-service (FFS) assessment, and the safety margin for burst pressure are investigated. The burst pressure calculated by FEA agrees well with the test results, except for square wall thinning for circumferential angles of less than 15°. Also, the safety margin of MAWPr based on FFS-1 Part 4 is over 4.0 times for burst pressure.

Carrying Capacity of Strain-Hardening Austenitic Stainless Steel Pressure Vessels Under Hydrostatic Pressure

2011 ◽  
Author(s):  
Yang-chun Deng ◽  
Gang Chen
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Hydrostatic Pressure ◽  
Austenitic Stainless Steel ◽  
Strain Hardening ◽  
Carrying Capacity ◽  
Plastic Instability ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Load Carrying

To reduce the waste of austenitic stainless steels due to their low yield strengths, the strain hardening technology is used to significantly improve their yield strength, in order to increase the elastic load carrying capacity of austenitic stainless steel pressure vessels. The basic principle of strain-hardening for austenitic stainless steel pressure vessels and two common models of strain hardening, including Avesta Model for ambient temperature and Ardeform Model for cryogenic temperature, were briefly introduced. However, it was fully established by experiments, the lack of a necessary theoretical foundation and the safety concern affect its widespread use. In this study, we investigated the load carrying capacity of strain-hardening austenitic stainless steel pressure vessels under hydrostatic pressure, based on the elastic-plastic theory. To understand the effects of strain hardening on material behavior, the plastic instability loads of a round tensile bar specimen were also derived under two different loading paths and validated by experiments. The results of theoretical, experimental and finite element analyses illustrated, considering the effect of material strain hardening and structural deformation, at ambient temperature, the static load carrying capacity of pressure vessels does not relate to the loading paths. To calculate the plastic instability pressures, a method was proposed so that the original dimension and original material parameters prior to strain hardening can be used either by the theoretical formula or finite element analysis. The safety margin of austenitic stainless steel pressure vessels under various strain hardening degrees was quantitatively analyzed by experiments and finite element method. A 5% strain as the restrictive condition of strain hardening design for austenitic stainless steel pressure vessels was suggested.

The Effects of the Distance Between Two Defects on the Load-Carrying Capacity of a Pressure Vessel

1999 ◽  
Vol 122 (2) ◽  
pp. 198-203
Author(s):  
H. F. Chen ◽  
D. W. Shu
Keyword(s):  
Numerical Method ◽  
Curve Fitting ◽  
Upper Bound ◽  
Carrying Capacity ◽  
Pressure Vessel ◽  
Empirical Formula ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Single Defect ◽  
Load Carrying

A simplified numerical method for both lower and upper-bound limit analyses of 3-D structure has been developed in our previous work. The load-carrying capacities of 3-D pipelines with either one or two part-through defects of various geometrical configurations were calculated by the proposed method. In the present paper, the effects of the distance between two defects on the load-carrying capacity of pressure vessels are evaluated and discussed in details. Using curve-fitting schemes, an empirical formula for obtaining the load-carrying capacity of pressure vessels with double defects from that of pressure vessels with a single defect are proposed. Some engineering suggestions are presented simultaneously. All the numerical results confirm the applicability of the simplified numerical method. [S0094-9930(00)00102-5]

Influence of Yield Strength Variability over Cross-Section to Steel Beam Load-Carrying Capacity

2005 ◽  
Vol 10 (2) ◽  
pp. 151-160 ◽  
Author(s):  
J. Kala ◽  
Z. Kala
Keyword(s):  
Yield Strength ◽  
Cross Section ◽  
Carrying Capacity ◽  
Bending Moment ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Strength Variability ◽  
Hot Rolled ◽  
Hot Rolled Steel

Authors of article analysed influence of variability of yield strength over cross-section of hot rolled steel member to its load-carrying capacity. In calculation models, the yield strength is usually taken as constant. But yield strength of a steel hot-rolled beam is generally a random quantity. Not only the whole beam but also its parts have slightly different material characteristics. According to the results of more accurate measurements, the statistical characteristics of the material taken from various cross-section points (e.g. from a web and a flange) are, however, more or less different. This variation is described by one dimensional random field. The load-carrying capacity of the beam IPE300 under bending moment at its ends with the lateral buckling influence included is analysed, nondimensional slenderness according to EC3 is λ¯ = 0.6. For this relatively low slender beam the influence of the yield strength on the load-carrying capacity is large. Also the influence of all the other imperfections as accurately as possible, the load-carrying capacity was determined by geometrically and materially nonlinear solution of very accurate FEM model by the ANSYS programme.

Fuzzy Sets Theory in Comparison with Stochastic Methods to Analyse Nonlinear Behaviour of a Steel Member under Compression

2005 ◽  
Vol 10 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Z. Kala
Keyword(s):  
Fuzzy Sets ◽  
Carrying Capacity ◽  
Stochastic Methods ◽  
Nonlinear Behaviour ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Input Parameters ◽  
Stochastic Solution ◽  
Fuzzy Solution ◽  
Sets Theory

The load-carrying capacity of the member with imperfections under axial compression is analysed in the present paper. The study is divided into two parts: (i) in the first one, the input parameters are considered to be random numbers (with distribution of probability functions obtained from experimental results and/or tolerance standard), while (ii) in the other one, the input parameters are considered to be fuzzy numbers (with membership functions). The load-carrying capacity was calculated by geometrical nonlinear solution of a beam by means of the finite element method. In the case (ii), the membership function was determined by applying the fuzzy sets, whereas in the case (i), the distribution probability function of load-carrying capacity was determined. For (i) stochastic solution, the numerical simulation Monte Carlo method was applied, whereas for (ii) fuzzy solution, the method of the so-called α cuts was applied. The design load-carrying capacity was determined according to the EC3 and EN1990 standards. The results of the fuzzy, stochastic and deterministic analyses are compared in the concluding part of the paper.

Pavement Damage Due to Conventional and New Generation of Wide-Base Super Single Tires

2005 ◽  
Vol 33 (4) ◽  
pp. 210-226 ◽  
Author(s):  
I. L. Al-Qadi ◽  
M. A. Elseifi ◽  
P. J. Yoo ◽  
I. Janajreh
Keyword(s):  
Carrying Capacity ◽  
Material Properties ◽  
Three Dimensional ◽  
Fe Analysis ◽  
Load Carrying Capacity ◽  
Inflation Pressure ◽  
3D Finite Element ◽  
Load Carrying ◽  
Pavement Damage ◽  
New Generation

Abstract The objective of this study was to quantify pavement damage due to a conventional (385/65R22.5) and a new generation of wide-base (445/50R22.5) tires using three-dimensional (3D) finite element (FE) analysis. The investigated new generation of wide-base tires has wider treads and greater load-carrying capacity than the conventional wide-base tire. In addition, the contact patch is less sensitive to loading and is especially designed to operate at 690kPa inflation pressure at 121km/hr speed for full load of 151kN tandem axle. The developed FE models simulated the tread sizes and applicable contact pressure for each tread and utilized laboratory-measured pavement material properties. In addition, the models were calibrated and properly validated using field-measured stresses and strains. Comparison was established between the two wide-base tire types and the dual-tire assembly. Results indicated that the 445/50R22.5 wide-base tire would cause more fatigue damage, approximately the same rutting damage and less surface-initiated top-down cracking than the conventional dual-tire assembly. On the other hand, the conventional 385/65R22.5 wide-base tire, which was introduced more than two decades ago, caused the most damage.

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