Strength of Cylinders Containing Radial or Offset Cross-Bores

1976 ◽  
Vol 18 (6) ◽  
pp. 279-286 ◽  
Author(s):  
B. N. Cole ◽  
G. Craggs ◽  
I. Ficenec
Keyword(s):  
Fatigue Life ◽  
Pressure Vessel ◽  
Cyclic Stress ◽  
Stress Conditions ◽  
Bursting Pressure ◽  
Centre Line ◽  
Cylindrical Pressure Vessel ◽  
The Cross ◽  
Static Conditions ◽  
Radial Centre

The introduction of a small transverse opening or cross-bore into the wall of a cylindrical pressure vessel is sometimes necessary. Under static conditions such a cross-bore may have little effect on the bursting pressure of a plain cylinder, but under cyclic stress conditions, the fatigue life of the vessel is severely reduced. If the cross-bore axis is offset from the radial centre-line of the cylinder, then the fatigue life of such a vessel is shown to be substantially greater than that of a similar vessel containing a radial cross-bore.

Strategy for Cross-Bores in High Pressure Containers

1969 ◽  
Vol 11 (2) ◽  
pp. 151-161 ◽  
Author(s):  
B. N. Cole
Keyword(s):  
High Pressure ◽  
Fatigue Life ◽  
Cross Section ◽  
Pressure Vessel ◽  
Working Pressure ◽  
Circular Section ◽  
Centre Line ◽  
Cylindrical Pressure Vessel ◽  
Von Mises ◽  
Safe Working

It is frequently necessary to drill a cross-bore through the wall of a cylindrical pressure vessel, and it tends to be taken for granted that the cross-bore—itself of circular section— should lie along a diameter of the main cross-section. The weakening effect of such a hole is well known, and reduces the safe working pressure down to 2/5 of the value for the undisturbed cylinder in the case of a Tresca material, or nearly down to 1/3 in the case of a von Mises material. The paper shows how it is possible to reclaim a large proportion of the ‘lost’ pressure capacity by use of a cross-bore which is either elliptical in section, or, more conveniently, round but offset from a diametral centre-line. Such procedure could thus also greatly improve the fatigue life of the pressure vessel.

scholarly journals INVESTIGATION OF MULTI-CYCLE FATIGUE OF EQUIPMENT AND MACHINERY ELEMENTS UNDER COMPLEX STRESS CONDITIONS AND NON- STATIONARY LOADING

2020 ◽  
Vol 3 (77) ◽  
pp. 11-17
Author(s):  
S. J. JASEN ◽  
◽  
D. K. JAKIYEV ◽  
S. S. ZHUNISBEKOV ◽  
◽  
...  
Keyword(s):  
Experimental Data ◽  
Fatigue Life ◽  
Cyclic Stress ◽  
Complex Stress ◽  
Stress Conditions ◽  
Energy Concentration ◽  
Structural Elements ◽  
Cycle Fatigue ◽  
Stationary Loading ◽  
Comparison Of The Results

A computational and experimental method for estimating the fatigue life of structural elements of machines operating under complex cyclic stress conditions and non-stationary loading is considered. Comparison of the results of the calculations and experimental data indicated the effectiveness of the kinetic equation of multi-cycle fatigue damage based on the energy concentration of fatigue failure.

Pressure-vessel support brackets: Stresses due to dead loads

1967 ◽  
Vol 2 (1) ◽  
pp. 1-16 ◽  
Author(s):  
R Kitching ◽  
B E Olsen
Keyword(s):  
Spherical Shell ◽  
Strain Gauge ◽  
Pressure Vessel ◽  
Elastic Shell ◽  
Design Methods ◽  
Centre Line ◽  
Conventional Design ◽  
Cylindrical Pressure Vessel ◽  
Support Reaction

The investigation is concerned with the elastic shell stresses occurring when vertical loads are transmitted through discrete support brackets welded to the lower hemispherical end of a cylindrical pressure vessel having its axis vertical. Three sizes of bracket were examined, and the largest was compared with a similar arrangement having an internal bracket continuous with the external one. Strain-gauge results indicated that shell stresses may be calculated by assuming that the radial deflection of the spherical shell is linearly distributed along the line of contact between bracket and shell. Conventional design methods employed in stress calculations tended to underestimate the shell stresses. It is shown that the line of application of the support reaction in relation to the centre line of the bracket is most important.

Effects of Geometric Misalignment Caused by Girth Weld on Fatigue Behavior of a Cylindrical Pressure Vessel

2012 ◽  
Vol 479-481 ◽  
pp. 1066-1069
Author(s):  
Musharaf Abbas ◽  
Rehan Qayyume ◽  
Jamal Hussain Afridi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Pressure Vessel ◽  
Fatigue Behavior ◽  
Fe Analysis ◽  
Element Analysis ◽  
Critical Areas ◽  
Cylindrical Pressure Vessel ◽  
Geometrical Effects

The paper presents the results of finite element analysis of a pressurized vessel typically made of steel 1025 and containing the weld misalignment at the cylinder-to-cylinder junction. This misalignment considered in the vessel’s structure is because of girth weld that is found in most of the fabrications of such type of structures. Geometric misalignment of 50% of thickness is considered for this particular study. The work evaluates the geometrical effects of misalignment on the fatigue behavior of the pressure vessel to quantify its consequences in term of fatigue life and maximum damage. Finite Element (FE) analysis is performed by the use of ANSYS on one quarter of the structure due to symmetry. A significant effect of misalignment on fatigue life of the cylinder has been found and is presented with maximum anticipated damage in the critical areas.

scholarly journals Experimental study on fatigue performance of Q420qD high-performance steel cross joint in complex environment

2021 ◽  
Author(s):  
Haigen Cheng ◽  
Cong Hu ◽  
Yong Jiang
Keyword(s):  
Fatigue Life ◽  
High Performance ◽  
Steel Structure ◽  
Steel Structures ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Corrosive Media ◽  
Joint Connection ◽  
High Performance Steel ◽  
The Cross

AbstractThe steel structure under the action of alternating load for a long time is prone to fatigue failure and affects the safety of the engineering structure. For steel structures in complex environments such as corrosive media and fires, the remaining fatigue life is more difficult to predict theoretically. To this end, the article carried out fatigue tests on Q420qD high-performance steel cross joints under three different working conditions, established a 95% survival rate $$S{ - }N$$ S - N curves, and analyzed the effects of corrosive media and high fire temperatures on its fatigue performance. And refer to the current specifications to evaluate its fatigue performance. The results show that the fatigue performance of the cross joint connection is reduced under the influence of corrosive medium, and the fatigue performance of the cross joint connection is improved under the high temperature of fire. When the number of cycles is more than 200,000 times, the design curves of EN code, GBJ code, and GB code can better predict the fatigue life of cross joints without treatment, only corrosion treatment, and corrosion and fire treatment, and all have sufficient safety reserve.

A Study on Fatigue Life Evaluation of Pressure Vessel Made of ASME SA240-316L Material Using Numerical Analysis

2019 ◽  
Vol 893 ◽  
pp. 1-5 ◽  
Author(s):  
Eui Soo Kim
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Pressure Vessel ◽  
Life Prediction ◽  
Pressure Vessels ◽  
Physical Damage ◽  
Element Analysis ◽  
Internal Damage ◽  
Life Evaluation ◽  
Fatigue Life Evaluation

Pressure vessels are subjected to repeated loads during use and charging, which can causefine physical damage even in the elastic region. If the load is repeated under stress conditions belowthe yield strength, internal damage accumulates. Fatigue life evaluation of the structure of thepressure vessel using finite element analysis (FEA) is used to evaluate the life cycle of the structuraldesign based on finite element method (FEM) technology. This technique is more advanced thanfatigue life prediction that uses relational equations. This study describes fatigue analysis to predictthe fatigue life of a pressure vessel using stress data obtained from FEA. The life prediction results areuseful for improving the component design at a very early development stage. The fatigue life of thepressure vessel is calculated for each node on the model, and cumulative damage theory is used tocalculate the fatigue life. Then, the fatigue life is calculated from this information using the FEanalysis software ADINA and the fatigue life calculation program WINLIFE.

scholarly journals Effect of Mean Stress on the Fatigue Life Prediction of Notched Fiber-Reinforced 2060 Al-Li Alloy Laminates under Spectrum Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Weiying Meng ◽  
Liyang Xie ◽  
Yu Zhang ◽  
Yawen Wang ◽  
Xiaofang Sun ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Linear Model ◽  
Life Prediction ◽  
Piecewise Linear ◽  
Forecast Accuracy ◽  
Cyclic Stress ◽  
Fatigue Life Prediction ◽  
Fiber Reinforced ◽  
Piecewise Linear Model ◽  
Spectrum Loading

This paper presents a study on the fatigue life prediction of notched fiber-reinforced 2060 Al-Li alloy laminates under spectrum loading by applying the constant life diagram. Firstly, a review on the state of the art of constant life diagram models for the life prediction of composite materials is given, which highlights the effect on the forecast accuracy. Then, the fatigue life of notched fiber-reinforced Al-Li alloy laminates (2/1 laminates and 3/2 laminates) is tested under cyclic stress, which has different stress cycle characteristics (constant amplitude loading and Mini-Twist spectrum loading). The introduced models are successfully realized based on the available experimental data of examined laminates. In the case of Mini-Twist spectrum loading, the effect of the constant life diagram on the life prediction accuracy of examined laminates is studied based on the rainflow-counting method and Miner damage criteria. The results show that the simple Goodman model and piecewise linear model have certain advantages compared to other complex models for the life prediction of notched fiber metal laminates with different structures under Mini-Twist loading. From the engineering perspective, the S-N curve prediction based on the piecewise linear model is most applicable and accurate among all the models.

A Study of Nozzles in Pressure Vessels under Pressure Fatigue Loading

1967 ◽  
Vol 182 (1) ◽  
pp. 657-684 ◽  
Author(s):  
J. Spence ◽  
W. B. Carlson
Keyword(s):  
Fatigue Life ◽  
Mild Steel ◽  
Pressure Vessel ◽  
Special Interest ◽  
Maximum Stress ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Pressure Vessels ◽  
Full Size

Nozzles in cylindrical vessels have been of special interest to designers for some time and have offered a field of activity for many research workers. This paper presents some static and fatigue tests on five designs of full size pressure vessel nozzles manufactured in two materials. Supporting and other published work is reviewed showing that on the basis of the same maximum stress mild steel vessels give the same fatigue life as low alloy vessels. When compared on the basis of current codes it is shown that mild steel vessels may have five to ten times the fatigue life of low alloy vessels unless special precautions are taken.

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