Academic Journal of Science and Technology 
ISSN: 2771-3032 | Vol. 3, No. 3, 2022 

 

94 

Pressure	Container	Surface	Crack	Analysis	
Hao Chen, Chao Gao 

School of Mechanical Engineering, Southwest Petroleum University, Chengdu, Sichuan 610500, China 

 

Abstract: High-pressure containers are widely used in modern industries, including chemical industry, oil, nuclear power, 
aviation and many other fields. As pressure vessels are widely used in various fields, it will face a more complex and changeable 
working environment. the effects of media environment and fatigue stress cause defects, which will greatly affect the normal 
work of the container. Therefore, this article conducts static analysis of the surface with cracks on the surface through the finite 
element numerical simulation method, analyzing the rules of crack expansion and the impact on the life of pressure vessels. 
Research results: The container was stretched vertically under the load of 10MPa, and the maximum deformation occurred at the 
top of the ellipse sealed head, with a maximum deformation of 1.63mm; The maximum stress value does not occur at the top of 
the container, but occurs in the crack, and the maximum stress value is 538.18MPa; The minimum value of the safety factor of 
the safety coefficient cloud diagram is 0.50, which is located at the crack. The intensity of cracks has a great impact on the 
intensity of high -pressure containers. It needs to be checked regularly on high -pressure containers to ensure the safe operation 
of the equipment. 

Keywords: High-pressure container, Finite element numerical simulation, Crack, Static analysis. 
 

1. Introduction 
High-pressure container is a closed equipment between 

10MPa and 100MPa [1]. It is widely used in modern industries. 
It includes many fields such as chemical industry, petroleum, 
pharmaceutical, nuclear energy and aviation [2]. The necessary 
key equipment during operations. It is a key equipment for the 
storage, mixing, transportation, response and other operations 
of the material [3]. 

High-pressure containers have a history of more than a 
hundred years, and their use in industry is not very long. As 
early as the late 19th century, with the needs of industrial 
development, people began to realize the importance and 
inevitability of high -pressure containers, and the ideas of 
high -pressure technology research have germinated. 
Subsequently, in 1910, German chemist Haber and 
Rossingnol first obtained industrial products for synthetic 
ammonia at 10MPa and 500 °C. Two years later, the German 
chemist Claude further developed on the basis of this to 
increase the pressure to 100MPa. Since then, in order to 
improve the efficiency of industrial production, various 
countries have begun to encourage the development of high-
pressure container technology [4-5]. At present, the equipment 
in the synthetic ammonia technology can reach 15-60MPa, 
the equipment in the hydrogenation technology is 8-70MPa, 
and the equipment pressure in polyethylene device can even 
be as high as 150-250MPa [6-8]. 

In the normal operating environment and service life, when 
the stress in a certain place in the container is too large, and 
the shape and performance change, the phenomenon of losing 
work capacity is called the failure of the pressure container [8-

10]. As a special pressure container, high -pressure container, 
once it fails, will affect production progress, increase the cost 
of engineering, and endanger personal safety. High-pressure 
container harsh and special working conditions make its 
failure forms of complex and changeable characteristics. Its 
failure form is strength failure, stiffness failure, stability 
failure, corrosion failure, etc [11-16].  

  With the needs of industrial technology, high-pressure 
containers are widely used and the working environment is 
complicated, which often leads to cracks in pressure vessels, 
which will greatly affect the normal work of the equipment. 
In this article, this article analyzes the laws and changes in 
stress container crack expansion and changes in stress. The 
results of this article will be of great significance to 
understanding cracks on pressure containers. 

2. Pressure Container Numerical 
Model 

2.1. Numerical modeling 
Try to analyze the effects of cracks on the design pressure 

of 10MPa, observe the pressure and strain distribution of the 
container, explore the impact of cracks on the container, and 
calculate the life of the pressure container. The model is 
shown in Fig 1. The basic size is 1.84m inner diameter, 4.0m 
in length, 0.16m wall thickness, 1.84m inner diameter of the 
sealed head, and 0.16m wall thickness. 

 

Figure 1. 3D model 



 

95 

2.2. Definition of material attributes and 
boundary condition settings 

The pressure container material is Q345, the elastic 
modulus of the material and the specific parameters of Poine 
ratio are 1.92 × 105MPa, and 0.3. First, apply a fixed 
constraint on the pressure vessel, and then apply 10MPa to the 
inside of the container. The application of the load is shown 
in Fig 2. 

 

 

Figure 2. The container load is applied  

2.3. Set the division of the surface cracks of the 
container and the grid 

Set the ellipse crack, insert Fraction in the model, insert the 
crack (Semi-Elliptical) through the Fracture, and set the crack 
parameter settings. Major Radius is set to 100mm, and the 
minor radius is 50mm, and the maximum contour radius is 
50mm. The ellipse crack setting is shown in Fig 3, and the 
grid is divided into Fig 4, including the overall grid and crack 
grid. 

 

 

Figure 3. Settings of cracks 

 

Figure 4. Grid division 

3. Results analysis 

3.1. Pressure container stress 
From the perspective of the total strain cloud diagram in 

Fig 5, the container is stretched vertically under the load of 
10MPa, causing the container to deform both vertical and 
horizontally. The maximum deformation occurs at the top of 
the oval head, the maximum deformation is 1.63mm, and the 
maximum variable volume of the horizontal direction occurs 
at the contact part of the cylindrical part of the export to take 
over the container, with a maximum deformation of 0.41mm. 

Through observing the Fig 6, the maximum stress value is 
not the top of the container, but occurs in the crack. The 
maximum stress value is 538.18MPa, while the maximum 
stress value of other parts does not exceed 300.90MPa. 
Because the container material is Q345 and the yield strength 
is 345MPa, the container is under 10MPa pressure, because 
the existence of cracks will cause yield deformation. 

 

 

Figure 5. Strain cloud map 

 
Figure 6. Specification and crack stress cloud map 

3.2. Crack analysis 
Select the Fracture Tool Fracture tool insertion in Solution, 

click the stress intensity factor (SIFS (K1)), J points (J-
Integral) to solve, and the results are shown in Figure 7 and 8 
respectively. Fig 7 Display the range of stress intensity factor 
is 268.46 ~ 400.93MPA.mm^(0.5), indicating that the tip of 
the crack is the easiest position. Fig 8 shows that when the J 
points is 0.74, the cracking stress reaches the critical value of 
the cracks to start expansion, and the crack will begin to 
expand. 



 

96 

 
Figure 7. Stress intensity factor cloud diagram 

 

 
Figure 8. J Point Cloud Map 

3.3. Container life 
Select the Fatigue Tool fatigue computing tool insertion in 

Solution, click Fatigue Tool to set the parameter settings, the 
load ratio is set to 0.67, the Mean Stress theory is set to 
Goodman, and other parameters are unchanged, as shown in 
Fig 9. For the analysis of the fatigue life of pressure vessels, 
the life cloud diagram is shown in Fig 10. Under the stress 
ratio conditions, the fatigue container has a greater fatigue 
damage. The main reason is that the existence of the crack 
greatly reduces the fatigue life of the container. It can be seen 
from the safety factor cloud chart 11 that the minimum safety 
factor of the container is 0.49824, which is located at the crack. 

 

 
Figure 9. Parameter settings 

 
Figure 10. Lifetime Cloud Map 

 

 
Figure 11. Safety Coefficient Cloud Map 

4. Summary 
(1) The container is stretched vertically under the load of 

10MPa, and the maximum deformation occurs at the top of 
the ellipse sealed head, with a maximum deformation of 
1.63mm; 

(2) The maximum stress value is not the top of the 
container, but occurs in the crack, and the maximum stress 
value is 538.18MPa; 

(3) The safety factor cloud diagram shows that the 
minimum safety factor of the container is 0.50, which is 
located at the crack. The intensity of the crack has a great 
impact on the intensity of high-pressure containers. It is 
necessary to regularly check the high-pressure container to 
ensure the safe operation of the equipment. 

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