CN111967101A - Method for designing deep sea pressure simulation device through mechanical pressurization - Google Patents

Abstract

The invention relates to a method for designing a deep-sea pressure simulation device through mechanical compression, the method comprising the following steps: (S-1) modeling: establishing a model of a deep-sea pressure simulation device in the simulation software ANSYS, the model comprising a pressure-resistant device , the support part connected with the pressure-resistant device, and the base connected with the pressure-resistant device; (S-2) Stepwise pressurization and topology optimization: on the model established in step (S-1), through the The support part applies a simulated pressure to the pressure-resistant device, and the base is used to fix and constrain the pressure-resistant device; in the optimization process, a simulated pressure is applied to the pressure-resistant device, topology optimization is performed on the pressure-resistant device, and then the simulated pressure is increased, Topology optimization is performed again, and so on until the simulated pressure is the design pressure, and the deep-sea pressure simulation device is obtained by topology optimization. Compared with the prior art, the present invention has the advantages of fast and convenient design and high accuracy.

Description

A method for designing a deep-sea pressure simulation device by mechanical pressurization

technical field

The invention belongs to the field of design simulation for simulating deep-sea pressure, and in particular relates to a method for designing a deep-sea pressure simulation device through mechanical pressure.

Background technique

The ocean accounts for about 71% of the earth's surface area, and contains extremely rich seabed resources, including oil, natural gas, various minerals, etc. The population and economic growth have brought about a continuous increase in the demand for resources. Facing the onshore and coastal resources With the gradual exhaustion, the world will inevitably focus its future development on the deep sea field, and the development of the deep sea has become an inevitable trend.

In the key technical fields of equipment development, my country's products still cannot meet the demand, and the key supporting systems and equipment are basically monopolized by foreign countries. Therefore, it is particularly important to study and propose major special projects to ensure the construction of a marine power as soon as possible, to vigorously promote the research and development of basic, forward-looking and key technologies in the marine field, and to rapidly improve and expand the ability to go far-reaching seas.

The development of marine resources is inseparable from various mechanical testing equipment. Today, when the depth of diving has repeatedly broken through, human beings have made breakthroughs in the depth of exploration. Humans have stepped into the dark world of 7000m, or even deeper. With the deepening of research on underwater operations, human beings have put forward higher requirements for the safety and reliability of deep-sea operation equipment. In the process of research and development of deep-sea equipment, an essential step is to go through pressure tests of different indicators. For every 10m increase in seawater depth, the corresponding pressure will increase by about 0.1MPa. The marine environment is complex, and the deeper the seawater, the more difficult it is to test.

For the hydraulic system applied in the deep water environment, the influence of water pressure on the system must be considered, otherwise the hydraulic system will not work normally. At present, the test methods for seawater hydraulic components mostly use all the components to be tested on the experimental device, and the It is sent to the predetermined ocean depth for testing. This test method is not only limited by many factors, such as power supply problems and the weight of the test device, but also has a high cost and a complex test. Due to many uncertain factors on the seabed, the test is also reduced. The safety of seawater hydraulic components seriously affects the accuracy of the real performance evaluation of seawater hydraulic components. For this reason, scientists and technicians have also adopted various simulation methods. The traditional method is to place the hydraulic control components and actuators in a pressure vessel that can withstand water pressure. This method will bring the system bulky, complex structure and special A series of problems such as dynamic sealing.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for designing a deep-sea pressure simulation device through mechanical pressure in order to overcome the defects of poor accuracy and complicated design process in the prior art.

The object of the present invention can be realized through the following technical solutions:

A method for designing a deep-sea pressure simulation device by mechanical pressure, the method comprising the following steps:

(S-1) Modeling: establish a model of a deep-sea pressure simulation device in the simulation software ANSYS, and the model includes a pressure-resistant device, a support part connected to the pressure-resistant device, and a base connected to the pressure-resistant device;

(S-2) Step-by-step compression and topology optimization: on the model established in step (S-1), a simulated pressure is applied to the pressure-resistant device through the support portion, and the pressure-resistant device is fixedly constrained through the base; In the optimization process, a simulated pressure is applied to the pressure-resistant device, topology optimization is performed on the pressure-resistant device, then the simulated pressure is increased, and topology optimization is performed again, and so on until the simulated pressure is the design pressure, and the deep-sea pressure simulation device is obtained by topology optimization. .

Further, in step (S-1), the pressure-resistant device includes a casing and an internal entity provided in the casing.

Further, both the shell and the inner body are spherical, and the ratio between the diameter of the inner body, the diameter of the inner cavity of the shell, and the thickness of the shell is 250-270: 210-230: 15-25, preferably is 260:220:20.

Further, the support portion is a truncated truncated structure, and the big end of the truncated truncated structure is attached and connected to the surface of the pressure-resistant device.

Further, the ratio of the diameter of the large end of the frustum-shaped structure to the outer diameter of the casing is 150-170:250-270, preferably 160:260; the diameter, length and The ratio of the big end diameter is 40-50:300-310:155-165, preferably 45:305:160.

Further, the base is cylindrical, and the diameter of the base is equal to the diameter of the large end of the support portion.

Further, there are three supporting parts, which are a first supporting part, a second supporting part, and a third supporting part; The second support portion and the third support portion are arranged opposite to each other, the first support portion is perpendicular to the second support portion and the third support portion; the first base is arranged opposite to the first support portion, and the second support portion is arranged opposite to the first support portion. The base and the third base are arranged oppositely.

Further, in step (S-2), the initial simulated pressure is designed to be 0.05Mpa, and after each topology optimization is completed, the simulated pressure is increased by 0.1-0.2MPa, preferably 0.1MPa.

Further, in each topology optimization, the finite element analysis method is used to reduce the volume of the internal entity, and then the shape and structure of the internal entity are optimized so that the overall stiffness of the pressure-resistant device is maximized, and each point on the surface of the shell of the entire device body is guaranteed. The difference in force is less than or equal to 0.01MPa, so as to ensure that the force of each point on the surface of the shell of the main body of the device is uniform.

Each time the volume of the inner solid is reduced by no more than 50% of the volume of the entire inner solid.

Further, the material of the deep-sea pressure simulation device is titanium alloy.

The design principle of the present invention is:

The mature finite element analysis method is used, and the topology optimization technology in the software ANSYS is used to complete the optimization of the structure. Among them, topology optimization is shape optimization. ) to get the maximum or minimum value. The invention adopts the overall stiffness control method to ensure the maximum overall stiffness of the measured element and the uniformity of its stress.

Compared with the prior art, the present invention has the following advantages:

(1) The present invention adopts the design of simulation software ANSYS to avoid many unfavorable factors such as temperature, salinity, dissolved oxygen, pH value, redox potential, biofouling, calcium ion deposition and surface flow velocity related to hydrostatic pressure in marine experiments. , make the test simpler and safer, and reduce the test cost;

(2) The present invention is modeled by a suitable deep-sea pressure simulation device. During the modeling process, the support adopts a small diameter at the pressure end and a large diameter at the contact part with the spherical surface, so that the pressure can be transmitted evenly; in addition, multiple supports are used around the spherical surface. And the base can ensure the consistency of the pressure around the spherical surface after optimization. If only one support is used, it is found in the actual calculation process that it is difficult to ensure the uniformity of the pressure around the spherical surface no matter how optimized it is;

(3) In the optimization process, the present invention first sets the constraint that the volume reduction does not exceed 50%, and at the same time, after setting the shape of the optimized internal entity, the overall stiffness is the maximum value; if the volume reduction is not set in the topology optimization process , the volume may be excavated too much or too little. Too much excavated volume will result in insufficient stiffness of the sphere after optimization, and too little excavated volume will result in insufficient space in the cavity. In addition, if the maximum stiffness is not constrained, it will be difficult to ensure that the sphere will be excavated. Pressure uniformity on the back sphere surface.

Description of drawings

Fig. 1 is the modeling structure schematic diagram of the present invention;

Fig. 2 is the sectional view of the front view direction of the pressure-resistant device obtained by the present invention;

Fig. 3 is the sectional view of the top view direction of the pressure-resistant device obtained by the present invention;

Fig. 4 is the side view direction sectional view of the pressure-resistant device obtained by the present invention;

Fig. 5 is the overall equivalent stress distribution diagram of the model of the present invention;

6 is an equivalent stress distribution diagram of the deep-sea pressure simulation device of the present invention;

Fig. 7 is the cavity quasi-static pressure distribution diagram of the deep-sea pressure simulation device of the present invention;

8 is a global pressure distribution diagram of the deep-sea pressure simulation device of the present invention;

In the figure, 1 is a pressure-resistant device, 2 is a support portion, 21 is a first support portion, 22 is a second support portion, 23 is a third support portion, 3 is a base, 31 is a first base, and 32 is a second base , 33 is the third base, 4 is the solid structure, 41 is the concave structure, 42 is the supporting body, 421 is the upper bottom surface, 422 is the lower bottom surface, 423 is the side surface, 43 is the supporting branch, 44 is the first through hole, 45 is the second through hole, and 5 is the shell.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Example

A method for designing a deep-sea pressure simulation device by mechanical pressure, the method comprising the following steps:

(S-1) Modeling: A model of a deep-sea pressure simulation device is established in the simulation software ANSYS. As shown in Figure 1, the model includes a pressure-resistant device 1, a support portion 2 connected to the pressure-resistant device 1, and a pressure-resistant device 1. The base 3 to which the device 1 is connected; wherein, the pressure-resistant device 1 includes a shell 5 and an internal entity arranged in the shell 5. During modeling, the shell 5 and the internal entity are spherical; the support part 2 is a truncated cone-shaped structure and The big end of the circular truncated structure is attached to the surface of the pressure-resistant device 1, the base 3 is cylindrical, and the diameter of the base 3 is equal to the diameter of the big end of the support part 2; the structural dimension parameters of each component are shown in Table 1.

Table 1 Structural parameters

As shown in FIG. 1 , there are three supporting parts 2 , which are a first supporting part 21 , a second supporting part 22 and a third supporting part 23 ; and three bases 3 , which are a first base 31 and a second base 32 respectively. And the third base; the second support part 22 and the third support part 23 are arranged opposite, the first support part 21 is perpendicular to the second support part 22 and the third support part 23; the first base 31 is arranged opposite the first support part 21 , the second base 32 and the third base are arranged opposite to each other.

(S-2) Step-by-step compression and topology optimization: on the model established in step (S-1), a simulated pressure is applied to the pressure-resistant device 1 through the support part 2, and the pressure-resistant device 1 is fixed and constrained through the base 3; In the optimization process, the simulation pressure is applied to the pressure-resistant device 1, and the topology optimization is performed on the pressure-resistant device 1, and then the simulation pressure is increased, and the topology optimization is performed again, and so on until the simulation pressure is the design pressure.

In the step-by-step pressurization process, the initial simulated pressure is designed to be 0.05Mpa, and after each topology optimization is completed, the simulated pressure is increased by 0.1Mpa.

In each topology optimization, the finite element analysis method is used to reduce the volume of the internal entity, and then the shape and structure of the internal entity are optimized so that the overall stiffness of the pressure-resistant device 1 is maximized, and the surface of the shell 5 of the entire device body is guaranteed. The difference in force is less than or equal to 0.01MPa; the volume reduction value of each internal entity does not exceed 50% of the volume of the entire internal entity.

Figure 2, Figure 3 and Figure 4 show the final optimized structure of the deep-sea pressure simulation device. The dark part in the figure is the internal solid structure 4 formed by the remaining material of the solid part. It can be seen from the figure that the interior of the cavity is The volume of the solid portion is reduced by about 46% compared to the initial internal solid.

The optimized pressure-resistant device for deep-sea exploration is essentially a pressure vessel. The schematic structural diagrams of the deep-sea pressure-resistant device are shown in Figures 2, 3 and 4. The optimized internal structure of the pressure-resistant device 1 includes: The supporting main body 42 fixedly connected to the inner wall of the casing and the supporting branch 43 connected to the supporting main body 42, the outer side 423 of the supporting branch 43 is shape-matched and fixed on the inner wall of the casing, and the supporting branch 43 is provided with two , and the two support branches 43 are mirror-symmetrically connected to both sides of the support body 42 . The support body 42 is a columnar structure, the columnar structure includes an upper bottom surface 421 and a lower bottom surface 422 that are parallel to each other, and a side surface 423 disposed between the upper bottom surface 421 and the lower bottom surface 422, showing a structure with two ends thick and the middle thin as a whole , the edges of the upper bottom surface 421 and the lower bottom surface 422 are fixedly connected with the inner wall of the shell, and the side surface 423 in the middle is recessed toward the center of the sphere to form a recessed structure 41, which is not in contact or fixed with the inner wall of the shell, that is, between the side surface 423 and the shell Entity was also excavated. The support body 42 is provided with a first through hole 44 in the X direction and a second through hole 45 in the Y direction. The axial direction of the columnar structure is the Z direction, the X direction, the Y direction and the Z direction. Two are vertical. The cross section of the first through hole 44 is rectangular. The cross section of the second through hole 45 is rectangular. The distance between the upper bottom surface 421 and the lower bottom surface 422 is 0.3 times the diameter of the casing. The intersection of the central axis of the cylindrical structure and the casing is the vertex, and the support branch 43 extends toward the vertex. The support branch 43 is a thin shell structure whose inner side and outer side are parallel. In the axial direction of the cylindrical structure, the height of the support branch 43 is 0.6 times the radius of the housing.

As can be seen from the figure, the volume of the internal solid part of the cavity is reduced by about 46% compared to the initial internal solid.

The overall and local stress distribution of the device is further analyzed. The overall equivalent stress distribution of the entire model is shown in Figure 5. The equivalent stress distribution of the shell of the pressure-resistant device 1 is shown in Figure 6. It can be seen that the shell surface equivalent effect The force distribution is uniform, and the stress is too large in a few places because of the Saint-Venant effect in the mechanical algorithm, which does not affect the accuracy of the results. The overall static pressure distribution of the shell is shown in Figure 7, and Figure 8 is the global pressure distribution diagram. It can be seen that the pressure distribution around the cavity is uniform, so the optimized cavity structure can fully meet the requirements of the hydrostatic pressure environment for deep-sea testing, and can be used for Deep sea pressure testing.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and those skilled in the art can make various variations or modifications within the scope of the claims, which do not affect the essential content of the present invention.

Claims (10)

1. a method for designing a deep-sea pressure simulation device by mechanical pressurization, is characterized in that, the method comprises the following steps: (S-1) Modeling: a model of a deep-sea pressure simulation device is established in the simulation software ANSYS, the model includes a pressure-resistant device (1), a support portion (2) connected to the pressure-resistant device (1), and a support portion (2) connected to the pressure-resistant device (1) a base (3) to which the pressure-resistant device (1) is connected; (S-2) Step-by-step compression and topology optimization: on the model established in step (S-1), a simulated pressure is applied to the pressure-resistant device (1) through the support portion (2), and the The pressure-resistant device (1) is subjected to fixed constraints; in the optimization process, a simulated pressure is applied to the pressure-resistant device (1), topology optimization is performed on the pressure-resistant device (1), and then the simulated pressure is increased, and topology optimization is performed again, By analogy, the simulated pressure is the design pressure, and the deep-sea pressure simulation device is obtained by topology optimization. 2. A method for designing a deep-sea pressure simulation device by mechanical pressurization according to claim 1, characterized in that, in step (S-1), the pressure-resistant device (1) comprises a casing and a internal entities within the shell. 3. A method for designing a deep-sea pressure simulation device by mechanical pressurization according to claim 2, wherein the shell and the inner entity are spherical, the diameter of the inner entity, the inner void of the shell are spherical. The ratio between the diameter of the cavity and the thickness of the shell is 250-270:210-230:15-25. 4. A method for designing a deep-sea pressure simulation device by mechanical pressurization according to claim 2, wherein the support portion (2) is a truncated truncated structure and the big end of the truncated truncated structure is connected to the The surface of the pressure-resistant device (1). 5 . The method for designing a deep-sea pressure simulation device by mechanical pressurization according to claim 4 , wherein the ratio of the diameter of the large end of the frustum-shaped structure to the outer diameter of the shell is 150～50 . 170: 250-270; the proportional relationship between the diameter of the small end, the length and the diameter of the large end of the circular truncated structure is 40-50: 300-310: 155-165. 6. A method for designing a deep-sea pressure simulation device by mechanical pressure according to claim 4, wherein the base (3) is cylindrical, and the diameter of the base (3) is the same as that of the support portion (2) The diameter of the big end is equal. 7. A method for designing a deep-sea pressure simulation device by mechanical pressurization according to claim 1, characterized in that, three support parts (2) are provided, which are a first support part (21), a second support part (21), and a second support part (21). a support part (22) and a third support part (23); the base (3) is provided with three bases, which are a first base (31), a second base (32) and a third base; the second support part (22) and the third support part (23) are arranged opposite to each other, the first support part (21) is perpendicular to the second support part (22) and the third support part (23); the first base (31) ) is arranged opposite to the first support portion (21), and the second base (32) is arranged opposite to the third base. 8. A method for designing a deep-sea pressure simulation device by mechanical pressurization according to claim 1, wherein in step (S-2), the initial simulation pressure is designed to be 0.05Mpa, and after each topology optimization is completed , the simulated pressure increases by 0.1-0.2Mpa. 9. A method for designing a deep-sea pressure simulation device by mechanical pressurization according to claim 1, characterized in that, in each topology optimization, a finite element analysis method is used to reduce the volume of the internal entity, and then optimize the internal entity's volume. The shape structure makes the overall rigidity of the pressure-resistant device (1) to be the maximum value, and ensures that the stress difference of each point on the surface of the shell of the entire device main body is less than or equal to 0.01MPa. 10 . The method for designing a deep-sea pressure simulation device by mechanical compression according to claim 9 , wherein the reduction value of the volume of the internal entity each time does not exceed 50% of the volume of the entire internal entity. 11 .

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