JP4952485B2 - Deformation simulation method for flexible tube - Google Patents

Description

  The present invention relates to a deformation simulation method for a flexible tube.

In an engine room of an automobile, a hose (hereinafter referred to as a flexible tube) for transporting fluid, for example, a flexible tube for transporting air to an air conditioner, or a flexible tube for supplying hydraulic pressure to a power steering device is provided. It has been incorporated.
In recent years, the density of the engine room has been increased, and the clearance between the flexible pipe and other parts and structures tends to be narrowed. Therefore, the flexible pipe in a state where the flexible pipe is assembled in the engine room. It is important to accurately grasp the trajectory, that is, the deformation behavior at the design stage.
Therefore, by using CAD software, the trajectory of the flexible tube is drawn based on a combination of simplified geometric shapes such as spline curves, straight lines, and arcs.
However, the trajectory of the flexible tube reproduced by such a combination of geometric shapes does not take into account the material characteristics of the flexible tube in the reproduction, so the flexible tube actually assembled in the engine room is not considered. The trajectory is often different, and the flexible tube may interfere with other members and structures.
Therefore, techniques for analyzing the trajectory of the flexible tube using a finite element method have been proposed (see Patent Documents 1 and 2).
JP-A-3-108070 JP-A-5-216920

However, in the above-described prior art, actual torsional rigidity and bending rigidity are obtained using an actually manufactured flexible tube, and analysis is performed using the actual measurement data. Therefore, there is a disadvantage in improving the efficiency of design and reducing the cost.
In addition, since the flexible tube is analyzed as a solid solid element or a beam element, the flexible tube is expanded and shaken due to the fluid pressure acting inside the flexible tube. The deformation behavior cannot be reflected in the analysis result, and there is a disadvantage that the deformation behavior of the flexible tube in the use state cannot be obtained accurately.
The present invention has been made in view of such circumstances, and its object is to improve the design efficiency and reduce the design cost, and is advantageous in accurately reproducing the deformation behavior of the flexible tube. It is to provide a deformation simulation method of a flexible tube.

  To achieve the above object, the present invention provides a deformation simulation method for a flexible tube, wherein the deformation behavior of the flexible tube in a state where both ends of the flexible tube are attached to a structure is analyzed by a finite element method using a computer. The computer includes an input unit that receives an operation input by an operator, an analysis unit that performs an analysis process using a finite element method, and an output unit that outputs data. A shape data input step for giving shape data indicating the shape of the flexible tube to the analysis means by performing operation input, and the analysis means divides the flexible tube into elements based on the shape data, and a plurality of elements A structure data generation step for generating structure data by setting a plurality of nodes, and the operator can perform the operation by performing an operation input to the input means. A material property setting step for setting material property data indicating a material property of a tube in the analysis unit; and constraint condition data indicating a constraint condition of the flexible tube by an operator performing an operation input on the input unit. A constraint condition setting step set in the analysis means, and an amount of movement and a position of the both ends when the operator attaches both ends of the flexible tube to the structure by performing an operation input to the input means. A boundary condition setting step for setting boundary condition data indicating boundary conditions to be set in the analysis means; and the structure data generated by the analysis means in the structure data generation step and the material characteristic data set in the material characteristic setting step. And the constraint condition data set in the constraint condition setting step and the boundary condition data set in the boundary condition setting step First data showing a deformation behavior in a no-load state in which the pressure does not act on the inner peripheral surface of the flexible tube in a state where both ends of the flexible tube are attached to the structure by performing calculation by an elementary method And a pressure for setting pressure data indicating pressure acting on the inner peripheral surface of the flexible tube when the operator performs an operation input to the input means in the analysis means. A setting step; and the analysis means includes the structure data generated in the structure data generation step, the material property data set in the material property setting step, the constraint condition data set in the constraint condition setting step, and the boundary condition Based on the boundary condition data set in the setting step and the pressure set in the pressure setting step, calculation is performed by a finite element method, and both ends of the flexible tube are attached to the structure. And a second data output step of outputting second data indicating a deformation behavior in a loaded state in which the pressure is applied to the inner peripheral surface of the flexible tube in a cut state.

  According to the present invention, the first data indicating the deformation behavior in the no-load state in which the pressure does not act on the inner peripheral surface of the flexible tube when both ends of the flexible tube are attached to the structure, and the flexible tube Since the second data indicating the deformation behavior in a load state where pressure is applied to the inner peripheral surface of the flexible tube is obtained, the deformation behavior of the flexible tube caused by the fluid pressure acting on the inside of the flexible tube is obtained. This can be reflected in the analysis result, and the deformation behavior of the flexible tube in the use state can be obtained accurately.

Next, a flexible tube deformation simulation method according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a computer 10 used for executing the method of the present invention, and FIG. 2 is a functional block diagram of the computer 10.
First, the computer 10 that executes the method of the present invention will be described.
As shown in FIG. 1, a computer 10 includes a CPU 12, a ROM 14, a RAM 16, a hard disk device 18, a disk device 20, a keyboard 22, a mouse 24, a display 26, and a printer connected via an interface circuit (not shown) and a bus line. 28 and so on.
The ROM 14 stores a control program and the like, and the RAM 16 provides a working area.
The hard disk device 18 stores an analysis program for realizing the flexible tube deformation simulation method according to the present invention.
The disk device 20 records and / or reproduces data on a recording medium such as a CD or a DVD.
The keyboard 22 and the mouse 24 receive an operation input by the operator, and constitute the input means 10A (FIG. 2).
The display 26 displays and outputs data, and the printer 28 prints and outputs data. The display 26 and the printer 28 constitute output means 10C (FIG. 2).

As shown in FIG. 2, the computer 10 functionally includes an input means 10A, an analysis means 10B, and an output means 10C.
The input unit 10A receives operation input by an operator and inputs data necessary for analyzing the flexible tube by the finite element method, which will be described later.
The analysis means 10B performs analysis processing by the finite element method based on the data input by the input means 10A. The analysis program stored in the hard disk device 18 shown in FIG. This is realized by operating based on an analysis program.
The output means 10C outputs data composed of the calculation results by the analysis means 10B.

Next, the flexible tube analyzed by the method of the present invention will be described.
3A is a front view of the flexible tube 40, and FIG. 3B is a side view of the flexible tube 40.
In the present embodiment, the case where the flexible tube 40 is assembled in an engine room of an automobile and transports fluid will be described.
As shown in FIGS. 3 (A) and 3 (B), the flexible tube 40 is formed into a cylindrical shape by a flexible material, and an internal space S for transporting a fluid is formed therein. In the present embodiment, the flexible tube 40 has a cylindrical shape.
The flexible tube 40 is assembled in the engine room by attaching both ends 40A and 40B in the longitudinal direction to the attachment locations in the engine room.
In the present embodiment, as shown in FIG. 3A, the flexible tube 40 includes a tube layer 42, a reinforcing member 44, and a cover layer 46.
The tube layer 42 is formed in a cylindrical wall shape facing the internal space S, and is formed of a material that does not leak the fluid transported through the internal space S to the outside of the tube layer 42, such as rubber.
The reinforcing member 44 is provided on the tube layer 42 in order to reinforce the strength of the tube layer 42. In the present embodiment, the reinforcing member 44 has a cylindrical shape over the longitudinal direction and the circumferential direction of the flexible tube 40 inside the tube layer 42 in the thickness direction (radial direction), as indicated by a two-dot chain line in the figure. Is embedded as such.
The cover layer 46 is provided in a cylindrical wall shape so as to cover the outer peripheral surface of the tube layer 42, and protects the tube layer 42.
In other words, the flexible tube 40 includes a base material composed of a tube layer 42 and a cover layer 46 formed in a tubular shape, and a reinforcing member 44 provided on the base material to reinforce the base material. Made of composite material.
As the reinforcing member 44, for example, a fiber material or a metal material can be adopted, and one layer or a plurality of layers are provided.

Next, a deformation simulation method of the flexible tube 40 will be described with reference to the flowchart of FIG.
5 (A) and 5 (B) are explanatory views schematically showing the movement when the flexible tube 40 is attached.
When the flexible tube 40 is attached to the engine room, one end 40A of the flexible tube 40 extending linearly is fixed to the attachment position g of the engine room, as shown in the position (A) of FIG. Next, as shown in the position (b), the other end 40B of the flexible tube 40 is displaced from the initial position e to the intermediate position e ′.
4B, the other end 40B of the flexible tube 40 is displaced from the intermediate position e ′ to the attachment position e ″, and the other end 40B is fixed at the attachment position e ″. .
In analyzing and reproducing the movement of the flexible tube 40 using the finite element method, the position of each part of the flexible tube 40 is expressed with reference to the three-dimensional coordinates on the drawing showing the engine room. Since the origin and coordinate axes of the upper three-dimensional coordinates are defined regardless of the movement of the flexible tube 40, there is a disadvantage that the calculation at the time of analysis becomes complicated.
Therefore, the coordinates indicating the three-dimensional space of the engine room are converted from the three-dimensional coordinates on the drawing to the three-dimensional coordinates for finite element method analysis so that the calculation at the time of analysis is simplified (step S10).
5A and 5B, three-dimensional coordinates for finite element analysis are defined by coordinates on the X, Y, and Z axes that are orthogonal to each other.
Then, as shown in FIG. 5A, the position of one end 40A of the flexible tube 40 extending in a straight line indicated by the position (A) is set as the origin of the X axis and the Y axis, and the other end 40B is set as the X axis. It is assumed that the upper coordinate is e and the flexible tube 40 extends on the X axis.
As described above, both ends 40A and 40B of the flexible tube 40, the attachment location, or the intermediate location of the flexible tube 40 is located on any of the X axis, Y axis, Z axis, XY plane, YZ plane, and XZ plane. In this way, the calculation at the time of analysis is simplified by performing conversion to three-dimensional coordinates for the finite element method analysis.
Note that such coordinate conversion processing is not essential, but performing conversion processing as in the present embodiment is advantageous in simplifying calculation during analysis and shortening analysis time.

Next, a boundary condition that defines the amount of movement and the position of both ends 40A and 40B when attaching both ends 40A and 40B of the flexible tube 40 to the attachment location is calculated (step S12).
As shown in FIGS. 5A and 5B, the boundary conditions are positions of both ends 40A and 40B when the flexible tube 40 is moved in the order of position (A), position (B), and position (C). Indicates the amount of movement.
In the example of FIG. 5, when moving the flexible tube 40 from the position (A) to the position (B), first, the other end 40B of the flexible tube 40 is inclined by φ degrees with respect to the X axis, and the position e ′. And then moved to the position e ″ while maintaining the angle φ of the flexible tube 40. Therefore, in the example of FIG. 5, the position and the movement amount indicating the boundary condition are the angle φ and the other end 40B described above. This is expressed by the amount of movement of the coordinates (indicated by lx and ly in the figure).

Next, when the operator inputs an operation to the input unit 10A, the shape data D1 (FIG. 2) indicating the shape of the flexible tube 40 is given to the analysis unit 10B (step S14: shape data input step).
The shape data D1 includes, for example, the length, outer diameter, and inner diameter of the flexible tube 40, and the shapes and structures of the tube layer 42, the reinforcing member 44, and the cover layer 46 that constitute the flexible tube 40. More specifically, it includes the number of layers of the reinforcing member 44 and the orientation direction of the fiber member constituting the reinforcing member 44.
Next, the analysis means 10B generates structure data by dividing the flexible tube 40 into elements based on the shape data D1 and setting a plurality of elements and a plurality of nodes (step S16: structure data generation step).
In the element division by this structural data generation step, the tube layer 42 and the cover layer 46 which are the base materials of the flexible tube 40 are modeled by shell elements or solid elements, and the reinforcing member 44 is modeled by reinforcing element. Made in
That is, when modeling the flexible tube 40, the flexible tube 40 is strictly modeled as a hollow tube body using a shell element or a solid element, and the characteristics of the reinforcing member 44 are strictly defined using a reinforcing material element. Reflect and model.
The reinforcing element is already used in a commercially available finite element method analysis program. For example, in ABAQUS (registered trademark), which is a finite element method analyzing program of Dassault Systèmes, the reinforcing element is called a river element. Used in the name.

Next, the operator sets the material property data D2 (FIG. 2) indicating the material properties of the flexible tube 40 in the analysis unit 10B by performing an operation input on the input unit 10A (step S18: material property setting). Step).
In the present embodiment, the material property data D2 of the tube layer 42, the reinforcing member 44, and the cover layer 46 is set.
Examples of material properties include Young's modulus, Poisson's ratio, density (mass density), and the like.

Next, the operator sets constraint condition data D3 (FIG. 2) indicating constraint conditions for restraining each node of the structure data of the flexible tube 40 to the analysis unit 10B by performing an operation input on the input unit 10A. (Step S20: constraint condition setting step).
The constraint condition is to set a fixed or free degree of freedom (6 degrees of freedom) of each node for each node, and is set based on a conventionally known finite element method.

Next, the operator sets the boundary condition data D4 indicating the boundary condition calculated in step S12 in the analysis means 10B by performing an operation input on the input means 10A (step S22: boundary condition data setting). Step).
That is, the boundary condition data D4 indicating the boundary conditions that define the movement amounts and positions of the both ends 40A, 40B when the both ends 40A, 40B of the flexible tube 40 are attached to a structure or the like is set in the analysis means 10B.

Next, the analysis means 10B includes the structure data generated in the structure data generation step, the material property data D2 set in the material property setting step, the constraint condition data D3 set in the constraint condition setting step, and the boundary condition. Calculation is performed by the finite element method based on the boundary condition data D4 set in the data setting step, and pressure is applied to the inner peripheral surface of the flexible tube 40 with both ends of the flexible tube 40 being attached to the structure. The first data D10 (FIG. 2) indicating the deformation behavior (the trajectory of the flexible tube 40) in the unloaded state is output via the output means 10C (step S24: first data output step).
In the present embodiment, the data D10 output from the output means 10C is obtained as the displacement amount data D10 indicating the displacement amount of the node.
The displacement amount data D10 is expressed by, for example, an image showing the flexible tube 40 three-dimensionally, but it is arbitrary in what form the displacement amount data D10 is output and expressed.

FIG. 6 is an explanatory diagram showing the deformation behavior of the flexible tube 40 in the no-load state drawn based on the displacement amount data D10 output in the first data output step. 6 to 8 show a case where the deformation behavior of the flexible tube 40 is shown on a two-dimensional plane.
That is, as shown by the position (A), the flexible tube 40 extending linearly with the one end 40A fixed is moved to the position (B), and then the flexible tube 40 is moved to the position (C). The state which moved the other end 40B to the attachment position is shown.
In the drawing, a thick solid line indicated by a symbol (d) indicates a deformation behavior (trajectory) of the flexible tube 40 obtained based on a combination of simplified geometric shapes such as a spline curve, a straight line, and an arc. Therefore, it can be seen that the bending of the intermediate portion of the flexible tube 40 is not reflected in comparison with the deformation behavior (trajectory) of the flexible tube 40 indicated by the displacement amount data D10 obtained by the analyzing means 10B.

And based on the obtained analysis result (data indicating the deformation behavior of the flexible tube 40), by confirming the proximity of the distance between the flexible tube 40 and other members or structures, the presence or absence of interference, etc. Then, the design evaluation of the flexible tube 40 is performed (step S26: evaluation step). If the design is evaluated as inappropriate, the design is changed (step S34), and the processing is repeated from step S14.
FIG. 7 shows a case where the total length of the flexible tube 40 is changed to two types.
That is, when the total length of the flexible tube 40 is changed to two types of L1 and L2 (L2> L1), the deformation behavior when the total length of the flexible tube 40 is L1 and L2 is the position (e) and the position, respectively. (To)
It can be seen that the bending of the intermediate portion of the flexible tube 40 is larger when the total length of the flexible tube 40 is longer than L1 as compared to the case of L1.

If the evaluation in step S26 is appropriate, the pressure data D5 (FIG. 2) indicating the pressure acting on the inner peripheral surface of the flexible tube 40 when the operator inputs the operation to the input means 10A is analyzed 10B. (Step S28: Pressure data setting step).
The setting of the pressure data D5 by the pressure setting step may be such that a static pressure acts so that the pressure becomes constant regardless of the passage of time, or the pressure changes with the passage of time. In other words, in other words, dynamic pressure may be applied.

Next, the analysis means 10B includes the structure data generated in the structure data generation step, the material property data D2 set in the material property setting step, the constraint condition data D3 set in the constraint condition setting step, and the boundary condition. Based on the boundary condition data D4 set in the data setting step and the pressure data D5 set in the pressure data setting step, calculation is performed by the finite element method, and both ends of the flexible tube 40 are attached to the structure. 2nd data D12 (FIG. 2) which shows the deformation | transformation behavior in the load state which the said pressure acted on the internal peripheral surface of the flexible tube 40 is output via the output means 10C (step S30: 2nd data output step) ).
In the present embodiment, the second data D12 output from the output means 10C is also obtained as the displacement amount data D12 indicating the displacement amount of the node. That is, the displacement amount data D12 reflects the expansion and vibration of the flexible tube 40 that is generated when pressure is applied to the flexible tube 40.
The displacement amount data D12 is also expressed by an image or the like showing the flexible tube 40 three-dimensionally, but it is arbitrary in what form it is output and expressed.

And based on the obtained analysis result (data indicating the deformation behavior of the flexible tube 40), by confirming the proximity of the distance between the flexible tube 40 and other members or structures, the presence or absence of interference, etc. Then, the design evaluation of the flexible tube 40 is performed (step S32: evaluation step). If the design is evaluated as inappropriate, the design is changed (step S34), and the processing is repeated from step S14.
If it is determined in step S32 that the design is appropriate, the series of processing ends.

FIG. 8 is an explanatory diagram showing deformation behavior of the flexible tube 40 in an unloaded state and a loaded state.
That is, the deformation behavior of the flexible tube 40 in an unloaded state is indicated by a solid line (position (c)), and the deformation behavior in a loaded state is indicated by a broken line (position (g)).
When a load due to pressure is applied to the flexible tube 40, the flexible tube 40 is stretched or shaken, so that the middle portion of the flexible tube 40 is slightly larger than the unloaded flexible tube 40. You can see that

6 to 8 show the case where the deformation behavior of the flexible tube 40 is shown on a two-dimensional plane, it is also possible to show the deformation behavior of the flexible tube 40 on a three-dimensional plane.
FIG. 9 is an explanatory view three-dimensionally showing the deformation behavior of the flexible tube 40 in an unloaded state. FIG. 9A is a front view of the flexible tube 40, and FIG. (C) is a C arrow view of (B). FIG. 10 is an explanatory view three-dimensionally showing the deformation behavior of the flexible tube 40 under load. FIG. 10A is a front view of the flexible tube 40, and FIG. The figure and (C) are C arrow line views of (B).
Also in this case, it is understood that the bending degree of the intermediate portion of the flexible tube 40 is changed (increased) as compared with the unloaded flexible tube 40 due to the pressure applied to the flexible tube 40.

As described above, according to the present embodiment, the deformation behavior in the no-load state in which the pressure does not act on the inner peripheral surface of the flexible tube 40 with both ends of the flexible tube 40 attached to the structure. First data D10 to be shown, and second data D12 to show deformation behavior in a load state in which pressure is applied to the inner peripheral surface of the flexible tube 40 with both ends of the flexible tube 40 being attached to the structure. Therefore, the deformation behavior of the flexible tube 40 caused by the fluid pressure acting inside the flexible tube 40 can be reflected in the analysis result, and the deformation behavior of the flexible tube 40 in the use state can be reflected. Can be obtained accurately.
In addition, as in the prior art, it is not necessary to obtain actual measurement data of torsional rigidity and bending rigidity using an actually manufactured flexible pipe, and there is no need to perform analysis using these actual measurement data. The deformation behavior of the flexible tube can be obtained without using it.
Therefore, it is advantageous in accurately reproducing the deformation behavior of the flexible tube while improving the design efficiency and reducing the design cost.

In the present embodiment, when modeling the flexible tube 40, the flexible tube 40 is strictly modeled as a hollow tube body using a shell element or a solid element.
Therefore, it is more advantageous in accurately reproducing the deformation behavior of the flexible tube 40 than when the flexible tube 40 is modeled by a solid solid element or a beam element as in the prior art.
Further, in the present embodiment, modeling is performed by strictly reflecting the characteristics of the reinforcing member 44 using the reinforcing element.
Therefore, in the case where the flexible tube 40 has the reinforcing member 44, it is even more advantageous in accurately reproducing the deformation behavior of the flexible tube 40.
Further, instead of using such a reinforcing material element, the material property data indicating the material property of the reinforcing member 44 is included in the material property data of the flexible tube 40 set by the material property setting step. The flexible tube 40 may be modeled by reflecting the characteristics of the reinforcing member 44. In this case as well, when the flexible tube 40 has the reinforcing member 44, the deformation behavior of the flexible tube 40 is accurately determined. This is advantageous for reproduction.
In the case where the reinforcing member 44 has anisotropy in strength, if the material characteristic data indicating the anisotropy of the reinforcing member 44 is included as the material characteristic data of the reinforcing member 44, the reinforcing member 44 is different. The flexible tube 40 can be modeled by reflecting the directionality, which is more advantageous in accurately reproducing the deformation behavior of the flexible tube 40.

In the present embodiment, the case where the mass of the fluid passing through the inside of the flexible tube 40 is not considered has been described. However, when the fluid needs to be considered like the liquid, the operator must A fluid density setting step for setting fluid density data indicating the mass density of the fluid passing through the inside of the flexible tube 40 by performing an operation input to the input means 10A is further added to the analysis means 10B. The output steps S24 and S30 of the first and second data D10 and D12 are calculated based on the load applied to the flexible tube 40 by the mass of the fluid inside the flexible tube 40 obtained from the fluid density data set in the fluid density setting step. You may make it reflect.
In this case, since the mass of the fluid in the flexible tube 40 is reflected, it is even more advantageous in accurately reproducing the deformation behavior of the flexible tube 40.

In the present embodiment, the case where the method of the present invention is executed using one computer 10 has been described. However, as shown in FIG. 11, data communication with the computer 10 via the network 32 is performed. A communication device 30 is provided, and a communication system in which two or more computers 10 are connected so as to be able to perform data communication via a network 32 such as a LAN or the Internet, and the method of the present invention is executed using such a communication system. May be.
That is, the first computer that constitutes the input means 10A and the output means 10C and the second computer that constitutes the analysis means 10B are constituted by separate computers 10, and the exchange of data between the means is performed on the network 32. You may implement | achieve the method of this invention by performing via.
Further, a third computer for storing the analysis result obtained by the analyzing means 10B is provided connected to the network 32, and the analysis result stored in the third computer is transmitted to the computer other than the third computer via the network 32. It is arbitrary such as reading from.

  In the present embodiment, the case where the flexible tube is assembled in the engine room of the automobile and transports the fluid has been described. However, the flexible tube to be analyzed by the method of the present invention is limited to this. For example, a flexible tube for supplying hydraulic pressure for driving heavy machinery, a flexible tube for transporting oil or food, or various liquids or gases (gas) in a chemical factory, etc. Various types of conventionally known flexible tubes such as a flexible tube for transporting the liquid are included.

It is a block diagram which shows the structure of the computer 10 used in order to perform the method of this invention. 2 is a functional block diagram of a computer 10. FIG. (A) is a front view of the flexible tube 40, and (B) is a side view of the flexible tube 40. 4 is a flowchart showing an operation of a deformation simulation method for a flexible tube 40; (A), (B) is explanatory drawing which shows typically the motion at the time of the attachment of the flexible tube 40. FIG. It is explanatory drawing which shows the deformation | transformation behavior in the unloaded state of the flexible tube. It is explanatory drawing which shows the deformation | transformation behavior of the flexible tube 40 at the time of changing the full length of the flexible tube 40 into two types. It is explanatory drawing which shows the deformation | transformation behavior in the unloaded state and load state of the flexible tube. It is explanatory drawing which shows three-dimensionally the deformation | transformation behavior in the unloaded state of the flexible tube 40, (A) is a front view of the flexible tube 40, (B) is a B arrow view of (A), (C ) Is a C arrow view of (B). It is explanatory drawing which shows the deformation | transformation behavior in the load state of the flexible tube 40, (A) is a front view of the flexible tube 40, (B) is a B arrow view of (A), (C). FIG. 6 is a view as viewed from the arrow C in (B). 2 is an explanatory diagram showing an example in which a plurality of computers 10 are connected via a network 32. FIG.

Explanation of symbols

  10: Computer, 10A: Input means, 10B: Analysis means, 10C: Output means, 40: Flexible tube, D1: Shape data, D2: Material property data, D3: Restriction condition data, D4: Boundary condition data, D5: Pressure data, D10: First data, D12: Second data.

Claims (8)

A deformation simulation method for a flexible tube, wherein the deformation behavior of the flexible tube in a state where both ends of the flexible tube are attached to a structure is analyzed using a computer by a finite element method,
The computer includes input means for receiving an operation input by an operator, analysis means for performing analysis processing by a finite element method, and output means for outputting data,
A shape data input step of giving shape data indicating the shape of the flexible tube to the analysis means by an operator performing an operation input on the input means;
A structure data generating step for generating structure data by dividing the flexible tube into elements based on the shape data and setting a plurality of elements and a plurality of nodes;
A material property setting step of setting material property data indicating the material property of the flexible tube in the analysis unit by performing an operation input to the input unit by an operator;
A constraint condition setting step of setting constraint condition data indicating a constraint condition of the flexible tube in the analysis unit by an operator performing an operation input on the input unit;
Boundary condition data indicating boundary conditions defining the amount and position of movement of both ends of the flexible tube when the operator attaches both ends of the flexible tube to the structure by performing an operation input to the input means. A boundary condition setting step to be set to
The analysis unit sets the structure data generated in the structure data generation step, the material property data set in the material property setting step, the constraint condition data set in the constraint condition setting step, and the boundary condition setting step. A non-load state in which the pressure does not act on the inner peripheral surface of the flexible tube in a state where both ends of the flexible tube are attached to the structure based on the boundary condition data A first data output step of outputting first data indicating the deformation behavior at
A pressure setting step for setting pressure data indicating pressure acting on the inner peripheral surface of the flexible tube by the operator performing an operation input on the input means in the analysis means;
The analysis unit sets the structure data generated in the structure data generation step, the material property data set in the material property setting step, the constraint condition data set in the constraint condition setting step, and the boundary condition setting step. Finite element method based on the set boundary condition data and the pressure set in the pressure setting step, the inner peripheral surface of the flexible tube with both ends of the flexible tube attached to the structure A second data output step of outputting second data indicating deformation behavior in a load state where the pressure is applied to
A method for simulating deformation of a flexible tube. The element division by the structure data generation step is performed by modeling the flexible tube with a shell element or a solid element.
The deformation simulation method for a flexible tube according to claim 1. The flexible tube includes a base material formed in a tubular shape and a reinforcing member provided on the base material to reinforce the base material.
The element division by the structural data generation step is performed by modeling the base material with a shell element or a solid element and modeling the reinforcing member with a reinforcing element.
The deformation simulation method for a flexible tube according to claim 1. The flexible tube includes a base material formed in a tubular shape and a reinforcing member provided on the base material to reinforce the base material.
The element division by the structure data generation step is performed by modeling the flexible tube with a shell element or a solid element,
The material property data of the flexible tube set by the material property setting step includes material property data indicating the material property of the reinforcing member,
The deformation simulation method for a flexible tube according to claim 1. The reinforcing member has anisotropy in strength,
The material property data indicating the material property of the reinforcing member includes material property data indicating the anisotropy of the reinforcing member.
The deformation simulation method for a flexible tube according to claim 4, wherein: A fluid density setting step of setting fluid density data indicating mass density of fluid passing through the inside of the flexible tube by the operator performing an operation input to the input means in the analysis means;
The calculation by the analyzing means reflects a load acting on the flexible tube due to the mass of the fluid inside the flexible tube obtained from the fluid density data set in the fluid density setting step.
The deformation simulation method for a flexible tube according to claim 1. Data indicating the deformation behavior of the flexible tube output by the output step is indicated by displacement amounts of the plurality of nodes.
The deformation simulation method for a flexible tube according to claim 1. The setting of the pressure data in the pressure setting step is such that the pressure becomes constant regardless of the passage of time, or the pressure changes with the passage of time.
The deformation simulation method for a flexible tube according to claim 1.

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