Vibration analysis system

Abstract

To disclose one example of vibration analysis system capable of nonlinear time-domain vibration analysis for ever-changing state of contact between components.SOLUTION: In a vibration analysis system, when a mode of contact between a projection and a floor panel changes, a first model and a second model for use in analysis are changed, accordingly. The vibration analysis system is capable of nonlinear time-domain vibration analysis for ever-changing state of contact between the projection and the floor panel. The first model is a mathematical model capable of numerical analysis indicating vibration of the floor panel 2, or behavior of the floor panel 2. The second model is a mathematical model capable of numerical analysis indicating vibration of a vibration-damping panel 3, or behavior of the vibration-damping panel 3.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a vibration analysis system used for nonlinear time-axis vibration analysis in which the contact state between parts changes from moment to moment. [Background technology]

[0002] For example, the vibration analysis method described in Patent Document 1 is a vibration analysis method that assumes that a plurality of vibrating parts always vibrate as a single unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-62652 Summary of the Invention [Problem to be solved by the invention]

[0004] The vibration analysis method described in Patent Document 1 is based on the premise that multiple vibrating parts always vibrate as a single unit, and therefore cannot be used for nonlinear time-axis vibration analysis in which the contact state between parts changes from moment to moment. This disclosure discloses an example of a vibration analysis system that takes this point into consideration. [Means for solving the problem]

[0005] A vibration analysis system that is applied to a structure including a first member (2), a base portion (3A) facing the first member (2) via a gap (2A), and a second member (3) having a protrusion portion (3B) integrated with the base portion (3A) and protruding from the base portion (3A) toward the first member (2), and analyzes vibration of the structure when an excitation force is applied to the first member (2), desirably includes at least one of the following constituent elements, for example.

[0006] That is, the constituent elements are a contact pattern number determination unit that determines the number of contact patterns based on the number of protrusions (3B), a first model generation unit that generates first models in the same number as the number of contact patterns determined by the contact pattern number determination unit, the first model generation unit generating first models corresponding to each of the multiple contact patterns, a second model generation unit that generates second models in the same number as the number of contact patterns determined by the contact pattern number determination unit, the second model generation unit generating second models corresponding to each of the multiple contact patterns, and a model modification unit that modifies the first and second models used when the numerical analysis is performed to models corresponding to the contact patterns when the protrusions (3B) and the first member (2) come into contact with each other.

[0007] The first model is a mathematical model that can be numerically analyzed and shows the vibration of the first member (2), when the protrusion (3B) is separated from the first member (2). The second model is a mathematical model that can be numerically analyzed and shows the vibration of the second member (3), when the protrusion (3B) is separated from the first member (2). The number of contact patterns refers to the number of contact patterns between the protrusion (3B) and the first member (2) when the first member (2) and the second member (3) are vibrating.

[0008] As a result, in the vibration analysis system, when a change occurs in the contact mode between the protrusion (3B) and the first member (2), the first model and the second model used in the analysis are changed accordingly. Therefore, the vibration analysis system can also handle nonlinear time-axis vibration analysis in which the contact state between the protrusion (3B) and the first member (2) changes from moment to moment.

[0009] It is preferable that the model change unit of the vibration analysis system changes the first model and the second model used when the numerical analysis is performed at a timing based on the time when the protrusion (3B) separates from the first member (2). This makes it possible to perform an appropriate analysis.

[0010] Incidentally, the symbols in the above parentheses are examples showing the corresponding relationship with the specific configurations etc. described in the embodiments described below, and the present disclosure is not limited to the specific configurations etc. shown by the symbols in the above parentheses. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a diagram showing the structure of a vehicle floor. [Diagram 2] FIG. 1 is a diagram illustrating an example of a vibration damping panel. [Diagram 3] 3A to 3C are diagrams illustrating the principle of vibration suppression. [Figure 4] 4A to 4D are diagrams showing contact patterns. [Diagram 5] 1 is a functional block diagram of a vibration analysis system according to a first embodiment. FIG. [Figure 6] FIG. 11 is a diagram showing an example of a vibration analysis result. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The following "embodiment of the invention" shows an example of an embodiment that falls within the technical scope of the present disclosure. In other words, the invention-specific matters described in the claims are not limited to the specific configurations and structures shown in the following embodiment.

[0013] (First embodiment) <1. Overview of vibration analysis system> This embodiment is an example in which the vibration analysis system according to the present disclosure is applied to a vibration analysis system for analyzing vibrations occurring in a vehicle floor. The vehicle floor (hereinafter referred to as a structure) 1 includes at least a floor panel 2, a vibration control panel 3, and a silencer 4, as shown in FIG.

[0014] The floor panel 2 constitutes a part of the vehicle's framework (also called the "chassis"). The floor panel 2 according to this embodiment is a metal member such as a high-tensile steel plate. The vibration-damping panel 3 is a vibration-damping member having a base portion 3A and a plurality of protrusions 3B.

[0015] The base portion 3A is a plate-shaped portion that faces the floor panel 2 across a gap 2A. Each protrusion portion 3B is a portion that protrudes from the base portion 3A toward the floor panel 2. Each protrusion portion 3B is integrated with the base portion 3A and displaces together with the base portion 3A.

[0016] The vibration damping panel 3 according to this embodiment is an integral product in which the base portion 3A and the multiple protrusions 3B are integrally molded from an elastic resin such as rubber. As shown in FIG. 2, each protrusion 3B is a convex portion formed of multiple ridges.

[0017] The silencer 4 is a sheet-like member capable of exhibiting sound absorbing and sound insulating effects, such as a carpet. The structure 1 has a structure in which, as shown in Fig. 1, a floor panel 2, a vibration damping panel 3, and a silencer 4 are laminated in this order from the bottom.

[0018] The tip of the protrusion 3B (also referred to as the "lower end of the protrusion 3B") is only in contact with the floor panel 2, and the floor panel 2 and the vibration damping panel 3 are not integrated by adhesion or the like. The base portion 3A and the silencer 4 may be configured to be either bonded or non-bonded.

[0019] The vibration analysis system according to this embodiment is a vibration analysis system for analyzing vibration of a structure 1 such as a floor panel 2 when an excitation force acts on the chassis of a vehicle. Specifically, the vibration analysis system is used to simulate changes in vibration of a structure caused by the vibration-damping panel 3. The vibration-damping principle caused by the vibration-damping panel 3 is as follows.

[0020] When an excitation force is input to the floor panel 2 and the floor panel 2 deforms and displaces toward the vibration control panel 3 (in this embodiment, the upward side), as shown in Figure 3A, the deformation displacement (hereinafter simply referred to as "displacement") of the floor panel 2 is transmitted to the vibration control panel 3 via each protrusion 3B.

[0021] As a result, the vibration-damping panel 3 is pressed by the floor panel 2 and displaced upward integrally with the floor panel 2, so that the floor panel 2 and the vibration-damping panel 3 are curved so as to be convex upward.

[0022] Then, at the time when the direction of displacement of the floor panel 2 reverses downward, due to differences in the bending rigidity, density, etc. of the vibration control panel 3 and the floor panel 2, there is a possibility that one of the multiple protrusions 3B will move away from the floor panel 2, as shown in Figure 3B.

[0023] As time passes, the direction of displacement of the floor panel 2 may reverse to the upward direction, and the direction of displacement of the vibration damping panel 3 may reverse to the downward direction, as shown in FIG. 3C. This may cause one of the multiple protrusions 3B to come into contact with the floor panel 2.

[0024] At this time, when the protrusion 3B in contact with the floor panel 2 presses the floor panel 2 downward, the maximum amplitude of the floor panel 2 decreases. Then, by repeating the above operation, the amplitude of the floor panel 2 gradually decreases and the vibration is damped.

[0025] Furthermore, as is clear from the above description of the behavior of the floor panel 2 and the vibration-damping panel 3, when none of the protrusions 3B are in contact with the floor panel 2 (see Figure 3B), the floor panel 2 and the vibration-damping panel 3 each vibrate freely.

[0026] When any of the protrusions 3B contacts the floor panel 2, the floor panel 2 receives an excitation force from the contacted protrusion 3B. Meanwhile, the vibration control panel 3 receives a force in the opposite direction to the excitation force, that is, a reaction force to the excitation force. Hereinafter, these two excitation forces are referred to as contact excitation forces.

[0027] Therefore, the floor panel 2 receiving the contact excitation force vibrates due to a combined force of the contact excitation force and the inertial force that the panel 2 had before receiving the contact excitation force. Similarly, the vibration-damping panel 3 receiving the contact excitation force vibrates due to a combined force of the contact excitation force and the inertial force that the vibration-damping panel 3 had before receiving the contact excitation force.

[0028] <2. Details of the vibration analysis system> <2.1 Definitions of terms> The "first model" refers to a mathematical model that can be numerically analyzed to show the vibration of the floor panel 2, that is, the behavior of the floor panel 2, when the protrusion 3B is separated from the floor panel 2. Note that "numerically analyzable" means that a numerical simulation is possible.

[0029] The "second model" refers to a mathematical model that can be numerically analyzed and that shows the vibration of the vibration control panel 3, that is, the behavior of the vibration control panel 3, when the protrusion 3B is separated from the floor panel 2.

[0030] The "number of contact patterns" refers to the number of contact patterns between the protrusions 3B and the floor panel 2 when the floor panel 2 and the vibration damping panel 3 are vibrating. The number of contact patterns is defined as "2 n "

[0031] Specifically, for example, when the number of protrusions 3B is two, there are four types of contact patterns between the protrusions 3B and the floor panel 2, as shown in Figures 4A to C. In other words, when n=2, the number of contact patterns is four. Note that Figures 4A to C show the structure as a two-dimensional model.

[0032] Incidentally, Fig. 4A shows a pattern in which both of the two protrusions 3B are in contact with the floor panel 2. Fig. 4B shows a pattern in which both of the two protrusions 3B are spaced apart from the floor panel 2. Figs. 4C and 4D show patterns in which only one of the two protrusions 3B is in contact with the floor panel 2.

[0033] A "mathematical model" is a mathematical model that mimics the behavior of a structure and can be numerically analyzed by a computer (for example, a system of simultaneous equations with n dimensions and n orders with time as a parameter). "Performing numerical analysis" means solving the equations.

[0034] <2.2 Vibration analysis system configuration> The vibration analysis system has at least hardware such as a computer that performs calculations, a non-volatile memory device (hereinafter referred to as a memory device), an output device such as a display or a printer, and an input device such as a keyboard or a touch panel.

[0035] Then, the computer executes the software for the vibration analysis system to realize each functional block shown in Fig. 5, that is, the vibration analysis system 10. The computer is configured to include an arithmetic unit such as a CPU, a ROM, a RAM, a non-volatile storage unit, etc.

[0036] The software for the vibration analysis system is stored in advance in the non-volatile storage unit. The non-volatile storage device may also function as the storage device. In other words, the storage device may be a non-volatile storage device built into the computer.

[0037] <2.3 Explanation of each functional block> As shown in FIG. 5, the vibration analysis system includes a specification input unit 11, a model creation unit 12, an analysis unit 13, a data storage unit 14, and a visualization device 15.

[0038] <Specification input section> The specification input unit 11 has a function of receiving information input from an input device. The input information is information necessary for creating the above-mentioned numerical model. Specifically, the information includes dimensions, shapes, and physical properties of each part of the floor panel 2 and the vibration control panel 3, constraint conditions during numerical analysis, and input conditions such as excitation force.

[0039] <Model Creation Department> The model creation unit 12 has a function of automatically creating a mathematical model based on the information input to the specification input unit 11. The model creation unit 12 has at least a function of determining the number of contact patterns, a function of generating a first model, a function of generating a second model, and the like.

[0040] The contact pattern number determination function is a function for determining the number of contact patterns based on the number of protrusions 3 B. The first model generation function is a function for generating first models the same number as the number of contact patterns determined by the contact pattern number determination function.

[0041] The second model generating function generates second models the same number as the number of contact patterns determined by the contact pattern number determining function. Then, the first model generating function and the second model generating function each generate a first model and a second model corresponding to each of the plurality of contact patterns.

[0042] Specifically, for example, when the number of protrusions 3B is 2, the number of contact patterns is 4 (see FIGS. 4A to 4D). Therefore, the first model generation function and the second model generation function each generate a first model and a second model corresponding to FIGS. 4A to 4D, respectively.

[0043] <Analysis Department> The analysis unit 13 has at least a model modification function and an analysis function. The model change function is a function for changing the first model and the second model used when the numerical analysis is performed to a model corresponding to the contact pattern when the protrusion 3B and the floor panel 2 come into contact with each other.

[0044] Specifically, when the floor panel 2 and the vibration control panel 3 are vibrating in the state shown in Figure 4B, if the protrusion 3B comes into contact with the floor panel 2 as shown in Figure 4D, the model change function changes the first model and second model on which the numerical analysis is performed from the mathematical model corresponding to Figure 4B to the mathematical model corresponding to Figure 4D.

[0045] At this time, the model change function changes the mathematical model used when the numerical analysis is executed at a timing based on when the protrusion 3B separates from the floor panel 2. Specifically, the timing is, for example, "when it separates" or "when a predetermined time (for example, 1 second) has elapsed since it separated."

[0046] The analysis function is a function for performing a numerical analysis of a mathematical model used when performing a numerical analysis among the numerical models created by the model creation unit. The numerical analysis method is, for example, a known analysis method such as the Newmark β method.

[0047] <Data Storage Section> The data storage unit 14 stores the results of the numerical analysis in a storage device. The results to be stored include, for example, vibration data on the time axis at each node on the numerical model, the average value or overall value of the vibration data, and a frequency spectrum after frequency Fourier transform.

[0048] <Visualization display section> The visualization display unit 15 has a function of displaying the results of the numerical analysis in a graphical form on an output device (see FIGS. 4A to 4D and 6).

[0049] <3. Features of the vibration analysis system according to this embodiment> In the vibration analysis system according to this embodiment, the first model and the second model used in the analysis are changed accordingly when a change occurs in the contact mode between the protrusion 3B and the floor panel 2. Therefore, this vibration analysis system can also handle nonlinear time-axis vibration analysis in which the contact state between the protrusion 3B and the floor panel 2 changes from moment to moment.

[0050] (Other embodiments) In the above embodiment, the vibration analysis system according to the present disclosure is applied to the vibration analysis of a vehicle floor structure. However, the present disclosure is not limited to this. That is, the present disclosure is applicable to other structures, for example.

[0051] In the above-described embodiment, the structure is analyzed using a two-dimensional model in order to facilitate understanding. However, the present disclosure is not limited thereto. That is, the present disclosure is also applicable to, for example, a three-dimensional structure.

[0052] In the above embodiment, the first model and the second model are separate, but one integrated model including the first model and the second model may be used. In other words, the matrix representing the first model and the matrix representing the second model may be represented by one matrix.

[0053] When performing a numerical analysis, gap 2A may be treated as an air spring. Similarly, when performing a numerical analysis, protrusion 3B may be treated as either a linear spring or a non-linear spring.

[0054] Furthermore, the present disclosure is not limited to the above-mentioned embodiments as long as it is consistent with the gist of the disclosure described in the above-mentioned embodiments. Therefore, the present disclosure may be a configuration in which at least two of the above-mentioned embodiments are combined, or a configuration in which any of the components illustrated or the components described with reference numerals in the above-mentioned embodiments are eliminated. [Explanation of symbols]

[0055] 2. Floor panel 3. Vibration control panel 3A…Base part 3B… Protrusion 4. Silencer 10. Vibration analysis system 11... Specifications input section 12. Model Creation Section 13… Analysis department 14... Data storage section 15… Visualization display section

Claims

1. A first member; This is applied to a structure including a base portion facing the first member with a gap therebetween, and a second member having a protrusion portion integrated with the base portion and protruding from the base portion toward the first member, A vibration analysis system for analyzing vibration of a structure when an excitation force acts on the first member, comprising: a first model is a mathematical model that can be numerically analyzed and shows vibration of the first member, the mathematical model being when the protrusion is separated from the first member; a second model being a mathematical model capable of being numerically analyzed and showing vibration of the second member when the protrusion is spaced apart from the first member; When the number of contact patterns between the protrusion and the first member when the first member and the second member are vibrating is defined as a contact pattern number, a contact pattern number determination unit that determines the number of contact patterns based on the number of the protrusions; a first model generation unit configured to generate first models the same number as the number of contact patterns determined by the contact pattern number determination unit, the first model generation unit generating first models corresponding to each of the plurality of contact patterns; a second model generation unit configured to generate second models the same number as the number of contact patterns determined by the contact pattern number determination unit, the second model generation unit configured to generate second models corresponding to each of the plurality of contact patterns; a model change unit that changes a first model and a second model used when a numerical analysis is performed into a model corresponding to a contact pattern when the protrusion and the first member come into contact with each other; A vibration analysis system comprising:

2. The vibration analysis system according to claim 1 , wherein the model modification unit modifies the first model and the second model used when performing the numerical analysis at a timing based on the time when the protrusion portion separates from the first member.

3. A first member mounted on the vehicle; This is applied to a structure including a base portion facing the first member with a gap therebetween, and a second member having a protrusion portion integrated with the base portion and protruding from the base portion toward the first member, A vibration analysis system for analyzing vibration of a structure when an excitation force acts on the first member, comprising: a first model is a mathematical model that can be numerically analyzed and shows vibration of the first member, the mathematical model being when the protrusion is separated from the first member; a second model being a mathematical model capable of being numerically analyzed and showing vibration of the second member when the protrusion is spaced apart from the first member; When the number of contact patterns between the protrusion and the first member when the first member and the second member are vibrating is defined as a contact pattern number, a contact pattern number determination unit that determines the number of contact patterns based on the number of the protrusions; a first model generation unit configured to generate first models the same number as the number of contact patterns determined by the contact pattern number determination unit, the first model generation unit generating first models corresponding to each of the plurality of contact patterns; a second model generation unit configured to generate second models the same number as the number of contact patterns determined by the contact pattern number determination unit, the second model generation unit configured to generate second models corresponding to each of the plurality of contact patterns; a model change unit that changes a first model and a second model used when a numerical analysis is performed into a model corresponding to a contact pattern when the protrusion and the first member come into contact with each other; A vibration analysis system comprising:

4. A first member; This is applied to a structure including a base portion facing the first member with a gap therebetween, and a second member having a protrusion portion integrated with the base portion and protruding from the base portion toward the first member, Software for a vibration analysis system used to analyze vibration of a structure when an excitation force acts on the first member, comprising: a first model is a mathematical model that can be numerically analyzed and shows vibration of the first member, the mathematical model being when the protrusion is separated from the first member; a second model being a mathematical model capable of being numerically analyzed and showing vibration of the second member when the protrusion is spaced apart from the first member; When the number of contact patterns between the protrusion and the first member when the first member and the second member are vibrating is defined as a contact pattern number, Computer a contact pattern number determination function for determining the number of contact patterns based on the number of the protrusions; a first model generation function for generating first models the same number as the number of contact patterns determined by the contact pattern number determination function, the first model generation function generating first models corresponding to each of the plurality of contact patterns; a second model generation function that generates second models the same number as the number of contact patterns determined by the contact pattern number determination function, the second model generation function generating second models corresponding to each of the plurality of contact patterns; and A model change function for changing the first model and the second model used when the numerical analysis is performed to a model corresponding to a contact pattern when the protrusion and the first member come into contact with each other. Software for vibration analysis systems to achieve this.

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