A viscoelastic-plastic mechanics model teaching demonstration instrument and its use method

Abstract

The present invention discloses a viscoelastic-plastic mechanics model teaching demonstration instrument, comprising a single-model testing mechanism, a serial dual-model testing mechanism, and a parallel dual-model testing mechanism, wherein the single-model testing mechanism, the serial dual-model testing mechanism, and the parallel dual-model testing mechanism each comprise a test rod, a test model disposed on the test rod, a load applicator disposed at both ends of the test rod, and an electronic extensometer for collecting deformation of the test model, wherein the electronic extensometer communicates with a computer via a signal receiver, and the computer is connected to the load applicator via a data cable for controlling the magnitude of an output load. The present invention adopts the viscoelastic-plastic mechanics model teaching demonstration instrument of the above structure, which can intuitively describe in the form of images the different mechanical behaviors exhibited by the three basic mechanical properties of elasticity, plasticity, and viscosity when combined in different forms, and can solve the sense of abstraction generated by using only language and mathematical formulas for description, making the teaching process smoother, and enabling students to more intuitively and vividly understand and accept the mechanical meaning of the mathematical model describing the mechanical behavior of materials.

Description

Technical Field

[0001] The present invention relates to a mechanics teaching demonstration instrument technology, and in particular to a viscoelastic-plastic mechanics model teaching demonstration instrument and a use method thereof. Background Art

[0002] To describe the influence of time on the stress-strain relationship of soil, time-dependent models (such as viscoelastic models, elastoplastic models, viscoplastic models, and viscoelastic-plastic models) are needed to describe soil properties. Viscoelastic models are further divided into the Maxwell model and the Kelvln model.

[0003] Figure 1 is the stress change diagram of the Maxwell model, such as Figure 1 As shown in the figure, the Maxwell model consists of a linear spring and a viscometer in series, also known as a relaxation model. In this model, the total strain remains unchanged after the object obtains the initial strain, but a relaxation phenomenon occurs in which the stress decays over time.

[0004] Figure 2 is the stress change diagram of Kelvln model, such as Figure 2 As shown in the figure, the Kelvln model is composed of a linear spring and a viscoelastic pot in parallel, also known as a non-relaxation model. Its total strain should be the sum of the strains of the two elements, and when time tends to infinity, its strain tends to a stable value.

[0005] The viscoelastic model can also be further expanded into a three-element model, such as a linear spring and a Kelvln model in series, or other composition forms. By continuing to add elements, a more complex model can be obtained. The most commonly used ones are the generalized Maxwell model and the generalized Kelvln model.

[0006] The viscoplastic model is composed of a visco-pot component and a plastic slicing component to represent the visco-plasticity of the material, among which the Bingham model is composed of a visco-pot and a plastic slicing component in parallel. Figure 3 is the stress change diagram of the Bingham model, such as Figure 3 As shown in the figure, deformation begins only when the stress reaches the yield limit. Before that, it becomes rigid, and after yielding, it exhibits viscoplastic properties.

[0007] The viscoelastic-plastic model can express the three properties simultaneously. Figure 4 is the viscoelastic-plastic model diagram, such as Figure 4 As shown in Figure 1, elastic and viscoplastic strains are considered separately, consisting of a spring and viscoplastic model connected in series. Because this type of mechanical model, combining the three properties of viscoelasticity, elasticity, and plasticity, is key to studying the stress-strain relationship in soil, it is a key teaching focus.

[0008] The current teaching model for viscoelastic-plastic mechanics typically involves the instructor verbally explaining the principles in a textbook, or through classroom lectures and some blackboard writing. This approach to teaching the model is often dull and difficult to grasp, significantly diminishing the quality of instruction. Even with the addition of blackboard drawings, the explanation remains monotonous and lacks a more vivid and engaging approach, failing to achieve the desired effect and hindering students' understanding of the relationship between the three properties.

[0009] That is, the prior art lacks a demonstration instrument that can vividly demonstrate the relationship between the three properties. Summary of the Invention

[0010] To address the above issues, the present invention aims to provide a viscoelastic-plastic mechanics model teaching demonstration instrument. By combining viscoelasticity and plasticity and displaying their deformation process on the instrument, students can observe the actual deformation process, thereby gaining a deeper understanding and lessening the feeling of unfamiliarity and boredom. Furthermore, being able to actually see the real thing greatly aids understanding and memory. Furthermore, the various combinations of the three basic properties can broaden students' thinking and aid memory and understanding by understanding the differences and similarities between the various properties.

[0011] To achieve the above-mentioned objectives, the present invention provides a viscoelastic-plastic mechanics model teaching demonstration instrument, comprising a single-model testing mechanism, a serial dual-model testing mechanism, and a parallel dual-model testing mechanism. The single-model testing mechanism, the serial dual-model testing mechanism, and the parallel dual-model testing mechanism all comprise a test rod, a test model arranged on the test rod, a load applicator arranged at both ends of the test rod, and an electronic extensometer for collecting the deformation of the test model. The electronic extensometer communicates with a computer via a signal receiver, and the computer is connected to the load applicator via a data cable for controlling the magnitude of the output load.

[0012] Preferably, the single-model testing mechanism, the serial dual-model testing mechanism and the parallel dual-model testing mechanism are sequentially arranged in layers above and below inside the transparent protective shell.

[0013] Preferably, the test model of the single-model testing mechanism includes a horizontally arranged spring assembly, a sticky pot assembly and a plastic scribe assembly, and the spring assembly, the sticky pot assembly and the plastic scribe assembly are respectively arranged inside the transparent protective shell through the test rod.

[0014] Preferably, the test models of the series dual-model testing mechanism include a horizontally arranged viscoelastic series model, an elastoplastic series model, and a viscoplastic series model, and the viscoelastic series model, the viscoelastic series model, the elastoplastic series model, and the viscoplastic series model are respectively arranged inside the transparent protective shell via the test rod;

[0015] The elastic-viscous series model includes the spring component and the viscosity pot component connected in series;

[0016] The elastic-plastic series model includes the spring component and the plastic dicing component connected in series;

[0017] The viscous-plastic series model includes the viscous pot component and the plastic dicing component connected in series.

[0018] Preferably, the test models of the parallel dual-model testing mechanism include a horizontally arranged viscoelastic parallel model, an elastoplastic parallel model, and a viscoplastic parallel model, and the viscoelastic parallel model, the viscoelastic parallel model, the elastoplastic parallel model, and the viscoplastic parallel model are respectively arranged inside the transparent protective shell via the test rod;

[0019] The elastic-viscous parallel model includes the spring component and the viscosity pot component connected in parallel;

[0020] The elastic-plastic parallel model includes the spring component and the plastic dicing component connected in parallel;

[0021] The viscous-plastic parallel model includes the viscous pot component and the plastic dicing component in parallel.

[0022] Preferably, the spring assembly is a linear spring; the sticky pot assembly is a sticky pot, also known as a damper; the plastic slicing assembly is mainly composed of two contact blocks arranged in sequence along the direction of the test rod, and the two contact blocks are in close contact through the contact surface, and the contact surface is arranged parallel to the test rod.

[0023] Preferably, the load applicator is connected to the computer via a conversion button provided on the transparent protective shell for switching the experimental mode.

[0024] Preferably, the load applicator includes a body and a drive motor arranged at both ends of the test rod, the body is connected to the drive motor, the drive motor is connected to the computer, and the drive motor is arranged inside the transparent protective shell.

[0025] The method of using the viscoelastic-plastic mechanics model teaching demonstration instrument includes the following steps:

[0026] S1. Use the switch to select the experimental mode;

[0027] S2. The computer turns on the corresponding load applying instrument and controls the load applying instrument to output the set load value;

[0028] S3, using an electronic extensometer to collect deformation information of the corresponding test model, and transmitting the deformation information to a computer;

[0029] S4. The computer draws a stress-strain relationship diagram based on the collected deformation information.

[0030] Preferably, the experimental mode in step S1 includes one of a single mode experiment, a series dual mode experiment, and a parallel dual mode experiment, and any combination thereof;

[0031] The single mode experiment includes one of an elastic experiment, a viscosity experiment and a plastic experiment, and any combination thereof;

[0032] The series dual-mode experiment includes one of an elastic-viscous series experiment, an elastic-plastic series experiment, and a viscous-plastic series experiment, and any combination thereof;

[0033] The parallel dual-mode experiment includes one of an elastic-viscous parallel experiment, an elastic-plastic parallel experiment, and a viscous-plastic parallel experiment, and any combination thereof.

[0034] Therefore, the present invention adopts the viscoelastic-plastic mechanics model teaching demonstration instrument of the above structure, which can vividly describe the combination of the three basic properties of elasticity, plasticity and viscosity, and the different properties and different constitutive relationships reflected in the soil by different combinations. It can solve the sense of abstraction generated by only language description, making the teaching process smoother and the teaching results more significant.

[0035] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the stress change diagram of the Maxwell model;

[0037] Figure 2 is the stress change diagram of Kelvln model;

[0038] Figure 3 is the stress change diagram of Bingham model;

[0039] Figure 4 is the viscoelastic-plastic model diagram;

[0040] Figure 5 It is a structural schematic diagram of the viscoelastic-plastic mechanics model teaching demonstration instrument of the present invention.

[0041] Among them: 1. Load applicator, 2. Transparent protective shell, 3. Switch button, 4. Spring assembly, 5. Sticky pot assembly, 6. Plastic scribe assembly, 7. Data cable, 8. Drive motor, 9. Signal receiver, 10. Computer. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the accompanying drawings. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to this embodiment.

[0043] Figure 5 Schematic diagram of the structure of the viscoelastic-plastic mechanics model teaching demonstration instrument of the present invention, as shown in FIG. Figure 5 As shown, the structure of the present invention includes a single model testing mechanism, a serial dual model testing mechanism and a parallel dual model testing mechanism. The single model testing mechanism, the serial dual model testing mechanism and the parallel dual model testing mechanism all include a test rod, a test model arranged on the test rod, a load applicator 1 arranged at both ends of the test rod, and an electronic extensometer for collecting the deformation of the test model. The electronic extensometer communicates with a computer 10 via a signal receiver 9, and the computer 10 is connected to the load applicator 1 via a data line 7 for controlling the magnitude of the output load.

[0044] Preferably, the single model testing mechanism, the series dual model testing mechanism and the parallel dual model testing mechanism are sequentially arranged in layers inside the transparent protective shell 2, that is, the multiple models are independently arranged in layers for students to observe each model.

[0045] Preferably, the test model of the single-model testing mechanism includes a horizontally arranged spring assembly 4 (Hooke's model), a viscosity pot assembly 5 (Newtonian viscosity model), and a plastic slicing assembly (rigid-plastic model 6). The spring assembly 4, the viscosity pot assembly 5, and the plastic slicing assembly 6 are respectively arranged inside the transparent protective shell 2 via the test rod. Preferably, the spring assembly 4 is a linear spring; the viscosity pot assembly 5 is a damper (the damper is filled with viscous liquid and a movable piston); and the plastic slicing assembly is mainly composed of two contact blocks arranged in sequence along the direction of the test rod. The two contact blocks are in close contact via a contact surface, and the contact surface is arranged parallel to the test rod (that is, there is a symmetrical friction resistance on the contact surface, which is independent of the normal pressure acting on the surface and is a constant. There is no external force in the demonstration instrument that affects this resistance).

[0046] Preferably, the test model of the series dual-model testing mechanism includes a horizontally arranged viscoelastic series model, an elastoplastic series model, and a viscoplastic series model, and the viscoelastic series model, the viscoelastic series model, the elastoplastic series model, and the viscoplastic series model are respectively arranged inside the transparent protective shell 2 via the test rod;

[0047] The viscoelastic series model includes the spring component 4 and the viscoelastic pot component 5 connected in series;

[0048] The elastic-plastic series model includes the spring component 4 and the plastic scribe component 6 connected in series;

[0049] The viscoplastic series model includes the visco-pot component 5 and the plastic dicing component 6 connected in series.

[0050] Preferably, the test model of the parallel dual-model testing mechanism includes a horizontally arranged viscoelastic parallel model, an elastoplastic parallel model, and a viscoplastic parallel model, and the viscoelastic parallel model, the viscoelastic parallel model, the elastoplastic parallel model, and the viscoplastic parallel model are respectively arranged inside the transparent protective shell 2 via the test rod;

[0051] The viscoelastic parallel model includes the spring component 4 and the viscoelastic pot component 5 connected in parallel;

[0052] The elastic-plastic parallel model includes the spring component 4 and the plastic dicing component 6 connected in parallel;

[0053] The viscoplastic parallel model includes the visco-pot component 5 and the plastic dicing component 6 connected in parallel.

[0054] Preferably, the load applicator 1 is connected to the computer 10 via a conversion button provided on the transparent protective shell 2 for switching the experimental mode.

[0055] Preferably, the load applicator 1 includes a main body and a drive motor 8 arranged at both ends of the test rod, the main body is connected to the drive motor 8, the drive motor 8 is connected to the computer 10, and the drive motor 8 is arranged inside the transparent protective shell 2.

[0056] The method of using the viscoelastic-plastic mechanics model teaching demonstration instrument includes the following steps:

[0057] S1. Use the switch to select the experimental mode;

[0058] S2. The computer 10 turns on the corresponding load applying instrument 1 and controls the load applying instrument 1 to output the set load value;

[0059] S3, using an electronic extensometer to collect deformation information of the corresponding test model, and transmitting the deformation information to a computer 10;

[0060] S4. The computer 10 draws a stress-strain relationship diagram based on the collected deformation information. It should be noted that the principle of using the computer 10 to draw the relationship diagram is common knowledge in the field, so it will not be described here in detail.

[0061] Preferably, the experimental mode in step S1 includes one of a single mode experiment, a series dual mode experiment, and a parallel dual mode experiment, and any combination thereof;

[0062] The single-mode experiment includes one of elastic experiments, viscosity experiments and plastic experiments and any combination thereof. The elastic experiment, viscosity experiment and plastic experiment correspond to the operation of the spring component 4 (corresponding to the operation of the load applicator 1 of the spring component 4), the operation of the viscosity pot component 5 and the operation of the plastic slicing component 6 respectively; the series dual-mode experiment includes one of elastic-viscosity series experiment, elastic-plastic series experiment and viscosity-plastic series experiment and any combination thereof. The elastic-viscosity series experiment, elastic-plastic series experiment and viscosity-plastic series experiment correspond to the operation of the spring viscosity pot series model, the spring plastic slicing series model and the viscosity pot plastic slicing series model respectively; the parallel dual-mode experiment includes one of elastic-viscosity parallel experiment, elastic-plastic parallel experiment and viscosity-plastic parallel experiment and any combination thereof. The elastic-viscosity parallel experiment, elastic-plastic parallel experiment and viscosity-plastic parallel experiment correspond to the operation of the spring viscosity pot parallel model, the spring plastic slicing parallel model and the viscosity pot plastic slicing parallel model respectively. It should also be noted that the working principle of switching the working mode via the switch button 3 is common knowledge in the art, so it will not be described here in detail.

[0063] Therefore, the present invention adopts the viscoelastic-plastic mechanics model teaching demonstration instrument of the above structure, which can vividly describe the combination of the three basic properties of elasticity, plasticity and viscosity, and the different properties and different constitutive relationships reflected in the soil by different combinations. It can solve the sense of abstraction generated by only language description, making the teaching process smoother and the teaching results more significant.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A viscoelastic-plastic mechanics model teaching demonstration instrument, characterized by: The invention comprises a single-model test mechanism, a serial dual-model test mechanism and a parallel dual-model test mechanism, wherein each of the single-model test mechanism, the serial dual-model test mechanism and the parallel dual-model test mechanism comprises a test rod, a test model arranged on the test rod, a load applicator arranged at both ends of the test rod, and an electronic extensometer for collecting deformation of the test model, wherein the electronic extensometer communicates with a computer via a signal receiver, and the computer is connected to the load applicator via a data line for controlling the magnitude of the output load; The single-model test mechanism, the serial dual-model test mechanism, and the parallel dual-model test mechanism are sequentially arranged in layers inside the transparent protective shell; The test model of the single-model test mechanism includes a horizontally arranged spring assembly, a sticky pot assembly, and a plastic scribing assembly, wherein the spring assembly, the sticky pot assembly, and the plastic scribing assembly are respectively arranged inside the transparent protective shell via the test rod; The load applying instrument is connected to the computer via a conversion button provided on the transparent protective shell for switching the experimental mode.

2. The viscoelastic-plastic mechanics model teaching demonstration device according to claim 1, characterized in that: The test models of the series dual-model test mechanism include a horizontally arranged viscoelastic series model, an elastoplastic series model, and a viscoplastic series model, wherein the viscoelastic series model, the elastoplastic series model, and the viscoplastic series model are respectively arranged inside the transparent protective shell via the test rod; The viscoelastic series model includes the spring component and the viscoelastic pot component connected in series; The elastic-plastic series model includes the spring component and the plastic scribe component connected in series; The viscoplastic series model includes the visco-pot component and the plastic dicing component connected in series.

3. The viscoelastic-plastic mechanics model teaching demonstration device according to claim 2, characterized in that: The test models of the parallel dual-model test mechanism include a horizontally arranged viscoelastic parallel model, an elastoplastic parallel model, and a viscoplastic parallel model, wherein the viscoelastic parallel model, the elastoplastic parallel model, and the viscoplastic parallel model are respectively arranged inside the transparent protective shell via the test rod; The viscoelastic parallel model includes the spring component and the viscoelastic pot component connected in parallel; The elastic-plastic parallel model includes the spring component and the plastic dicing component connected in parallel; The viscoplastic parallel model includes the visco-pot component and the plastic dicing component connected in parallel.

4. The viscoelastic-plastic mechanics model teaching demonstration device according to claim 1, characterized in that: The spring assembly is a linear spring; the sticky pot assembly is a sticky pot, also known as a damper; the plastic dicing assembly is mainly composed of two contact blocks arranged in sequence along the direction of the test rod, and the two contact blocks are in close contact through the contact surface, and the contact surface is arranged parallel to the test rod.

5. The viscoelastic-plastic mechanics model teaching demonstration device according to claim 1, characterized in that: The load applicator includes a body and a drive motor arranged at both ends of the test rod, the body is connected to the drive motor, the drive motor is connected to the computer, and the drive motor is arranged inside the transparent protective shell.

6. A method for using the viscoelastic-plastic mechanics model teaching demonstration device according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Use the switch to select the experimental mode; S2. The computer turns on the corresponding load applying instrument and controls the load applying instrument to output the set load value; S3, using an electronic extensometer to collect deformation information of the corresponding test model, and transmitting the deformation information to a computer; S4. The computer draws a stress-strain relationship diagram based on the collected deformation information.

7. The method for using the viscoelastic-plastic mechanics model teaching demonstration device according to claim 6, characterized in that: The experimental mode in step S1 includes one of a single mode experiment, a series dual mode experiment, and a parallel dual mode experiment, and any combination thereof; The single mode experiment includes one of an elastic experiment, a viscosity experiment and a plastic experiment, and any combination thereof; The series dual-mode experiment includes one of an elastic-viscous series experiment, an elastic-plastic series experiment, and a viscous-plastic series experiment, and any combination thereof; The parallel dual-mode experiment includes one of an elastic-viscous parallel experiment, an elastic-plastic parallel experiment, and a viscous-plastic parallel experiment, and any combination thereof.

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