Material mechanics stress state demonstration teaching aid

Abstract

The utility model provides a material mechanics stress state demonstration teaching aid comprising a solid flexible cylinder, and the surface of the flexible cylinder is provided with a plurality of first marking lines and a plurality of second marking lines; wherein the first marking lines extend in the length direction of the flexible column body, and the multiple first marking lines are arranged around the circumferential direction of the flexible column body at equal intervals; the second marking lines are arranged in the circumferential direction of the flexible column body, and the multiple second marking lines are arranged at equal intervals in the length direction of the flexible column body. The material mechanics stress state demonstration teaching aid provided by the utility model can be used for demonstrating basic deformation in material mechanics, such as stretching, compression, shearing, torsion, bending and the like, and can visually display the deformation condition inside a material to students, so that the students can better understand the concept of a stress unit body; students are helped to correctly and quickly judge the stress state of each point of the cross section of the rod piece in various basic deformations.

Description

Technical Field

[0001] The utility model relates to the technical field of teaching aids, in particular to a material mechanics stress state demonstration teaching aid. Background Art

[0002] In the material mechanics teaching course, students generally learn five basic deformations: tension, compression, shear, torsion, and bending, as well as their combined deformations. The strength verification of combined deformation of rods is a difficult point in the teaching course, and mastering the stress state changes of rods facilitates the understanding of the strength verification of rod deformation in subsequent teaching.

[0003] At present, in the teaching course of material mechanics, teachers generally use PPT demonstration combined with text description to explain the stress state of various rod deformations. Students will find it abstract and difficult to understand during the learning process, and often have problems understanding the stress unit and judging the stress direction. However, the existing teaching aids do not have the function of demonstrating the internal stress state of the rod, and cannot help students understand the deformation and stress state inside the rod. Utility Model Content

[0004] In view of this, the purpose of the utility model is to provide a material mechanics stress state demonstration teaching aid to solve the problem in the prior art that the teaching content of the change of the deformation stress state of a rod is not easy to understand.

[0005] Based on the above purpose, the utility model provides a material mechanics stress state demonstration teaching aid, including:

[0006] A solid flexible column, wherein a plurality of first marking lines and a plurality of second marking lines are provided on a surface of the flexible column;

[0007] The first marking line extends along the length direction of the flexible column, and a plurality of the first marking lines are arranged at equal intervals around the circumference of the flexible column; the second marking line is arranged around the circumference of the flexible column, and a plurality of the second marking lines are arranged at equal intervals along the length direction of the flexible column.

[0008] Furthermore, grooves are formed in the surface area of ​​the flexible column corresponding to the first marking line and the second marking line, and the groove widths of the grooves corresponding to the first marking line and the second marking line are 1-2 times of the groove depths.

[0009] Furthermore, the flexible column is formed by connecting at least two flexible short rods, each of the flexible short rods has the same diameter, and the flexible short rods are detachably connected.

[0010] Furthermore, the butt joint end of one of the flexible columns is provided with at least two hook connectors, and the butt joint end of the other flexible column is provided with a slot extending in a radial direction, and when the two flexible columns are butt jointed, the hook connectors are inserted into the slots.

[0011] Furthermore, the hook connector includes a first connecting portion protruding along the axial direction of the flexible column, and a second connecting portion bent relative to the first connecting portion, and the second connecting portion is configured to be inserted into the slot.

[0012] Furthermore, a plurality of mounting grooves are provided at the side ends of the flexible column, and demonstration blocks are detachably installed in the mounting grooves, and the size specifications of the plurality of demonstration blocks are the same.

[0013] Furthermore, the plurality of mounting grooves are evenly distributed on the side ends of the flexible column, and the demonstration block is a regular rectangular block or a sphere.

[0014] Furthermore, one of the mounting grooves is located on the axis of the flexible column.

[0015] Furthermore, the demonstration block is a cube block.

[0016] Furthermore, the flexible column is made of rubber material.

[0017] From the above description, it can be seen that the material mechanics stress state demonstration teaching aid provided by the utility model uses a first marking line and a second marking line to be set on a solid flexible column. When the flexible column is deformed under force, the first marking line and the second marking line on the column will also be synchronously offset, thereby facilitating students to more intuitively observe the stress deformation state of the main body and helping students to correctly and quickly judge the stress distribution of the rod during various basic deformation processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 This is a schematic diagram of the overall structure of the flexible column in the embodiment of the utility model;

[0020] Figure 2 This is a schematic diagram of the butt joint surface of the flexible short rod in the embodiment of the utility model;

[0021] Figure 3 This is a cutaway view of a slot in a flexible short rod in an embodiment of the utility model;

[0022] Figure 4 It is a schematic diagram of an exemplary structure of a hook connector in an embodiment of the utility model.

[0023] Description of the accompanying drawings

[0024] 1. Flexible column; 2. First flexible short rod; 3. Second flexible short rod; 4. Third flexible short rod; 5. Hook connector; 51. First connecting portion; 52. Second connecting portion; 6. Cube block; 7. Slot; 81. First marking line; 82. Second marking line. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0026] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the utility model should be the common meanings understood by people with ordinary skills in the field to which the disclosure belongs. The "first", "second" and similar words used in the present disclosure do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] One or more embodiments of the present application provide a material mechanical stress state demonstration teaching aid, which is described below in conjunction with the accompanying drawings.

[0028] like Figure 1 As shown, the material mechanical stress state demonstration teaching aid includes a solid flexible column 1, and a plurality of first marking lines 81 and a plurality of second marking lines 82 are provided on the surface of the flexible column 1; wherein, the first marking lines 81 extend along the length direction of the flexible column 1, and the plurality of first marking lines 81 are arranged at equal intervals around the circumference of the flexible column 1; the second marking lines 82 are arranged around the circumference of the flexible column 1, and the plurality of second marking lines 82 are arranged at equal intervals along the length direction of the flexible column 1.

[0029] From the above description, it can be seen that the material mechanics stress state demonstration teaching aids described in the present application use a first marking line 81 and a second marking line 82 to be set on a solid flexible column 1. When the flexible column 1 is deformed by force, the first marking line 81 and the second marking line 82 located on the column will also be synchronously offset, thereby facilitating students to more intuitively observe the force and deformation state of the main body, and helping students to correctly and quickly judge the stress distribution of the rod during various basic deformation processes.

[0030] like Figure 1 As shown, the flexible column 1 can be made of rubber material, such as fluororubber, propylene rubber or silicone rubber, as long as it has excellent deformation characteristics and elastic properties. The surface area of ​​the flexible column 1 corresponding to the first marking line 81 and the second marking line 82 is provided with grooves, and the groove width corresponding to the first marking line 81 and the second marking line 82 is 1-2 times the groove depth. Here, the flexible column 1 is placed horizontally as the reference direction, the first marking line 81 is the horizontal marking line, the second marking line 82 is the longitudinal marking line, and the area formed by the intersection of the first marking line 81 and the second marking line 82 is a rectangular area arranged in an array.

[0031] In the above description, the groove width and groove depth of the groove corresponding to the first marking line 81 and the second marking line 82 can be the same, or the groove width can be greater than the groove depth. For example, the groove width is 1.5 times or 2 times the groove depth.

[0032] In the above embodiment, the first marking line 81 and the second marking line 82 can be marked with eye-catching color lines to facilitate students to observe the line changes intuitively and carefully, wherein the first marking line 81 corresponds to the center line of the groove, and the second marking line 82 corresponds to the center line of the groove. During the force deformation process of the flexible column 1, the set groove can reveal the deformation position to a large extent and provide a deformation buffer space, so that the deformation of the flexible column 1 is more intuitive and clear, and easy to observe and understand.

[0033] In some embodiments, Figure 2 As shown, the flexible column 1 is formed by the butt joint of at least two flexible short rods, each of which has the same diameter, and the flexible short rods are detachably butt jointed.

[0034] Exemplarily, the flexible column 1 is composed of three flexible short rods, namely a first flexible short rod 2, a second flexible short rod 3 and a third flexible short rod 4, wherein the three flexible short rods are connected end to end in pairs, wherein the three flexible short rods have the same diameter, and their butt ends are butt-jointed through surface contact to form a complete flexible column 1.

[0035] Here, taking the connection process of the first flexible short rod 2 and the second flexible short rod 3 as an example, at least two hook connectors 5 are provided at the docking end of the first flexible short rod 2 facing the second flexible short rod 3, and the second flexible column 1 is provided with a slot 7 extending in a radial direction at the docking end of the first flexible short rod 2. When the two flexible columns 1 are docked, the hook connector 5 is inserted into the slot 7.

[0036] The hook connector 5 includes a first connection portion 51 protruding along the axial direction of the flexible column 1, and a second connection portion 52 bent relative to the first connection portion 51, and the second connection portion 52 is configured to be inserted into the slot 7. Here, the hook connector 5 is fixedly connected to the side wall of the first flexible short rod 2, and when the second connection portion 52 of the hook connector 5 is inserted into the slot 7, the connection end of the hook connector 5 and the first flexible short rod 2 will be slightly deformed to adapt to the insertion of the second connection portion 52 into the slot 7.

[0037] like Figure 3 As shown, Figure 3 Schematic diagram of the cross section of the slot 7 of the second flexible short rod 3. For example, the slot 7 extends inwardly along the radial direction of the second flexible short rod 3, and the slot depth of the slot 7 is slightly smaller than the radius of the second flexible short rod 3, thereby ensuring the second connection portion 52 is inserted into the slot 7. The second flexible column 1 has four evenly distributed slots 7. Of course, the number of the hook connectors 5 can be flexibly set.

[0038] It should be noted that the hook connector 5 can be integrally formed with the first flexible short rod 2, or fixed by gluing, and the connecting end of the hook connector 5 and the first flexible short rod 2 is parallel to or coincides with the first marking line 81 to minimize the impact of the hook connector 5 on the deformation of the flexible short rod.

[0039] In the above embodiment, a hook connector 5 is provided at one end of the first flexible short rod 2, and a slot 7 is provided at the other end. Similarly, a hook connector 5 is provided at one end of the second flexible short rod 3, and a slot 7 is provided at the other end. The slot 7 of the first flexible short rod 2 and the hook connector 5 of other flexible short rods are connected to form a fixation. The hook connector 5 of the first flexible short rod 2 is hooked with the slot 7 of the second flexible short rod 3 to form a fixation, thereby forming a flexible column 1.

[0040] As an alternative embodiment, the hook connector 5 may also be an independent connector, such as Figure 4As shown, the hook connector 5 is in the shape of a "door", and slots 7 extending inward in the radial direction are respectively provided on the side walls of the first flexible short rod 2 and the second flexible short rod 3. The two ends of the hook connector 5 are respectively inserted into the slots 7, and the first flexible short rod 2 and the second flexible short rod 3 are connected by using the bent hook characteristics. When disassembling, the hook connector 5 can be removed by pulling it outward in the radial direction of any flexible short rod, which is convenient and quick, and at the same time, it does not affect the teaching experiment process of tensile deformation and compression deformation.

[0041] In the above embodiment, when the hook connector 5 is an independent connector, the length of the lateral portion of the hook connector 5 is equal to the sum of the lengths of the two rectangular areas. Thus, the insertion point of the second connecting portion 52 of the hook connector 5 is located at the intersection of the first marking line 81 and the second marking line 82 of any flexible short rod, thereby avoiding affecting the observed stress change state and ensuring that the flexible short rod is evenly stressed.

[0042] In some embodiments, Figure 2 As shown, a plurality of mounting grooves are provided at the side ends of the flexible column 1, and demonstration blocks are detachably installed in the mounting grooves, and the size specifications of the plurality of demonstration blocks are the same.

[0043] In the above embodiment, the plurality of mounting grooves are evenly distributed on the side ends of the flexible column 1, and the demonstration block is a regular rectangular block or a sphere. Figure 2 The cube block 6 shown is used as a demonstration block to explain the stress distribution points inside the flexible column 1, so that it is easy for students to understand the internal stress distribution of the flexible column 1. In addition, one of the mounting grooves is located on the axis of the flexible column 1. Therefore, the demonstration block located on the axis of the flexible column 1 is used as a demonstration block on the center line, and multiple demonstration blocks at different positions can facilitate the explanation of the stress distribution at different positions inside the flexible column 1, so as to facilitate students' understanding.

[0044] An exemplary use process of the material mechanics stress state demonstration teaching aid described in this application is as follows:

[0045] Teaching experiment 1: Explore the stress state of a rod during tensile deformation.

[0046] Hold the two ends of the flexible column 1 with both hands, apply tension along the axis direction of the flexible column 1, and students can see the deformation phenomenon of the outside of the flexible column 1, observe the changes of the first marking line 81 and the second marking line 82, remove the hook connector 5 on any flexible short rod to be studied, and the five cube blocks 6 at different positions represent the stress unit bodies at their corresponding positions. First, demonstrate the tensile deformation on the flexible short rod to be studied, and then demonstrate the stress state of the point through the cube block 6. The same is true for the compression deformation of the rod.

[0047] Teaching Experiment 2: Explore the stress state of a rod during shear deformation.

[0048] Hold the flexible short rod tightly with both hands at any connection position, and apply external force in opposite directions perpendicular to the axis of the flexible column 1. Students can see the deformation phenomenon on the outside of the flexible column 1 and observe the changes of the first marking line 81 and the second marking line 82. Remove the hook connector 5 of the flexible short rod under study. The cube blocks 6 at the five positions represent the stress unit bodies at their locations. First demonstrate the shear deformation on the flexible short rod to be studied, and then demonstrate the stress state of the point through the cube block 6.

[0049] Teaching Experiment 3: Explore the stress state of a rod during torsional deformation.

[0050] Hold the two ends of the flexible column 1 with both hands, and apply an external force couple with the action surface perpendicular to the axis of the flexible column 1 and in the opposite direction. Students can see the deformation phenomenon on the outside of the flexible column 1 and observe the changes of the first marking line 81 and the second marking line 82. Remove the hook connector 5 on any flexible short rod to be studied. The cube blocks 6 at the five positions represent the stress unit bodies at their locations. First, simulate the tensile deformation on the flexible short rod to be studied, and then demonstrate the stress state of the point through the cube block 6.

[0051] Teaching Experiment 4: Explore the stress state of a rod during bending deformation.

[0052] Hold the two ends of the flexible column 1 with both hands, and apply external force couples in opposite directions within the longitudinal symmetry plane of the flexible column 1. Students can see the deformation phenomenon on the outside of the flexible column 1 and observe the changes in the first marking line 81 and the second marking line 82. Remove the hook connector 5 on any flexible short rod to be studied. The cube blocks 6 at the five positions represent the stress unit bodies at their points. First, demonstrate the bending deformation on the flexible short rod to be studied, and then demonstrate the stress state of the point through the cube block 6. If you want to study the deformation of the midpoint of the rod, you can select any two adjacent flexible short rods, such as the first flexible short rod 2 and the second flexible short rod 3, or the second flexible short rod 3 and the third flexible short rod 4.

[0053] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0054] The embodiments of the present invention are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A material mechanics stress state demonstration teaching aid, characterized in that: include: A solid flexible column, wherein a plurality of first marking lines and a plurality of second marking lines are provided on a surface of the flexible column; The first marking line extends along the length direction of the flexible column, and a plurality of the first marking lines are arranged at equal intervals around the circumference of the flexible column; the second marking line is arranged around the circumference of the flexible column, and a plurality of the second marking lines are arranged at equal intervals along the length direction of the flexible column.

2. The material mechanics stress state demonstration teaching aid according to claim 1, characterized in that: Grooves are formed on the surface of the flexible column corresponding to the first marking line and the second marking line, and the width of the grooves corresponding to the first marking line and the second marking line is 1-2 times of the groove depth.

3. The material mechanics stress state demonstration teaching aid according to claim 1, characterized in that: The flexible column is formed by the butt joint of at least two flexible short rods, each of the flexible short rods has the same diameter, and the flexible short rods are detachably butt jointed.

4. The material mechanics stress state demonstration teaching aid according to claim 3, characterized in that: The butt joint end of one of the flexible columns is provided with at least two hook connectors, and the butt joint end of the other flexible column is provided with a slot extending in a radial direction. When the two flexible columns are butt jointed, the hook connectors are inserted into the slots.

5. The material mechanics stress state demonstration teaching aid according to claim 4, characterized in that: The hook connector includes a first connecting portion protruding along the axial direction of the flexible column, and a second connecting portion bent relative to the first connecting portion, wherein the second connecting portion is configured to be inserted into the slot.

6. The material mechanics stress state demonstration teaching aid according to claim 1, characterized in that: A plurality of mounting grooves are provided at the side ends of the flexible column, and demonstration blocks are detachably mounted in the mounting grooves, and the size specifications of the plurality of demonstration blocks are the same.

7. The material mechanics stress state demonstration teaching aid according to claim 6, characterized in that: A plurality of the mounting grooves are evenly distributed on the side ends of the flexible column, and the demonstration block is a regular rectangular block or a sphere.

8. The material mechanics stress state demonstration teaching aid according to claim 7, characterized in that: One of the mounting grooves is located on the axis of the flexible column.

9. The material mechanics stress state demonstration teaching aid according to claim 7, characterized in that: The demonstration block is a cube block.

10. The material mechanics stress state demonstration teaching aid according to claim 1, characterized in that: The flexible column is made of rubber material.

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