Mechanical state reconstruction method and teaching aid driven by discrete strain

Abstract

The present application relates to the technical field of engineering mechanics teaching and experimental equipment, and discloses a method for reconstructing mechanical state driven by discrete strain and a teaching aid, wherein the teaching aid comprises a plurality of structural members provided with member identity marks and strain sensors, a plurality of node connectors provided with node identity marks, a data acquisition unit, and a data processing and display unit. The data processing and display unit determines a target structural system according to the member identity marks, the node identity marks, and the connection relationship between the members and the nodes, reconstructs axial force, bending moment, and shear force according to the discrete strain signals, and further obtains the structural deformation state by performing consistency check in combination with the structural balance relationship. The present application can display the axial force distribution, the shear force distribution, the bending moment distribution, and the deformation state of the structure in real time, so that the experimental measurement results are clearly corresponding to the theoretical analysis of material mechanics and structural mechanics.

Description

Technical Field

[0001] This invention relates to the field of teaching and experimental equipment technology in engineering mechanics, and in particular to a discrete strain-driven mechanical state reconstruction method and teaching aid. Background Technology

[0002] In teaching mechanics of materials and structural mechanics, students not only need to master basic concepts such as bending moment, shear force, and axial force, but also need to understand the correspondence between the distribution of internal forces and the deformation state of a structure under load. Current classroom teaching typically focuses on formula derivation, force analysis, and static diagrams, making it difficult for students to establish a continuous and intuitive connection between load action, changes in internal forces, and the structural deformation process. For beginners, internal force diagrams and deflection curves often remain at the level of theoretical derivation and paper representation, lacking a clear understanding of the formation and evolution of the structural stress state.

[0003] Currently, some universities use strain gauges glued to the surface of structural components to obtain strain data in experimental teaching, and then analyze the stress characteristics of the structure based on this data. While this method can obtain measured data, it usually requires repeated gating, wiring, debugging, and calibration of strain gauges before each experiment, resulting in a lot of preparation work and low experimental efficiency. In addition, strain measurement results usually correspond to only a few discrete measurement points, and students obtain a few discrete strain values. The complete internal force distribution diagram and deformation curve still need to be processed through subsequent theoretical derivation, manual calculation, or other software, making it difficult to directly present the overall stress state of the structure during loading.

[0004] Existing teaching experiments typically revolve around a single specimen, with relatively fixed structural forms, connection methods, and boundary conditions, making rapid adjustments difficult. For different structural systems such as simply supported beams, continuous beams, and rigid frames, it is usually necessary to replace the entire set of specimens or rearrange the measuring points and connection lines, making it difficult to achieve rapid switching and continuous comparison of different structural systems on the same teaching platform. Experimental data is usually organized according to the method of applying loads, recording data, and processing it after class. Students find it difficult to observe the synchronous evolution of internal force distribution, deformation curves, and support responses while the structure is under stress, limiting the effectiveness of dynamic teaching.

[0005] Some existing modular teaching aids can demonstrate the assembly relationship between structural components and node connectors, facilitating the explanation of the composition of structural components, nodes, and supports. However, most modular teaching aids are mainly used for structural morphology demonstration and are difficult to realize real-time measurement, calculation, and graphical display of structural mechanical response. Although professional finite element software can calculate and visualize structural response, its modeling, solving, and post-processing processes are relatively abstract for beginners, making it difficult for students to directly understand the derivation relationships between measured strain and stress, internal force distribution, and deformation state.

[0006] Therefore, a demonstration system for teaching engineering mechanics is needed. This system should be able to adapt to rapid assembly of different structural systems and different connection forms and support constraints. It should be able to reconstruct the internal force distribution and deformation state of the structure based on discrete strain measurement results, and display the load changes, discrete strain response, internal force distribution and deformation state in a real-time, intuitive and easy-to-understand manner. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems existing in the teaching and experimental equipment of engineering mechanics, such as cumbersome experimental preparation process, measurement results corresponding to only a small number of discrete measurement points, difficulty in presenting the distribution of internal forces and deformation state of the structure in real time and intuitively, inconvenience in switching between different structural systems and different connection constraints, and the disconnect between experimental measurement results and the theoretical analysis process of mechanics of materials and structural mechanics. This invention provides a discrete strain-driven mechanical state reconstruction method and teaching aid.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A discrete strain-driven mechanical state reconstruction teaching tool includes: multiple structural components, each of which is provided with a component identification mark and a strain sensor located at multiple measuring point sections, wherein the strain sensor is provided on both sides of the neutral axis of each of the measuring point sections used to reconstruct axial force and bending moment;

[0010] The connection relationship acquisition unit is communicatively connected to the data processing and display unit and is used to acquire the connection correspondence between the ends of each structural component and each node connector.

[0011] A data acquisition unit, connected to the strain sensor, is used to acquire the discrete strain signal output by the strain sensor;

[0012] The data processing and display unit, which is communicatively connected to the data acquisition unit, is used for:

[0013] Component parameters and measurement point location information are obtained based on the component identification, node connection form, connection degree of freedom and support constraint conditions are obtained based on the node identification, and a structural topology model of the target structural system is established based on the connection correspondence to determine the structural system type of the target structural system;

[0014] Based on the discrete strain signal and the component parameters, the axial force and bending moment of each measuring point section are reconstructed, and the shear force is obtained based on the reconstructed bending moment value of adjacent measuring point sections.

[0015] Based on the structural system type, the node connection form, and the support constraint conditions, an overall static equilibrium relationship is established, and the consistency of the reconstructed axial force, bending moment, and shear force is verified.

[0016] A continuous bending moment function is constructed based on the reconstructed bending moment values ​​of each measuring point section after consistency verification. The deformation state of the target structural system is then reconstructed based on the continuous bending moment function, the component parameters, the node connection type, the connection degrees of freedom, and the support constraints.

[0017] The system graphically displays in real time the axial force distribution, shear force distribution, bending moment distribution, and deformation state of the target structural system.

[0018] Preferably, each of the structural components adopts a uniform cross-sectional shape and is configured with different length specifications according to the target structural system;

[0019] The measuring point section includes at least one of the mid-span section, the quarter-point section, and the near-end measuring point section close to the end of the structural member;

[0020] The measuring section used to identify shear force is also equipped with an oblique strain sensor or strain rosette.

[0021] Preferably, each of the structural components includes a rod body, a sensor packaging area, a wire channel, and an identification tag installation area;

[0022] The sensor encapsulation area is a shallow groove on the surface of the rod body, an embedded groove inside the rod body, or a thin-walled encapsulation area on the rod body. The strain sensor is encapsulated in the sensor encapsulation area, and the sensitive grid direction of the strain sensor is consistent with the axial direction or predetermined measurement direction of the rod body.

[0023] The wire channel is set along the length of the main body of the rod or a reserved path inside the main body of the rod, and is used to arrange the wires connecting the strain sensor and the data acquisition unit;

[0024] A protective layer is provided on the outside of the sensor packaging area. The protective layer is used to protect the strain sensor and maintain the deformation transmission relationship between the strain sensor and the main body of the rod.

[0025] Preferably, the structural member includes a hinged member and a fixed member, wherein the hinged member and the fixed member each have an end connection structure integrally formed with the end of the corresponding member;

[0026] The end of the hinge member is provided with an ear plate and a pin hole. The node connector includes a hinge node. The hinge node is provided with a connecting part that cooperates with the ear plate. The pin passes through the pin hole and the connecting part so that the hinge member is rotatably connected to the hinge node.

[0027] The end of the fixed rod is provided with a rectangular end, and the node connector also includes a fixed node. The fixed node is provided with a rectangular insertion cavity that mates with the rectangular end. After the rectangular end is inserted into the rectangular insertion cavity, the fixed rod is restricted from axially disengaging by a limiting member, and the fixed rod is restricted from rotating relative to the fixed node by a rigid rotation limiting sleeve or rigid covering structure disposed outside the insertion area formed by the rectangular end and the rectangular insertion cavity.

[0028] The limiting component is a limiting pin or a limiting pin block;

[0029] The node connector also includes a hinged support node and a fixed support node. The hinged support node is formed by combining the hinged node with the base plate, and the fixed support node is formed by combining the fixed node with the base plate.

[0030] Preferably, the data acquisition unit is also connected to at least one of the loading measuring device and the support measuring device;

[0031] The loading measurement device is used to provide external load information to the data acquisition unit, and the support measurement device is used to provide support reaction force information to the data acquisition unit.

[0032] A discrete strain-driven mechanical state reconstruction method includes:

[0033] Multiple structural components are assembled into a target structural system through multiple node connectors, and the connection correspondence between the ends of each structural component and each node connector is obtained;

[0034] Read the component identification and the node identification to obtain component parameters, measurement point location information, node connection type, connection degree of freedom and support constraint conditions;

[0035] Based on the connection correspondence, establish the structural topology model of the target structural system and determine the structural system type of the target structural system;

[0036] Collect the discrete strain signals output by the strain sensor;

[0037] Based on the discrete strain signal and the component parameters, the axial force and bending moment of each measuring point section are reconstructed, and the shear force is obtained based on the reconstructed bending moment value of adjacent measuring point sections.

[0038] Based on the structural topology model, structural system type, node connection form, external load information, and support constraint conditions, an overall static equilibrium relationship is established, and the consistency of the reconstructed axial force, bending moment, and shear force is verified.

[0039] A continuous bending moment function is constructed based on the reconstructed bending moment values ​​of each measuring point section after consistency verification. The deformation state of the target structural system is then reconstructed based on the continuous bending moment function, the component parameters, the node connection type, the connection degrees of freedom, and the support constraints.

[0040] The system graphically displays in real time the axial force distribution, shear force distribution, bending moment distribution, and deformation state of the target structural system.

[0041] Preferably, the axial average strain of the cross-section at the measuring point is calculated based on the discrete strain signals output by the strain sensors located on both sides of the neutral axis of the same measuring point cross-section. and cross-sectional curvature ;

[0042] The cross-sectional area of ​​the measuring point is retrieved based on the component's identification. Moment of inertia of cross section and the elastic modulus of the structural member where the measuring point section is located The axial force at the measuring point section is calculated according to the following formula. and bending moment :

[0043] ;

[0044] .

[0045] Preferably, the bending moment reconstruction values ​​of adjacent measuring point sections are differentially analyzed to obtain the estimated shear force value, and the estimated shear force value is corrected based on at least one of the strain information collected by the oblique strain measuring point, the strain information collected by the strain rosette, the obtained external load information, and the obtained support reaction force information.

[0046] For the near-end measuring point section close to the end of the structural member, based on the axial force, bending moment and shear force of the near-end measuring point section, combined with the geometric positional relationship between the near-end measuring point section and the corresponding node connector and the known load conditions, the end force of the structural member is converted or estimated.

[0047] When the result of the consistency verification does not meet the preset error criterion, the interpolation result of the internal force of the adjacent measuring point section or the estimation result of the internal force of the rod end is corrected according to at least one of the external load information and the support reaction force information.

[0048] When the target structural system is a statically indeterminate structure, an overall static equilibrium relationship is established based on the structural topology model, external load information, and support constraint conditions, and a deformation coordination relationship is established based on the component parameters, node displacement continuity conditions, and node rotation coordination conditions. The internal forces of the measuring point sections obtained based on the discrete strain signals are used as observation constraints and are solved jointly with the overall static equilibrium relationship and the deformation coordination relationship to obtain the redundant constraint forces or redundant internal forces of the target structural system.

[0049] Preferably, when establishing the continuous bending moment function, the segmented control position is determined based on the known load type, load application location, node location, component end location, and the variation characteristics of the bending moment reconstruction value of adjacent measuring point sections;

[0050] When the structural member is subjected to a concentrated force, the position of the concentrated force, the position of the node, and the position of the end of the member are used as the segmented control positions. A segmented bending moment function is established in each segment using a linear function or a low-order polynomial, and a bending moment continuity condition is applied at the position of the concentrated force.

[0051] When the structural member is subjected to a concentrated moment, a bending moment abrupt change condition is applied at the location where the concentrated moment is applied.

[0052] When the structural member is subjected to a uniformly distributed load, a quadratic polynomial is used to establish the bending moment function of the corresponding section.

[0053] The undetermined parameters in the piecewise bending moment function are determined based on the reconstructed bending moment values ​​at each measuring point section, the end boundary conditions, and the nodal equilibrium conditions.

[0054] When the target structural system is a beam structure, the continuous bending moment function is denoted as... and the continuous bending moment function Substituting into the differential equation of the beam deflection curve:

[0055]

[0056] in, For deflection function, Let be the flexural stiffness of the cross section of the corresponding structural member whose deformation is to be solved;

[0057] The differential equation of the beam deflection curve is integrated twice, and the integration constant is solved based on the boundary conditions determined by the support constraints. When the beam structure is a continuous beam, the integration constant is also solved in combination with the continuous conditions of span displacement and span rotation, so as to obtain the continuous deflection curve of the beam structure.

[0058] Preferably, when the target structural system is a rigid frame or other multi-member structure, a continuous bending moment function for each structural member in the local coordinate system is established respectively;

[0059] Based on the nodal displacement continuity condition, nodal rotation coordination condition, the support constraint condition, and the transformation relationship between the local coordinate system and the global coordinate system, establish the overall deformation coordination equation or equivalent structural matrix equation of the target structural system.

[0060] The overall deformation state of the target structural system is solved based on the overall deformation compatibility equation or the equivalent structural matrix equation.

[0061] The beneficial effects of this invention are as follows:

[0062] This invention is based on discrete strain signals output by strain sensors installed at multiple measuring points on structural components. It combines Hooke's law, cross-sectional force relationships, overall static equilibrium relationships, and deformation compatibility conditions to progressively reconstruct the axial force, bending moment, shear force, and deformation state of the target structural system. Compared to traditional experimental methods that only display strain values ​​at measuring points, this invention can further convert discrete strain signals into axial force distribution, shear force distribution, bending moment distribution, and deformation state, and display them graphically in real time. This allows for a clearer correspondence between experimental measurement results and the fundamental theories of mechanics of materials and structural mechanics.

[0063] This invention enables the conversion from discrete measurement results to a continuous mechanical state. The data processing and display unit reconstructs the axial force and bending moment of the corresponding measuring point section based on the discrete strain signals of each measuring point section, and obtains the shear force based on the reconstructed bending moment values ​​of adjacent measuring point sections. After verifying the consistency of the reconstructed axial force, bending moment, and shear force, a continuous bending moment function is constructed based on the reconstructed bending moment values ​​of each measuring point section, and the deformation state of the target structural system is further reconstructed. Thus, the structural stress state can be transformed from discrete measuring point data into a continuous internal force distribution and deformation state, which is displayed synchronously during loading, facilitating the observation of the real-time relationship between load changes, measuring point responses, internal force distribution, and deformation state.

[0064] This invention employs modular structural components and node connectors, each with its own component and node identification identifier. The data processing and display unit reads these identifiers to obtain component parameters, measurement point locations, node connection types, connection degrees of freedom, and support constraints. It then determines the structural system type of the target structure, enabling automatic adaptation to the corresponding mechanical state reconstruction process based on the currently assembled target structural system. By changing the structural components and node connectors, the same set of teaching aids can be used to form different structural systems such as simply supported beams, continuous beams, and rigid frames, facilitating rapid switching and comparative demonstrations between different structural systems.

[0065] The structural components of this invention include hinged members and fixed members, each having an end connection structure integrally formed with the corresponding end of the member. The hinged member is rotatably connected to the hinged node via an ear plate, a pin hole, and a pin shaft. After the rectangular end of the fixed member is inserted into the rectangular insertion cavity of the fixed node, a limiting member restricts the fixed member from axially disengaging it, and a rigid rotation-limiting sleeve or rigid covering structure located outside the insertion area restricts the fixed member's rotation relative to the fixed node. The above-mentioned node connection forms are clear, the fit between the structural components and the node connectors is intuitive, facilitating the assembly of different target structural systems, and enabling demonstrations of the influence of node connection forms, connection degrees of freedom, and support constraints on the distribution of internal forces and deformation states of the structure.

[0066] This invention pre-encapsulates the strain sensor within the sensor enclosure area of ​​a structural component, and connects the strain sensor to the data acquisition unit via a wire channel. During experiments, there is no need to repeatedly attach strain sensors and perform large-scale on-site wiring for different target structural systems. Different structural systems can be assembled and compared by replacing structural components, node connectors, and support nodes, which improves the reusability of the teaching aid and reduces experimental preparation work. Attached Figure Description

[0067] Figure 1 This is a schematic diagram of the overall system structure of the discrete strain-driven mechanical state reconstruction teaching aid described in an embodiment of the present invention;

[0068] Figure 2 This is a schematic diagram illustrating the connection between the node connector and the structural member according to an embodiment of the present invention, wherein, Figure 2 (a) is a schematic diagram of the connection between the hinged member and the hinged node. Figure 2 (b) is a schematic diagram of the connection between the fixed member and the fixed node;

[0069] Figure 3 This is a schematic diagram of the measuring point cross section and strain sensor arrangement of the structural component described in an embodiment of the present invention;

[0070] Figure 4 This is a flowchart illustrating the discrete strain-driven mechanical state reconstruction method according to an embodiment of the present invention.

[0071] Figure 5 This is a schematic diagram illustrating the assembly and mechanical state reconstruction of a typical target structural system according to an embodiment of the present invention, wherein, Figure 5 (a) is a schematic diagram of the assembly and mechanical state reconstruction of a simply supported beam. Figure 5 (b) is a schematic diagram of the assembly and mechanical state reconstruction of the continuous beam. Figure 5 (c) is a schematic diagram of the assembly and mechanical state reconstruction of the rigid frame.

[0072] In the diagram: 100 - Standardized structural components; 110 - Strain sensors; 130 - Component identification; 200 - Node connectors; 300 - Data acquisition boxes; 400 - Tablet PCs. Detailed Implementation

[0073] To provide a clearer understanding of the technical features, objectives, and beneficial effects of this invention, the technical solution of this invention is described in detail below, but this should not be construed as limiting the scope of implementation of this invention. Unless otherwise specified, the methods used in this invention are conventional methods in this technical field. In this invention, materials, reagents, or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0074] In one embodiment, such as Figures 1 to 4 As shown, the discrete strain-driven mechanical state reconstruction teaching aid of the present invention includes multiple structural components, multiple node connectors, a connection relationship acquisition unit, a data acquisition unit, and a data processing and display unit. Each structural component is equipped with a component identification mark and a strain sensor located at multiple measuring point sections, and each node connector is equipped with a node identification mark. The connection relationship acquisition unit is used to acquire the connection correspondence between the ends of each structural component and each node connector. The data acquisition unit is used to acquire discrete strain signals. The data processing and display unit establishes a structural topology model of the target structural system based on the component identification mark, node identification mark, and connection correspondence, and completes the internal force reconstruction at the measuring point sections, consistency verification, continuous bending moment function construction, deformation state reconstruction, and real-time graphical display.

[0075] In this embodiment, the structural components are standardized structural components, which can adopt a uniform cross-sectional shape and be set to different length specifications according to teaching needs and the target structural system, so as to assemble different load-bearing components such as beams, columns, and diagonal braces. Each structural component includes a rod body, an end connection structure, a sensor encapsulation area, a wire channel, and an identification label installation area. The sensor encapsulation area can be a shallow groove on the surface of the rod body, an embedded groove inside the rod body, or a thin-walled encapsulation area on the rod body; the strain sensor is encapsulated in the sensor encapsulation area, and its sensitive grid direction is consistent with the axial direction of the rod body or the predetermined measurement direction. The wire channel is used to arrange the wires connecting the strain sensor and the data acquisition unit. A protective layer is provided on the outside of the sensor encapsulation area to protect the strain sensor and maintain the deformation transmission relationship between the strain sensor and the rod body.

[0076] The component identification corresponds to the component parameter library. The data processing and display unit retrieves the component length, cross-sectional area, moment of inertia, elastic modulus, number of measuring points, position of measuring points, and distance from the measuring point to the neutral axis of the corresponding measuring point cross section based on the component identification. The end connection structure of the structural component is integrally formed with the end of the corresponding rod. Specifically, the lug and pin hole of the hinged rod are integrally formed or integrally machined with the main body of the corresponding rod, and the rectangular end of the fixed rod is integrally formed or integrally machined with the main body of the corresponding rod.

[0077] The node connectors are used to connect the structural components and include hinged nodes, fixed nodes, hinged support nodes, and fixed support nodes. Each node connector is provided with a node identification identifier, which is associated with the node type, connection degree of freedom, constraint direction, support form, and boundary conditions. The data processing and display unit obtains the node connection form, connection degree of freedom, and support constraint conditions based on the node identification identifier.

[0078] The connection relationship acquisition unit is used to acquire the connection correspondence between the ends of each structural member and each node connector. The connection correspondence is used to characterize the node connectors connected to each end of each structural member, and the structural members connected to the same node connector.

[0079] The data processing and display unit establishes a structural topology model of the target structural system based on the connection correspondence. The structural topology model represents the connection relationships between each structural component, each node connector, and each support node. The data processing and display unit, combining the structural topology model, component identifiers, and node identifiers, determines the structural system type of the target structural system.

[0080] The node identification can employ one or more of the following: resistive coding, memory chip coding, RFID tags, magnetic identification structures, socket coding structures, or mechanical key identification structures. For example... Figure 2 As shown in (a), the lug at the end of the hinge member is rotatably connected to the connection of the hinge node via a pin, so as to allow the end of the hinge member to rotate relative to the hinge node.

[0081] like Figure 2 As shown in (b), after the rectangular end of the fixed member is inserted into the rectangular insertion cavity of the fixed node, the fixed member is restricted from axially disengaging by a limiting pin or limiting pin block, and the fixed member is restricted from rotating relative to the fixed node by a rigid rotation-limiting sleeve or rigid covering structure disposed outside the insertion area. The hinge support node is formed by combining the hinge node and the base plate, and the fixed support node is formed by combining the fixed node and the base plate.

[0082] The data acquisition unit is connected to the strain sensor to acquire discrete strain signals during the loading process, and can be connected to at least one of the loading measurement device and the support measurement device to obtain external load information or support reaction force information.

[0083] The data processing and display unit is communicatively connected to the data acquisition unit and may include a component parameter calling module, a node constraint identification module, a structural topology modeling module, a strain data processing module, a section internal force reconstruction module, a shear force estimation and correction module, a rod end internal force estimation module, an overall equilibrium verification module, a bending moment function construction module, a structural deformation reconstruction module, and a graphical display control module; the connection relationship acquisition unit includes a connection relationship acquisition module. The input information, processing content, and output results of each module are shown in Table 3.

[0084] The strain data processing module can perform zero-point correction, filtering, and outlier identification on discrete strain signals; the cross-sectional internal force reconstruction module is used to reconstruct axial force and bending moment; the shear force estimation and correction module is used to obtain the estimated shear force value based on the bending moment difference of adjacent measuring point sections, and can be corrected by combining oblique strain information, strain rose information, external load information, or support reaction force information; the rod end internal force estimation module converts or estimates the rod end internal force based on the internal force of the near-end measuring point section, its geometric positional relationship with the node connection, and known load conditions.

[0085] The data processing and display unit establishes the overall static equilibrium equations based on the structural topology model, external load information, and support constraints:

[0086]

[0087] in, This is the equilibrium matrix established based on the structural topology model, the connection correspondences, and the support constraints. This is an internal force state vector that includes the internal forces at the measuring point section, the internal forces at the rod ends, and the support reactions. This is the external load vector.

[0088] The initial internal force reconstruction result obtained from the discrete strain signal is denoted as... Calculate the equilibrium residuals according to the following formula. :

[0089]

[0090] When the balance residual When the norm does not exceed the preset error limit, the initial internal force reconstruction result is taken as the internal force result after consistency verification; when the equilibrium residual When the norm exceeds the preset error limit, the initial internal force reconstruction result is constrained and corrected under the condition that the overall static equilibrium equation is satisfied.

[0091] The constraint correction can be obtained by solving the following equation:

[0092]

[0093] satisfy:

[0094]

[0095] in, A weight matrix is ​​set according to the measurement accuracy of each measuring point section; a larger weight is set for measuring point sections with higher measurement accuracy, and a smaller weight is set for measuring point sections with larger measurement fluctuations, so as to reduce the difference in internal force results before and after constraint correction under the condition of satisfying the overall static equilibrium relationship.

[0096] When the target structural system is a statically indeterminate structure, the overall static equilibrium relationship is established based on the structural topology model, external load information and support constraints. The deformation coordination relationship is established based on the component parameters, node displacement continuity conditions and node rotation coordination conditions. The internal forces of the measuring point sections obtained from the discrete strain signals are used as observation constraints and are solved together with the overall static equilibrium relationship and deformation coordination relationship to obtain redundant constraint forces or redundant internal forces.

[0097] The bending moment function construction module is used to establish a continuous bending moment function based on the reconstructed bending moment values ​​of each measuring point section after consistency verification and the load type, using interpolation, fitting, or piecewise construction methods. The structural deformation reconstruction module is used to solve the deformation state of the target structural system based on the continuous bending moment function, component parameters, node connection forms, connection degrees of freedom, and support constraints, using the beam deflection curve equation or multi-member compatibility equation.

[0098] The graphical display control module is used to graphically display in real time the structural assembly form, measuring point locations, strain curves at measuring points, axial force distribution, shear force distribution, bending moment distribution, deformation curves, and numerical results of relevant characteristic locations of the target structural system. During the real-time graphical display, the changes in the mechanical state of the target structural system under different node connection forms, connection degrees of freedom, and support constraints can also be presented simultaneously for teaching demonstrations and comparative analysis.

[0099] In another embodiment, the present invention also proposes a discrete strain-driven mechanical state reconstruction method, comprising:

[0100] To meet teaching needs, multiple structural components are assembled into a target structural system using corresponding node connectors. Each structural component has a component identification label, and each node connector has a node identification label. The data processing and display unit reads the component identification labels and node identification labels to obtain component type, component length, cross-sectional parameters, material parameters, measuring point location information, node connection type, connection degrees of freedom, and support constraints. Based on the assembly relationship between the structural components and node connectors, the structural system type of the target structural system is determined.

[0101] During the loading process of the target structural system, the data acquisition unit collects discrete strain signals from multiple strain sensors located at predetermined positions on the structural members. Each strain sensor's location corresponds to a measurement point section of the structural member, and the discrete strain signal can be expressed as... ,in, Indicates the first The position coordinates of the measuring point section along the length of the structural member. For measuring point sections that need to reconstruct both axial force and bending moment simultaneously, strain sensors are preferably set on both sides of the neutral axis of the measuring point section, for example, on the upper and lower surfaces of the structural member, so as to reconstruct the axial force and bending moment of the measuring point section according to the axial average strain and curvature of the section respectively.

[0102] The data processing and display unit converts the discrete strain signals at each measuring point cross-section into normal stresses at the corresponding locations based on Hooke's law for linear elastic materials. Hooke's law can be expressed as:

[0103]

[0104] in, It is normal stress. Let ε be the elastic modulus of the structural member, and ε be the strain.

[0105] For a structural member with strain sensors installed on both sides of the neutral axis of the same measuring point section, the data processing and display unit calculates the axial average strain ε0 and the section curvature κ of the measuring point section based on the discrete strain signals output by the strain sensors on both sides of the neutral axis. The axial average strain ε0 is used to characterize the overall tensile and compressive deformation of the measuring point section, and the section curvature κ is used to characterize the bending deformation of the measuring point section.

[0106] When the distances from the strain sensors located on both sides of the neutral axis of the measuring point section to the neutral axis are known, the section curvature κ can be calculated based on the difference in strain values ​​on both sides of the neutral axis. The average axial strain ε0 of the section can then be calculated based on the average strain values ​​on both sides of the neutral axis or the average strain corrected for the geometric relationship of the measuring point section. Subsequently, the data processing and display unit retrieves the cross-sectional area of ​​the measuring point section based on the component identification. Moment of inertia of cross section And the elastic modulus of the structural member where the measuring point section is located. The axial force at the measuring point section is reconstructed according to the following formula. and bending moment :

[0107]

[0108]

[0109] Where ε0 is the average axial strain of the cross section, and κ is the curvature of the cross section.

[0110] Under the assumption of plane sections, the data processing and display unit can also calculate the internal force values ​​at each measuring point section by combining the cross-sectional geometric parameters of the structural members. (Axial force at the measuring point section...) Bending moment and shear force They can be represented as:

[0111]

[0112]

[0113]

[0114] in, This represents the cross-sectional area of ​​the structural member. This represents the distance from the corresponding position within the measuring point section to the neutral axis. Let be the normal stress at the corresponding position within the cross section of the i-th measuring point.

[0115] Axial force at each measuring point section Bending moment and shear force The shear force can be obtained from discrete strain signals, component parameters, and the internal force variation relationship of adjacent measuring point sections. For shear force, the data processing and display unit can perform differential analysis on the reconstructed bending moment values ​​of adjacent measuring point sections to obtain the estimated shear force value. When it is necessary to improve the accuracy of shear force identification, the estimated shear force value can be further corrected based on at least one of the following: strain information collected from oblique strain measuring points, strain information collected from strain rosettes, external load information provided by the loading measurement device, and support reaction force information provided by the support measurement device.

[0116] For near-end measuring points located near the ends of structural members, the data processing and display unit can calculate or estimate the end forces of the structural members based on the axial force, bending moment, and shear force of the near-end measuring point section, combined with the geometrical positional relationship between the near-end measuring point section and the corresponding node connector, as well as the known load conditions between the near-end measuring point section and the corresponding node connector. By placing the strain sensor near the end of the structural member and maintaining a predetermined distance from the node connector, the influence of the local connection area of ​​the node on the discrete strain signal can be reduced, and the end forces at the corresponding nodes can be obtained using the reconstructed results of the end forces at the near-end measuring point section.

[0117] After obtaining the axial force, bending moment, and shear force at each measuring point section, the data processing and display unit establishes the overall static equilibrium relationship based on the structural system type, node connection form, and support constraint conditions of the target structural system. The overall static equilibrium relationship can be expressed as:

[0118]

[0119] The data processing and display unit substitutes the axial force, bending moment, and shear force at each measuring point section into the overall static equilibrium relationship to verify the consistency of the reconstructed axial force, bending moment, and shear force. When there is a deviation between the reconstructed internal forces and the overall static equilibrium relationship, the data processing and display unit can correct the interpolation results of internal forces at adjacent measuring point sections, the estimation results of internal forces at the rod ends, or the calculation results of redundant constraint forces based on support reaction force information, external load information, or preset error criteria.

[0120] When the target structural system is a statically indeterminate structure, the data processing and display unit can also solve for redundant constraint forces or redundant internal forces by combining the support constraint conditions of the target structural system. The statically indeterminate structure includes continuous beams, rigid frames, and other multi-constraint planar structures assembled from multiple structural components.

[0121] After the consistency verification is completed, the data processing and display unit establishes a continuous bending moment function based on the reconstructed bending moment values ​​of each measuring point section after the consistency verification, using interpolation, fitting, or piecewise construction methods. Continuous bending moment function It is used to characterize the continuous distribution of bending moment along the length of structural members and serves as the basis for reconstructing the deformation state of the target structural system.

[0122] When the target structural system is a beam structure, the data processing and display unit will continuously display the bending moment function. Substituting into the differential equation of the beam deflection curve:

[0123]

[0124] in, For deflection function, Let be the flexural stiffness of the cross section of the corresponding structural member whose deformation is to be solved.

[0125] Integrating the differential equation of the beam deflection curve once yields:

[0126]

[0127] By integrating the differential equation of the beam deflection curve twice, we can obtain:

[0128]

[0129] in, and The integral constant is defined by the data processing and display unit, which solves for the integral constant based on the boundary conditions determined by the support constraints. and For example, boundary conditions at supports may include deflection. The boundary conditions at the fixed end can include zero rotation angle. When the beam structure is a continuous beam, the integral constant is also solved by combining the continuous conditions of span displacement and span rotation angle to obtain the continuous deflection curve of the beam structure.

[0130] Establishing a continuous bending moment function In this case, the data processing and display unit can select the method for establishing the continuous bending moment function based on the load type and the variation characteristics of the bending moment reconstruction values ​​at adjacent measuring point sections. When the load type exhibits concentrated load characteristics, piecewise linear interpolation can be used to establish the continuous bending moment function; when the load type exhibits uniformly distributed load characteristics, quadratic polynomial fitting can be used to establish the continuous bending moment function. By selecting the method for establishing the continuous bending moment function according to the load type, the established continuous bending moment function can correspond to the bending moment variation characteristics under the corresponding load.

[0131] When the target structural system is a rigid frame or other multi-member structure, the data processing and display unit establishes the continuous bending moment function of each structural member in the local coordinate system. Combining the nodal displacement continuity condition, nodal rotation compatibility condition, support constraint condition, and the transformation relationship between the local coordinate system of each structural member and the global coordinate system of the target structural system, the unit establishes the overall deformation compatibility equation or equivalent structural matrix equation of the target structural system. Based on the overall deformation compatibility equation or equivalent structural matrix equation, the data processing and display unit solves for the overall deformation state of the target structural system.

[0132] Therefore, the data processing and display unit can not only reconstruct the continuous deflection curve of a single-span beam or a continuous beam, but also graphically display the beam end rotation, column top lateral displacement, column foot constraint effect and overall deformation mode of multi-member structures such as portal frames.

[0133] The data processing and display unit will graphically display the reconstructed axial force distribution, shear force distribution, bending moment distribution, and deformation state in real time. The displayed content may include a structural schematic diagram of the target structural system, the location of measuring points, the strain change curves of the measuring points, the axial force distribution curve, the shear force distribution curve, the bending moment distribution curve, the deformation curve, and the numerical information of the characteristic locations, so as to intuitively present the changes in the mechanical state of the target structural system during loading and realize the corresponding display between load, discrete strain signal, internal force distribution, and deformation state.

[0134] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0135] Example 1: Basic system structure and general reconfiguration process.

[0136] like Figure 1 As shown, the teaching aid includes multiple standardized structural components 100, multiple node connectors 200, a data acquisition box 300, and a tablet computer 400. The data acquisition box 300 constitutes a data acquisition unit, and the tablet computer 400 constitutes a data processing and display unit.

[0137] Each structural component 100 can adopt a uniform cross-sectional shape but be configured with different length specifications. A strain sensor 110 is encapsulated at a predetermined measuring point cross-section. The measuring point cross-section may include a mid-span cross-section, a quarter-span cross-section, and a near-end measuring point cross-section, such as... Figure 3 As shown. Each structural member 100 is equipped with a member identification mark 130; each node connector 200 is equipped with a node identification mark. According to the end connection form, the structural member 100 includes hinged members and fixed members, which respectively cooperate with hinged nodes and fixed nodes, and the hinged support nodes and fixed support nodes respectively form corresponding support conditions.

[0138] The data acquisition box 300 acquires the discrete strain signal output by the strain sensor 110 and can simultaneously acquire external load information or support reaction force information; the tablet computer 400 establishes a structural topology model based on the component identification 130, node identification and connection correspondence, and completes the section internal force reconstruction, rod end internal force estimation, overall equilibrium verification, continuous bending moment function construction and deformation state reconstruction according to the aforementioned method, and displays the structural schematic diagram, measuring point response, axial force distribution, shear force distribution, bending moment distribution and deformation state in real time.

[0139] Example 2: Simply supported beam experiment.

[0140] like Figure 5 As shown in (a), a simply supported beam is formed by connecting hinged support nodes at both ends. Strain sensors are installed at its mid-span section, quarter-span section, and near-support end measuring point section. During loading, a vertical load can be applied at mid-span. The data processing and display unit reconstructs the internal forces based on the discrete strain signals from each measuring point section. The reconstructed mid-span bending moment value can be compared with the theoretical value. Compare them.

[0141] A continuous bending moment function is established based on the boundary condition that the bending moment at both supports is zero and the reconstructed bending moment values ​​at each measuring point section. Then, by combining the support constraint condition that the deflection at both ends is zero, the continuous deflection curve can be obtained. It can display the response, bending moment distribution, and deformation state of the measuring points in real time. The internal forces at the near-end measuring point sections can also be converted or estimated by combining their geometric positional relationship with the support nodes and known load conditions.

[0142] Example 3: Continuous beam experiment.

[0143] like Figure 5 As shown in (b), a two-span continuous beam is formed by assembling two beam segments and three support nodes. Strain sensors are installed at the mid-span, quarter-span, and near-end measuring point sections of each beam segment, allowing vertical loads to be applied to one span. The data processing and display unit reconstructs the internal forces at each measuring point section based on the discrete strain signals, and solves the internal force state of the continuous beam by combining the structural topology model, support constraints, and observation constraints, thus displaying the positive bending moment within the span and the negative bending moment near the intermediate support.

[0144] A continuous bending moment function is established based on the reconstructed bending moment value after consistency verification. The deformation state of the continuous beam is obtained by combining the support constraint conditions, the continuous displacement condition of the span, and the continuous rotation condition of the span, so as to realize the real-time display of the internal force distribution, support response and deformation state of the continuous beam.

[0145] Example 4: Rigid frame experiment.

[0146] like Figure 5 As shown in (c), two column members and one beam member are connected by a fixed joint to form a portal frame. The bottom of the two column members is connected to a fixed support joint. Strain sensors are installed at the mid-span, quarter-span, and near-end measuring points of the beam members, as well as at the column base, mid-height, and near-end measuring points of the column members, so that horizontal loads can be applied at positions such as the top of the column.

[0147] The data processing and display unit reconstructs internal forces such as beam end bending moment, column base bending moment, and column axial force based on the discrete strain signals of each measuring point section of the beam and column. It then performs consistency verification based on the structural topology model, node connection type, and column base support constraints. Subsequently, it establishes continuous bending moment functions for each structural member in the local coordinate system. Combining the continuous displacement conditions of beam-column nodes, node rotation compatibility conditions, column base support constraints, and the transformation relationship between the local and global coordinate systems, it establishes the overall deformation compatibility equation or equivalent structural matrix equation, solves for the overall deformation state of the portal frame, and displays it in real time.

[0148] Example 5: To further illustrate the teaching demonstration effect of the discrete strain-driven mechanical state reconstruction teaching aid described in this invention, a comparison is made between the traditional patch-type strain teaching experiment and the teaching aid described in this invention. The comparison items include the experimental preparation process, the method of switching the target structure system, the method of parameter calling, the data results, the result processing method, and the teaching demonstration effect.

[0149] In Example 5, to further illustrate the teaching demonstration method of the teaching aid of the present invention and the reconstruction and verification process of different target structural systems, the traditional patch strain experiment is compared with the teaching aid of the present invention, and the results are shown in Table 1; the typical target structural system, loading method, main reconstruction content and verification method are shown in Table 2; the input information, processing content and output results of each functional module of the data processing and display unit are shown in Table 3.

[0150] Table 1 shows a comparison between the traditional patch-type strain test and the teaching aid of this invention:

[0151] Table 1

[0152] Comparison Projects Traditional patch strain test Modular teaching demonstration aids of this invention Experimental preparation Each experiment typically requires strain gauge attachment, wiring, debugging, and calibration, involving a considerable amount of preparation work. The strain sensor is pre-encapsulated in the structural component. During the experiment, the main tasks are component assembly, node connection and data access, which simplifies the preparation process. Structural system switching Different structural systems usually require replacement of test specimens, or rearrangement of test points and connection lines. By replacing standardized structural components and node connectors, structural systems such as simply supported beams, continuous beams, and rigid frames can be assembled on the same teaching platform. Parameter call The length of the component, cross-sectional parameters, material parameters, and the location of the measuring points usually need to be recorded or entered manually. By using component identification and node identification, component parameters, measurement point information, and node constraints can be automatically retrieved. Data Results The main goal is to obtain discrete strain values ​​at several measuring points. Internal force diagrams and deformation curves usually require further processing. Discrete strain data can be further converted into axial force distribution, shear force distribution, bending moment distribution, and deformation curves. Result Processing It usually requires manual calculation after class, or post-processing with the help of other software. It can perform strain calculation, internal force reconstruction, balance verification and deformation reconstruction in real time during the loading process. Teaching demonstration Students find it difficult to simultaneously observe the relationship between load, strain, internal force, and deformation during the loading process. It can simultaneously display structural schematic diagrams, measurement point responses, internal force distribution, and deformation status, facilitating the establishment of the correspondence between load, strain, internal force, and deformation.

[0153] The typical target structure, loading method, main reconstruction content, and possible verification methods are summarized in Table 2:

[0154] Table 2

[0155] Simply supported beam Concentrated load or uniformly distributed load at mid-span. Mid-span bending moment, shear force distribution, bending moment distribution, and deflection curve. The mid-span bending moment can be compared with the theoretical value M=PL / 4 or the corresponding theoretical solution; the bending moment at the support should satisfy the simply supported boundary conditions. Continuous beam Single-span loading or multi-span loading. Positive bending moment within the span, negative bending moment at intermediate supports, changes in support reaction force, and continuous deformation curves. Consistency verification is performed based on support reactions, span continuity conditions, and negative bending moment characteristics of intermediate supports. Portal frame Vertical load at mid-span of beam, load at beam end, or horizontal load at column top. Beam end bending moment, column base bending moment, column axial force, internal forces near nodes, and frame lateral displacement. Consistency verification is performed based on node balance relationships, column base constraints, beam-column connection coordination conditions, and frame lateral displacement trends.

[0156] The input information, processing content, and output results of each functional module can be summarized in Table 3:

[0157] Table 3

[0158] Module Name Input information Processing content Output Component parameter calling module Component identification. The system retrieves the component length, cross-sectional area, moment of inertia, elastic modulus, coordinates of the measuring point, and distance from the measuring point to the neutral axis. Component parameters and measuring point location information. Node constraint recognition module Node identity identifier. Identify node types, connection degrees of freedom, constraint directions, and support boundary conditions. Node connection type and boundary constraint information. Strain data processing module Real-time strain signal. Zero-point correction, filtering, and outlier identification are performed. Effective discrete strain data. Section internal force reconstruction module Strain values, cross-sectional parameters, and measurement point locations of the upper and lower surfaces. Calculate the axial average strain and curvature of the cross section, and reconstruct the axial force and bending moment accordingly. Axial force and bending moment of the cross section. Shear force estimation and correction module Adjacent section bending moment, oblique strain measurement points, strain rosette, external load information or support reaction force information. Shear force can be obtained or corrected through moment difference, shear strain transformation calculation, or static equilibrium relationship. Shear force distribution information. Rod end internal force estimation module Internal forces at the near-end measuring point section, distance from the measuring point to the node, and known load conditions. Convert or correct the internal forces at the near end section to the internal forces at the end of the rod at the node. Axial force at the end of the bar, shear force at the end of the bar, and bending moment at the end of the bar. Overall balance verification module Structural topology model, internal forces at measuring points, internal forces at rod ends, external load information, support reaction information, and support constraint conditions. The overall static equilibrium relationship is established based on the structural topology model, the equilibrium residual is calculated, and the initial internal force reconstruction result is constrained and corrected when the equilibrium residual exceeds the preset error limit. Balanced residuals, consistency verification results, and internal force information after constraint correction. Bending moment function construction module Discrete bending moment points, load types, and boundary conditions. Continuous bending moment functions can be established using interpolation, fitting, or piecewise construction methods. Continuous bending moment function. Structural Deformation Reconstruction Module Continuous bending moment function, boundary conditions, nodal continuity conditions, and support constraints. Solve for the deflection curve of beam structures, the deformation curve of continuous beams, or the overall deformation state of rigid frames. Deformation curve, node rotation angle, and characteristic displacement. Graphical display control module Strain, axial force, shear force, bending moment, and deformation data. Generate structural schematic diagrams, measurement point response curves, internal force diagrams, and deformation diagrams. The results are displayed graphically in real time. Connection relationship acquisition module Information on the ends of each structural component and information on each node connector. Obtain the connection correspondence between the ends of each structural component and each node connector. Connect the corresponding relationships. Structural topology modeling module Connection correspondence, component parameters, measuring point location information, node connection form, connection degree of freedom and support constraint conditions. Establish a structural topology model of the target structural system and determine the structural system type. Structural topology models and structural system types.

[0159] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A teaching aid for reconstructing mechanical states driven by discrete strain, characterized in that, include: Multiple structural components, each of which is equipped with a component identification mark and strain sensors located at multiple measuring point sections, wherein the strain sensors are respectively provided on both sides of the neutral axis of each measuring point section used to reconstruct axial force and bending moment; A connection relationship acquisition unit is used to acquire the connection correspondence between the ends of each of the structural components and each of the node connectors; A data acquisition unit, connected to the strain sensor, is used to acquire the discrete strain signal output by the strain sensor; The data processing and display unit, which is communicatively connected to the data acquisition unit, is used for: Component parameters and measurement point location information are obtained based on the component identification, node connection form, connection degree of freedom and support constraint conditions are obtained based on the node identification, and a structural topology model of the target structural system is established based on the connection correspondence to determine the structural system type of the target structural system; Based on the discrete strain signal and the component parameters, the axial force and bending moment of each measuring point section are reconstructed, and the shear force is obtained based on the reconstructed bending moment value of adjacent measuring point sections. Based on the structural system type, the node connection form, and the support constraint conditions, an overall static equilibrium relationship is established, and the consistency of the reconstructed axial force, bending moment, and shear force is verified. A continuous bending moment function is constructed based on the reconstructed bending moment values ​​of each measuring point section after consistency verification. The deformation state of the target structural system is then reconstructed based on the continuous bending moment function, the component parameters, the node connection type, the connection degrees of freedom, and the support constraints. The system graphically displays in real time the axial force distribution, shear force distribution, bending moment distribution, and deformation state of the target structural system.

2. The discrete strain-driven mechanical state reconstruction teaching aid according to claim 1, characterized in that, All structural components adopt a uniform cross-sectional shape and are configured with different length specifications according to the target structural system; The measuring point section includes at least one of the mid-span section, the quarter-point section, and the near-end measuring point section close to the end of the structural member; The measuring section used to identify shear force is also equipped with an oblique strain sensor or strain rosette.

3. The discrete strain-driven mechanical state reconstruction teaching aid according to claim 1, characterized in that, Each of the structural components includes a main rod body, a sensor packaging area, a wire channel, and an identification tag installation area; The sensor encapsulation area is a shallow groove on the surface of the rod body, an embedded groove inside the rod body, or a thin-walled encapsulation area on the rod body. The strain sensor is encapsulated in the sensor encapsulation area, and the sensitive grid direction of the strain sensor is consistent with the axial direction or predetermined measurement direction of the rod body. The wire channel is set along the length of the main body of the rod or a reserved path inside the main body of the rod, and is used to arrange the wires connecting the strain sensor and the data acquisition unit; A protective layer is provided on the outside of the sensor packaging area. The protective layer is used to protect the strain sensor and maintain the deformation transmission relationship between the strain sensor and the main body of the rod.

4. The discrete strain-driven mechanical state reconstruction teaching aid according to claim 1, characterized in that, The structural member includes a hinged member and a fixed member, and the hinged member and the fixed member each have an end connection structure integrally formed with the end of the corresponding member; The end of the hinge member is provided with an ear plate and a pin hole. The node connector includes a hinge node. The hinge node is provided with a connecting part that cooperates with the ear plate. The pin passes through the pin hole and the connecting part so that the hinge member is rotatably connected to the hinge node. The end of the fixed rod is provided with a rectangular end, and the node connector also includes a fixed node. The fixed node is provided with a rectangular insertion cavity that mates with the rectangular end. After the rectangular end is inserted into the rectangular insertion cavity, the fixed rod is restricted from axially disengaging by a limiting member, and the fixed rod is restricted from rotating relative to the fixed node by a rigid rotation limiting sleeve or rigid covering structure disposed outside the insertion area formed by the rectangular end and the rectangular insertion cavity. The limiting component is a limiting pin or a limiting pin block; The node connector also includes a hinged support node and a fixed support node. The hinged support node is formed by combining the hinged node with the base plate, and the fixed support node is formed by combining the fixed node with the base plate.

5. The discrete strain-driven mechanical state reconstruction teaching aid according to claim 1, characterized in that, The data acquisition unit is also connected to at least one of the loading measuring device and the support measuring device; The loading measurement device is used to provide external load information to the data acquisition unit, and the support measurement device is used to provide support reaction force information to the data acquisition unit.

6. A discrete strain-driven mechanical state reconstruction method, characterized in that, include: Multiple structural components are assembled into a target structural system through multiple node connectors, and the connection correspondence between the ends of each structural component and each node connector is obtained; Read the component identification and the node identification to obtain component parameters, measurement point location information, node connection type, connection degree of freedom and support constraint conditions; Based on the connection correspondence, establish the structural topology model of the target structural system and determine the structural system type of the target structural system; Collect the discrete strain signals output by the strain sensor; Based on the discrete strain signal and the component parameters, the axial force and bending moment of each measuring point section are reconstructed, and the shear force is obtained based on the reconstructed bending moment value of adjacent measuring point sections. Based on the structural topology model, structural system type, node connection form, external load information, and support constraint conditions, an overall static equilibrium relationship is established, and the consistency of the reconstructed axial force, bending moment, and shear force is verified. A continuous bending moment function is constructed based on the bending moment reconstruction values ​​of each measuring point section after consistency verification, and the deformation state of the target structural system is reconstructed based on the continuous bending moment function, the component parameters, the node connection form, the connection degree of freedom, and the support constraint conditions. as well as The system graphically displays in real time the axial force distribution, shear force distribution, bending moment distribution, and deformation state of the target structural system.

7. The discrete strain-driven mechanical state reconstruction method according to claim 6, characterized in that, The axial average strain of the cross-section at the measuring point is calculated based on the discrete strain signals output by the strain sensors located on both sides of the neutral axis of the same measuring point cross-section. and cross-sectional curvature ; The cross-sectional area of ​​the measuring point is retrieved based on the component's identification. Moment of inertia of cross section and the elastic modulus of the structural member where the measuring point section is located The axial force at the measuring point section is calculated according to the following formula. and bending moment : ； 。 8. The discrete strain-driven mechanical state reconstruction method according to claim 6, characterized in that, The bending moment reconstruction values ​​of adjacent measuring point sections are differentially analyzed to obtain the estimated shear force value. The estimated shear force value is then corrected based on at least one of the strain information collected from the oblique strain measuring point, the strain information collected from the strain rosette, the acquired external load information, and the acquired support reaction force information. For the near-end measuring point section close to the end of the structural member, based on the axial force, bending moment and shear force of the near-end measuring point section, combined with the geometric positional relationship between the near-end measuring point section and the corresponding node connector and the known load conditions, the end force of the structural member is converted or estimated. When the result of the consistency verification does not meet the preset error criterion, the interpolation result of the internal force of the adjacent measuring point section or the estimation result of the internal force of the rod end is corrected according to at least one of the external load information and the support reaction force information. When the target structural system is a statically indeterminate structure, an overall static equilibrium relationship is established based on the structural topology model, external load information, and support constraint conditions, and a deformation coordination relationship is established based on the component parameters, node displacement continuity conditions, and node rotation coordination conditions. The internal forces of the measuring point sections obtained based on the discrete strain signals are used as observation constraints and are solved jointly with the overall static equilibrium relationship and the deformation coordination relationship to obtain the redundant constraint forces or redundant internal forces of the target structural system.

9. The discrete strain-driven mechanical state reconstruction method according to claim 6, characterized in that, When establishing the continuous bending moment function, the segmented control position is determined based on the known load type, load application location, node location, component end location, and the variation characteristics of the bending moment reconstruction value of adjacent measuring point sections. When the structural member is subjected to a concentrated force, the position of the concentrated force, the position of the node, and the position of the end of the member are used as the segmented control positions. A segmented bending moment function is established in each segment using a linear function or a low-order polynomial, and a bending moment continuity condition is applied at the position of the concentrated force. When the structural member is subjected to a concentrated moment, a bending moment abrupt change condition is applied at the location where the concentrated moment is applied. When the structural member is subjected to a uniformly distributed load, a quadratic polynomial is used to establish the bending moment function of the corresponding section. The undetermined parameters in the piecewise bending moment function are determined based on the reconstructed bending moment values ​​at each measuring point section, the end boundary conditions, and the nodal equilibrium conditions. When the target structural system is a beam structure, the continuous bending moment function is denoted as... and the continuous bending moment function Substituting into the differential equation of the beam deflection curve: in, For deflection function, This refers to the flexural stiffness of the corresponding structural member's cross-section; The differential equation of the beam deflection curve is integrated twice, and the integration constant is solved based on the boundary conditions determined by the support constraints. When the beam structure is a continuous beam, the integration constant is also solved in combination with the continuous conditions of span displacement and span rotation, so as to obtain the continuous deflection curve of the beam structure.

10. The discrete strain-driven mechanical state reconstruction method according to claim 6, characterized in that, When the target structural system is a rigid frame or other multi-member structure, the continuous bending moment function of each structural member in the local coordinate system is established respectively. Based on the nodal displacement continuity condition, nodal rotation coordination condition, the support constraint condition, and the transformation relationship between the local coordinate system and the global coordinate system, establish the overall deformation coordination equation or equivalent structural matrix equation of the target structural system. The overall deformation state of the target structural system is solved based on the overall deformation compatibility equation or the equivalent structural matrix equation.

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