Self-piercing riveting joint simulation model
Through the simulation model of self-punching riveting joints, the rivet damage is monitored by comparing dynamic deformation energy and static combination energy, combined with temperature monitoring and stress and strain tests, the problem of lack of precise analysis of the self-punching riveting process in the existing technology is solved, and high precision is achieved Optimized design and damage assessment.
Patent Information
- Application Number
- CN202421096959.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-20
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2034-05-20
AI Technical Summary
The prior art lacks simulation models that can accurately analyze the self-punching riveting process, resulting in a lack of safety guarantee for the self-punching riveting process, and it is difficult to achieve high precision in the optimized design of multiple riveting points.
Provide a simulation model of self-impact riveting joints, including simulated rivet structures, first and second connecting plates, stress nodes, failure rings and fixtures, monitoring rivet damage through comparison of dynamic deformation energy and static binding energy, and combining temperature The monitoring point takes into account the influence of thermal energy and conducts stress and strain tests to determine the maximum deformation energy.
It realizes accurate damage monitoring and optimized design of the self-imping riveting process, improves the design accuracy and safety of large-scale self-imping riveting, simplifies the calculation amount, and is suitable for universal applications in engineering.
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Figure CN222281228U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of connection equipment performance analysis, in particular to a self-piercing riveted joint simulation model. Background Art
[0002] Traditionally, automobile body manufacturing materials mainly use steel. With the increasing requirements for automobile lightweighting and energy conservation and emission reduction, and with the development of lightweight materials such as ultra-high-strength steel, magnesium (aluminum) alloys, and composite materials, the mixed use of multiple materials has become an important lightweight technical means in automobile manufacturing according to the load-bearing mode, stress conditions, and functional requirements of different components and systems. Since it involves the connection of heterogeneous materials and metal-non-metallic materials, self-piercing riveting is often used as the connection process. Self-piercing riveting is a cold forming technology. Under mechanical pressure, the punch and the lower die work together to cause permanent plastic deformation of the connected parts and rivets and form an internal locking structure to form a connection.
[0003] Self-piercing riveting has the advantages of high connection strength and easy implementation. It is especially suitable for mixed connections of various heterogeneous materials and metal / non-metallic materials. However, since the riveting process involves complex spatial plastic deformation, local damage, hardening and interface friction, it is necessary to consider the strain rate effect, thermal softening effect and substrate pre-strain. In actual self-piercing riveting applications, there are often hundreds of rivet points. The optimization design of the strength, position, number, etc. of these rivet points depends on a high-precision self-piercing riveting model, and the model must be simple and low in computational complexity. The existing technology lacks a simulation model that can accurately analyze the riveting process, resulting in a lack of safety assurance for the self-piercing riveting process. Utility Model Content
[0004] The utility model provides a self-piercing riveted joint simulation model, which can characterize the area where the rivet is damaged during use through a failure ring. The simulation model can test the dynamic deformation energy and static binding energy during the riveting process, and can be applied to the optimization design and damage failure evaluation of large-scale self-piercing riveting.
[0005] The utility model provides a self-piercing riveting joint simulation model, comprising: a simulation rivet structure, a first connecting plate and a second connecting plate;
[0006] The first connecting plate and the second connecting plate are respectively provided with four stress nodes, and the stress nodes are used to bear the spatial stress from the outside and generate dynamic deformation energy;
[0007] The simulated rivet structure is connected to the first connecting plate via a first failure ring, and the simulated rivet structure is connected to the second connecting plate via a second failure ring, and the first failure ring and the second failure ring are used to characterize the damage area of the simulated rivet structure;
[0008] Static binding energy is generated during the connection process between the simulated rivet structure and the first connecting plate and the second connecting plate. The magnitude relationship between the static binding energy and the dynamic deformation energy reflects the damage of the simulated rivet structure.
[0009] According to the self-piercing riveted joint simulation model provided by the utility model, the simulated rivet structure is a hexahedral structure, and two opposite surfaces of the simulated rivet structure are respectively connected to the first connecting plate and the second connecting plate.
[0010] According to the self-piercing riveted joint simulation model provided by the utility model, each stress node is subjected to spatial stress in three directions, and the spatial stresses in the three directions are perpendicular to each other.
[0011] According to the self-piercing riveted joint simulation model provided by the utility model, it also includes a temperature monitoring point, which monitors the temperature changes during the connection process of the simulated rivet structure and the first connecting plate and the second connecting plate. The temperature changes represent the heat energy generated during the riveting process, and the static binding energy is the difference between the total input energy and the heat energy.
[0012] The self-piercing riveted joint simulation model provided by the utility model also includes a first clamp and a second clamp, the first clamp clamps the first failure ring, and the second clamp clamps the second failure ring;
[0013] The first fixture performs a stress-strain test on the first failure ring to determine the maximum deformation energy of the first failure ring;
[0014] The second fixture performs a stress-strain test on the second failure ring to determine the maximum deformation energy of the second failure ring.
[0015] According to the self-piercing riveted joint simulation model provided by the utility model, the stress-strain test includes a shear test, a tensile test and a peel test.
[0016] In the self-piercing riveted joint simulation model provided by the utility model, the external spatial stress can be borne by the stress nodes on the first connecting plate and the second connecting plate, and the spatial stress can be transmitted to the failure ring area in the form of dynamic deformation energy. The static binding energy generated in the riveting process can also be mapped to the failure ring area. In this way, the failure ring area can be further analyzed. Specifically, the dynamic deformation energy and the static binding energy of the failure ring area can be compared. If the dynamic deformation energy is greater than the static binding energy, it means that the simulated rivet may be damaged. In this way, the damage condition of the rivet can be accurately monitored, which can be subsequently applied to the optimization design and damage failure assessment of large-scale self-piercing riveting. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0018] Figure 1 This is one of the structural schematic diagrams of the self-piercing riveted joint simulation model provided by the embodiment of the utility model;
[0019] Figure 2 This is the second structural schematic diagram of the self-piercing riveted joint simulation model provided by the embodiment of the utility model;
[0020] Figure 3 It is a structural schematic diagram of a self-piercing riveted joint provided by an embodiment of the utility model;
[0021] Figure 4 This is one of the flow diagrams of the self-piercing riveted joint modeling method provided by the embodiment of the utility model;
[0022] Figure 5 This is the second flow chart of the self-piercing riveted joint modeling method provided by the embodiment of the utility model;
[0023] Figure 6 It is a schematic diagram of a stress-strain test provided in an embodiment of the utility model. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0025] Figure 1 It is one of the structural schematic diagrams of the self-piercing riveted joint simulation model provided by the embodiment of the utility model.
[0026] Figure 2 This is the second structural schematic diagram of the self-piercing riveted joint simulation model provided by the embodiment of the utility model.
[0027] like Figure 1 and Figure 2 As shown, this embodiment provides a self-piercing riveted joint simulation model, including: a simulated rivet structure, a first connecting plate and a second connecting plate;
[0028] The first connecting plate and the second connecting plate are respectively provided with four stress nodes, and the stress nodes are used to bear the spatial stress from the outside and generate dynamic deformation energy;
[0029] The simulated rivet structure is connected to the first connecting plate via a first failure ring, and the simulated rivet structure is connected to the second connecting plate via a second failure ring, and the first failure ring and the second failure ring are used to characterize the damage area of the simulated rivet structure;
[0030] Static binding energy is generated during the connection process between the simulated rivet structure and the first connecting plate and the second connecting plate. The magnitude relationship between the static binding energy and the dynamic deformation energy reflects the damage of the simulated rivet structure.
[0031] In practical applications, such as Figure 1 As shown, U1, U2, U3 and U4 may be stress nodes of the first connecting plate, and D1, D2, D3 and D4 may be stress nodes of the second connecting plate.
[0032] Figure 3 It is a structural schematic diagram of a self-piercing riveted joint provided by an embodiment of the utility model.
[0033] like Figure 3 As shown in the figure, in actual application, self-piercing riveting mainly bears complex spatial loads, and the load is transmitted to the riveted area through the connecting plate. Its damage failure mode is mainly the self-locking structure of the connecting piece and the rivet is destroyed and peeled off, which is neither the fracture of the connecting plate nor the fracture of the rivet itself. The location of the fracture is mainly in the area of the rivet root, that is, Figure 3 The locking structure in.
[0034] In this embodiment, by constructing Figure 1 The simulation model shown in the figure defines a “failure ring” to represent the actual failure area of the rivet root. When the riveted structure is subjected to complex spatial loads, each node on the connecting plate unit will be subjected to spatial stress in three directions, namely Figure 1 The fx, fy and fz in the simulation generate corresponding strains and are transferred to the “failure ring” area in the form of dynamic deformation energy. The plastic deformation energy, residual strain energy, interface friction energy and part of the thermal energy generated in the riveting process are stored in the simulated rivet structure in the form of static binding energy and mapped to the “failure ring” area. By comparing the dynamic deformation energy and static binding energy, it is determined whether damage failure occurs.
[0035] In the self-piercing riveted joint simulation model provided in this embodiment, the external spatial stress can be borne by the stress nodes on the first connecting plate and the second connecting plate, and the spatial stress can be transferred to the failure ring area in the form of dynamic deformation energy. The static binding energy generated during the riveting process can also be mapped to the failure ring area. In this way, the failure ring area can be further analyzed. Specifically, the dynamic deformation energy and the static binding energy of the failure ring area can be compared. If the dynamic deformation energy is greater than the static binding energy, it means that the simulated rivet may be damaged. In this way, the damage of the rivet can be accurately monitored, which can be subsequently applied to the optimization design and damage failure assessment of large-scale self-piercing riveting.
[0036] In an exemplary embodiment, the simulated rivet structure is a hexahedral structure, and two opposite surfaces of the simulated rivet structure are respectively connected to the first connecting plate and the second connecting plate.
[0037] In practical applications, such as Figure 1 As shown, the structure of the simulated rivet can be abstracted as a hexahedral structure, which can facilitate the subsequent force analysis of the simulated rivet.
[0038] In an exemplary embodiment, each stress node is subjected to spatial stress in three directions, and the spatial stress in the three directions are perpendicular to each other.
[0039] In an exemplary embodiment, Figure 2 As shown, the self-piercing riveted joint simulation model also includes a temperature monitoring point, which monitors the temperature change during the connection process of the simulated rivet structure and the first connecting plate and the second connecting plate. The temperature change represents the heat energy generated during the riveting process, and the static binding energy is the difference between the total input energy and the heat energy.
[0040] In an exemplary embodiment, the self-piercing riveted joint simulation model further includes a first clamp and a second clamp, the first clamp clamping the first failure ring, and the second clamp clamping the second failure ring;
[0041] The first fixture performs a stress-strain test on the first failure ring to determine the maximum deformation energy of the first failure ring;
[0042] The second fixture performs a stress-strain test on the second failure ring to determine the maximum deformation energy of the second failure ring.
[0043] In an exemplary embodiment, the stress-strain test includes a shear test, a tensile test, and a peel test.
[0044] The following is an introduction to the modeling method of the self-piercing riveted joint simulation model provided by the present invention. The self-piercing riveted joint modeling method described below and the self-piercing riveted joint simulation model described above can be referenced to each other.
[0045] Figure 4It is one of the flow diagrams of the self-piercing riveted joint modeling method provided in the embodiment of the utility model.
[0046] Figure 5 This is the second flow chart of the self-piercing riveted joint modeling method provided in the embodiment of the utility model.
[0047] like Figure 4 and Figure 5 As shown, the self-piercing riveted joint modeling method provided in this embodiment includes:
[0048] Step 401, establishing a three-dimensional mechanical model based on a rivet structure and a connector structure, wherein the connector is a structure in contact with the rivet during the riveting process, and the connector structure includes a first connector and a second connector;
[0049] Step 402, determining the equivalent bonding energy between the rivet structure and the connector structure based on the three-dimensional mechanical model;
[0050] Step 403, building a damage law model, and determining the maximum deformation energy of the rivet structure based on the damage law model;
[0051] Step 404: determining the damage condition of the rivet structure based on the relationship between the equivalent binding energy and the maximum deformation energy.
[0052] The following is an example of a specific embodiment to illustrate the self-piercing riveted joint modeling method provided by the solution of the present application, which mainly includes determining the self-piercing riveting damage failure criterion and constructing a three-dimensional mechanical model.
[0053] The main criteria for determining the failure of self-piercing riveting damage include:
[0054] First, the riveting process pressure test can be carried out on the steel-aluminum connecting plate. The test can be carried out using a self-piercing riveting tester, and the total input energy of the riveting process can be obtained according to the displacement-load curve obtained in each test. During the riveting process, a thermal imaging camera is used to monitor the temperature changes of the monitoring points during the riveting process, and the heat energy generated by the riveting process is obtained accordingly. The difference between the total input energy and the heat energy is defined as the actual riveting bonding energy, where the riveting bonding energy can include the plastic deformation energy of the rivet and the connecting part, the residual strain energy caused by pressure, and the interface friction energy.
[0055] After that, a special test fixture can be made to carry out the "failure ring" destruction tensile test, that is, the stress-strain test, and ensure that the connecting plates outside the "failure ring" area are not involved in the destruction process. The test is planned to be carried out using an MTS tensile testing machine. The total energy of the destruction process is obtained based on the displacement-load curve obtained in each test, and compared with the riveting static bonding energy obtained in the previous step for verification. The test process requires multiple sets of samples.
[0056] Figure 6It is a schematic diagram of a stress-strain test provided in an embodiment of the utility model.
[0057] In practical applications, such as Figure 6 As shown, stress-strain tests may include shear tests, tensile tests, and peel tests.
[0058] The self-piercing riveted joint modeling method and the applied simulation model provided in this embodiment have at least the following beneficial effects:
[0059] The simple model based on experimental data for theoretical modeling has very low calculation amount and strong universality in engineering. It can be applied to the optimization design and damage failure assessment of large-scale self-piercing riveting.
[0060] The "failure ring" model is constructed based on the energy principle, which can fully consider the factors such as residual stress, work hardening and interface friction in the riveting process, and has high prediction accuracy under complex spatial deformation conditions;
[0061] The model and modeling method are simple and easy to operate, and can be easily implemented in engineering and on-site, and have strong engineering promotion value.
[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.
Claims
1. Self-piercing riveted joint simulation model, characterized in that: include: A simulated rivet structure, a first connecting plate and a second connecting plate; The simulated rivet structure is a hexahedral structure, and two opposite surfaces of the simulated rivet structure are respectively connected to the first connecting plate and the second connecting plate; The first connecting plate and the second connecting plate are respectively provided with four stress nodes, and the stress nodes are used to withstand the spatial stress from the outside and generate dynamic deformation energy; The simulated rivet structure is connected to the first connecting plate via a first failure ring, and the simulated rivet structure is connected to the second connecting plate via a second failure ring, wherein the first failure ring and the second failure ring are used to characterize a damage area of the simulated rivet structure; Static binding energy is generated during the connection process between the simulated rivet structure and the first connecting plate and the second connecting plate. The magnitude relationship between the static binding energy and the dynamic deformation energy reflects the damage condition of the simulated rivet structure.
2. The self-piercing riveted joint simulation model according to claim 1, characterized in that: Each of the stress nodes is subjected to spatial stress in three directions, and the spatial stresses in the three directions are perpendicular to each other.
3. The self-piercing riveted joint simulation model according to claim 1, characterized in that: It also includes a temperature monitoring point, which monitors the temperature change during the connection process of the simulated rivet structure and the first connecting plate and the second connecting plate. The temperature change represents the heat energy generated during the riveting process, and the static binding energy is the difference between the total input energy and the heat energy.
4. The self-piercing riveted joint simulation model according to claim 1, characterized in that: Also includes a first clamp and a second clamp, the first clamp clamps the first failure ring, and the second clamp clamps the second failure ring; The first fixture performs a stress-strain test on the first failure ring to determine the maximum deformation energy of the first failure ring; The second fixture performs a stress-strain test on the second failure ring to determine the maximum deformation energy of the second failure ring.
5. The self-piercing riveted joint simulation model according to claim 4, characterized in that: The stress-strain test includes a shear test, a tensile test and a peel test.