CN-122020977-A - Multi-machine heat production efficiency dynamic calculation method for variable-angle layered thermoplastic composite material induction welding

CN122020977ACN 122020977 ACN122020977 ACN 122020977ACN-122020977-A

Abstract

The invention provides a dynamic calculation method for multi-machine heat production efficiency of variable-angle layering thermoplastic composite material induction welding, belonging to the technical field of thermoplastic composite material structure forming; the method comprises the steps of establishing heat-generating models of layered thermoplastic composite materials with different angles based on material microstructure, respectively establishing quantitative relations of three heat-generating mechanisms of dielectric loss, contact resistance heating and fiber heating and the angles of the layers based on the heat-generating models, performing induction welding tests on the same thermoplastic composite material laminated plates with different angles of the layers and measuring total heat production quantity of the same thermoplastic composite material laminated plates, simultaneously calculating to obtain general proportionality coefficients irrelevant to the angles of the layers, and calculating or predicting the duty ratio and the heat production quantity of each heat-generating mechanism under different angles of the layers by utilizing the general proportionality coefficients and the quantitative relations. The invention overcomes the limitation that the existing method is only suitable for specific layering, and provides an accurate and efficient theoretical tool for the collaborative optimization of the structural design of the composite material and the welding process.

Inventors

WANG SHIYU
ZHOU YANAN
LI MENGJUAN
WEN LIHUA
FU RAO

Assignees

西北工业大学

Dates

Publication Date: 20260512
Application Date: 20251230

Claims (10)

1. The dynamic calculation method for the multi-machine heat production efficiency of the variable-angle layered thermoplastic composite material induction welding is characterized by comprising the following steps of: Step 1, building heat-generating models of thermoplastic composite materials paved at different angles based on a material microstructure, wherein the heat-generating models comprise at least one key parameter which is constructed as a function of a paving angle theta, so that the models can dynamically respond to the change of the paving angle; step 2, based on the heat generation model, respectively establishing quantitative relations of three heat generation mechanisms of dielectric loss, contact resistance heating and fiber heating and the angle of the layering; Step 3, performing an induction welding test on at least two thermoplastic composite material laminated plates with different layering angles, and measuring the total heat generation quantity of the thermoplastic composite material laminated plates; And 4, based on the quantitative relation established in the step 2 and the total heat generation amount measured in the step 3, calculating simultaneously to obtain a general scaling factor irrelevant to the angle of the pavement, and calculating or predicting the duty ratio and the heat generation amount of each heat generation mechanism under different angles of the pavement by utilizing the general scaling factor and the quantitative relation.
2. The method for dynamically calculating the heat generation efficiency of the variable angle mat thermoplastic composite material induction welding machine according to claim 1, wherein in the step 1, the key parameters include a dielectric loss resistance R jd at a mat node, and the dielectric loss resistance R jd is constructed as a function of the mat angle θ, and the expression is: wherein h represents the thickness of the resin, Indicating the angular frequency of the alternating current, The dielectric constant of the vacuum is indicated, Represents the dielectric constant of the resin matrix, Represents the retardation angle of the resin matrix, a j represents the contact area between the resin matrices, The angle between the plies is expressed, a is the thickness of the individual composite fibers, and d f is the diameter of the individual fiber bundles of the individual composite fibers.
3. The method for dynamically calculating the heat generating efficiency of the variable angle thermoplastic composite material induction welding process according to claim 2, wherein in said step 1, the key parameters further include the contact resistance at the junction Or contact resistivity The contact resistance Or contact resistivity Is constructed to be at an angle to the layup Is expressed as: 。
4. The method for dynamically calculating the heat generation efficiency of the variable angle laminated thermoplastic composite material induction welding machine according to claim 3, wherein in the step 2, the quantitative relationship between the dielectric loss and the fiber heating is a quantitative ratio relationship M, and the quantitative relationship between the contact resistance heating and the fiber heating is a quantitative ratio relationship N, wherein M and N are both the angles of the laminated thermoplastic composite material induction welding machine The functional expressions of (2) are: 。
5. the method for dynamically calculating the heat generation efficiency of the variable angle laminated thermoplastic composite material induction welding machine according to claim 4, wherein in the step 3, the total heat generation amount Q is determined by the following formula: Wherein, the Indicating the total heat generation of induction welding of the composite laid at an angle, Represents the specific heat capacity of the composite material, Indicating the mass of a composite lay-up laid at an angle, And The temperature start and end values of the composite material laid at a certain angle in the induction welding test are respectively shown.
6. The method for dynamically calculating the heat generation efficiency of the variable angle-spread thermoplastic composite material induction welding machine according to claim 5, wherein in the step 4, the common scale factor comprises a first scale factor and a second scale factor, and wherein: the first ratio coefficient is defined as the ratio of the total resistance in the thickness direction of the laminated plates with two different layering angles, namely C jt =R jt1 /R jt2 , wherein R jt1 、R jt2 respectively represents the total resistance in the thickness direction of the layering of the same material with the angle of 1 and the layering of the same material with the angle of 2; The second proportionality coefficient is defined as the ratio of dielectric loss to fiber heating of two different ply angle laminates, namely C M =M 1 /M 2 , wherein M 1 and M 2 respectively represent the ratio of dielectric loss to fiber heating at the ply node of angle 1 and angle 2 of the same material.
7. The method for dynamically calculating the heat generation efficiency of the variable angle layered thermoplastic composite material induction welding machine according to claim 6, wherein in the step 4, the dielectric loss ratio m and the contact resistance heating ratio n are obtained by solving the following simultaneous equations, and the first proportionality coefficient C jt and the second proportionality coefficient C M are further obtained: Wherein, the And The heat of fiber heating for angle 1 ply and angle 2 ply of the same material respectively, And The total heat production of the angle 1 layer and the angle 2 layer of the same material are respectively shown, The contact resistivity of the angle 1 ply of the same material is shown, The contact resistivity of the angle 2 ply of the same material is shown.
8. The method for dynamically calculating the heat generation efficiency of the variable angle ply thermoplastic composite material induction welding multi-machine according to claim 7, wherein in the step 4, after the universal scaling factor is obtained, the predicted value of the total heat generation amount of any new ply angle 2 is calculated according to the model parameter relation with the known ply angle 1 : Introducing compensation coefficient to represent the ratio relation of total induction heating and contact resistance heating of the composite material laminated plate, wherein the compensation coefficient is The calculation formula of (2) is as follows: Wherein, the Indicating the total heat generation of induction welding of the composite laid at an angle, Representing the heat generated by the induction welding contact resistance of a composite laid at an angle.
9. The method for dynamically calculating the induction welding multi-machine heat production efficiency of the variable angle layered thermoplastic composite material according to claim 1, wherein the thermoplastic composite material is a carbon fiber reinforced polyether ether ketone CF/PEEK composite material.
10. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the variable angle ply thermoplastic composite induction welding multi-machine thermal efficiency dynamic calculation method of any one of claims 1-9 when the program is executed by the processor.

Description

Multi-machine heat production efficiency dynamic calculation method for variable-angle layered thermoplastic composite material induction welding Technical Field The invention belongs to the technical field of thermoplastic composite material structure forming, and particularly relates to a variable-angle layered thermoplastic composite material induction welding multi-machine heat production efficiency dynamic calculation method. Background Thermoplastic composite materials are increasingly used in the field of manufacturing high-end equipment such as aerospace, automobiles and the like with high specific strength, excellent fatigue resistance and repeatability in processing. Thermoplastic composite materials, represented by carbon fiber reinforced polyetheretherketone (CF/PEEK), the structural components of which are often connected with high efficiency and reliability by induction welding. As a non-contact connection technology, the induction welding has the outstanding advantages of accurate energy input, strong process flexibility and the like. However, the heat generation mechanism of induction welding is complex and multi-source. For laminated composites, heat generation mainly results from three parts, eddy current resistance heating in the carbon fibers, dielectric loss heating of the resin matrix at the ply junction, and contact resistance heating between the fiber-resin interfaces. The heat generating efficiency of the three mechanisms are mutually coupled, so that the temperature field distribution of a welding area is determined together, and the quality and the performance of the welding joint are directly influenced. In order to achieve accurate regulation of the welding temperature field, the quantitative contribution of each heat generation mechanism must first be cleared. The prior art discloses a quantitative calculation method for induction welding multi-machine heat production efficiency of thermoplastic composite materials with orthogonal layering (such as 0 DEG/90 ℃). The method can effectively separate and calculate the respective heat generation amount and the respective duty ratio of fiber heating, dielectric loss and contact resistance heating under a specific orthogonal layering by establishing a microscopic heat generation model and combining experiments. However, the core advantage of composite laminates is their designability, with ply angles (e.g., 0 °, ±30°, ±45°, ±60°, etc.) being key design variables for tuning their macroscopic mechanical and physical properties. In practical engineering, variable angle layering is widely adopted to meet complex load and functional requirements. Unfortunately, existing orthogonal-mat-based thermoanalytical models have limitations: 1. The model is "static" and "personalized" in that existing models do not embed the ply angle as a core variable in their theoretical framework. The calculation formula is only suitable for a specific layering angle (such as orthogonality) set during modeling, and once the layering angle is changed, the internal relation between key parameters (such as node dielectric loss resistance, effective contact area and the like) and angles in the model cannot be embodied, so that the model cannot be directly popularized. 2. The existing method essentially needs to carry out complete modeling and experimental verification again when facing a new layering angle, and the process is complex and high in cost. This is essentially a "trial and error" mode, failing to provide a theoretical tool that can dynamically predict the heat generation mechanism duty cycle based on the mat angle. 3. The active design and optimization of the welding process are restricted, and the change rule of each heat generation mechanism under different layering angles cannot be known in advance and quantitatively, so that engineers are difficult to actively regulate and control the welding heat input through layering angle design in the structural design stage, and the capacity of realizing interface temperature field homogenization and welding joint performance optimization is limited. Therefore, developing a general calculation method capable of quantitatively reflecting the dynamic response relation between the layering angle and the efficiency of each heat generating mechanism becomes a key for breaking through the current induction welding process regulation bottleneck and realizing high-quality and high-efficiency connection of the composite material structure. Disclosure of Invention The technical problems to be solved are as follows: In order to avoid the defects of the prior art, the invention provides a dynamic calculation method for multi-machine heat production efficiency of variable-angle thermoplastic composite material induction welding, which is used for measuring the heat production quantity of different heat production mechanisms by respectively establishing quantitative relations for a plurality of heat production mechanisms in t