CN-122020869-A - Three-parameter high-strength steel double-cell rolling tube section optimization design method

CN122020869ACN 122020869 ACN122020869 ACN 122020869ACN-122020869-A

Abstract

The invention provides a three-parameter high-strength steel double-cell rolling pipe section optimization design method, which is based on a traditional square section in a Chinese character 'ri' shape, and can systematically and continuously generate diversified sections comprising square, trapezoid, hexagon, indent hexagon and various mixed shapes on the premise of keeping the total height and the sealing area constant of the sections by introducing three shape parameters which influence the transverse bending crashworthiness of the double-cell rolling pipe, and by utilizing a multi-objective optimization algorithm, the optimal section parameter combination of specific energy absorption, peak force, maximum deformation and crushing force efficiency under the transverse bending condition is sought, so that clear theoretical guidance and design scheme are provided for the development of high-performance lightweight rolling sections.

Inventors

QIN PINPIN
SHI YIYUAN
HUANG JUNMING
Wu Linzhou
JIA FAN
MENG KAIYU
Ling Shangyuan

Assignees

广西大学

Dates

Publication Date: 20260512
Application Date: 20251119

Claims (7)

1. The cross section of the double-cell rolled tube before optimization is an initial square Chinese character 'ri', the initial square Chinese character 'ri' shaped cross section comprises an upper wing plate, a middle partition plate, a lower wing plate, two upper side walls and two lower side walls, wherein the upper wing plate, the middle partition plate and the lower wing plate are sequentially arranged at intervals along the vertical direction, the two upper side walls are respectively arranged on two opposite sides of the upper wing plate, each upper side wall is connected with the upper wing plate and the middle partition plate, the two lower side walls are respectively arranged on two opposite sides of the lower wing plate, each lower side wall is connected with the lower wing plate and the middle partition plate, and the upper side walls, the middle partition plate and the lower side walls are connected together to form a connecting point, and the method is characterized by comprising the following steps: S1, on the basis of the initial square Chinese character 'ri' shaped section, keeping the section height H and the section enclosed area unchanged, defining three shape parameters of offset distance o, upper offset angle alpha and lower offset angle beta to describe the section shape of the double-cell rolling tube, and generating sections with different shapes through the combination of different shape parameters, wherein the three shape parameters are defined as offset distance o, distance of a middle baffle plate from the middle position of the section along the vertical direction, upper offset angle alpha, deflection angle of the upper side wall relative to the vertical direction by taking a corresponding connection point as a rotation center, and lower offset angle beta, deflection angle of the lower side wall relative to the vertical direction by taking a corresponding connection point as a rotation center; S2, taking three shape parameters as section design variables of the double-cell rolling tube, selecting a specific energy absorption SEA, a peak crushing force PCF and a maximum deformation Disp for evaluating bending and crashworthiness of the double-cell rolling tube as optimization targets, and setting crushing force efficiency CFE more than or equal to 75% as constraint conditions, wherein the multi-target parameter optimization problem of the section of the double-cell rolling tube is defined as follows: S3, solving the multi-objective parameter optimization problem by adopting an optimization method based on a proxy model to obtain a Pareto front solution set considering specific energy absorption, peak force, maximum deformation and crushing force efficiency under the transverse bending condition; and S4, obtaining optimized values of the offset distance o, the upper side offset angle alpha and the lower side offset angle beta according to the Pareto front edge solution set, and determining the optimized cross section shape of the double-cell rolling tube according to the optimized values of the offset distance o, the upper side offset angle alpha and the lower side offset angle beta.
2. The method for optimizing the cross section of a three-parameter high-strength steel twin roll tube according to claim 1, wherein in step S1, the offset distance o is set to a positive value when the offset distance o is shifted upward, the offset distance o is set to a negative value when the offset distance o is shifted downward, 0 is set when the offset distance o is not shifted downward, positive values are set for the upper offset angle α and the lower offset angle β when the offset angle α and the lower offset angle β are deflected outward, negative values are set for the upper offset angle α and the lower offset angle β when the offset angle β is deflected inward, and 0 is set when the offset angle β is not deflected.
3. The method for optimizing the design of the cross section of the three-parameter high-strength steel twin-tube roll according to claim 2, wherein in the step S1, the method for generating the cross sections with different shapes by combining three shape parameters is as follows: In the initial square Chinese character 'ri' shaped section, the joint of one end of the upper wing plate and the top end of one upper side wall is set as a point A, the joint of the other end of the upper wing plate and the top end of the other upper side wall is set as a point B, the joint of the bottom end of one upper side wall, one end of the middle partition plate and the top end of one lower side wall is set as C, the joint of the bottom end of the other upper side wall, the other end of the middle partition plate and the top end of the other lower side wall is set as D, the joint of one end of the lower wing plate and the bottom end of one lower side wall is set as a point E, and the joint of the other end of the lower wing plate and the bottom end of the other lower side wall is set as a point F, the change of the shape parameters o, alpha and beta leads to the change of the lengths of two transverse edges AB and EF, namely the length and the cross-section sealing area of the upper wing plate and the lower wing plate, the position of the point A is adjusted to be the point after the change of the shape parameters o, alpha and beta The position of the point B is adjusted to be a point The position of the point C is adjusted to be the point The position of the point D is adjusted to be the point The position of the point E is adjusted to be a point The position of the point F is adjusted to be a point The cross-sectional closed area S becomes The calculation formulas of the lengths of the adjusted upper wing plate, the middle partition plate and the lower wing plate and the cross section sealing area are shown in formulas (1) - (4): wherein h is the height of the middle partition plate from the upper wing plate; In order to maintain the constant cross-section sealing area, the lengths of three transverse edges, namely the upper wing plate, the middle partition plate and the lower wing plate, are corrected by calculating an adjustment amount l according to the formula (5), and the lengths of the corrected transverse edges are shown in the formulas (6) - (8): after the shape parameters o, alpha and beta are determined, the lengths of the three transverse edges, namely the upper wing plate, the middle partition plate and the lower wing plate, are determined by combining the formulas (5) - (8), and then the lengths of the other side edges of the cross section of the double-cell rolled tube after optimization are determined.
4. The optimization design method for the cross section of the three-parameter high-strength steel double-cell roll pipe according to claim 1, wherein the step of solving the multi-objective parameter optimization problem by adopting an optimization method based on a proxy model in the step S3 comprises the following steps: s31, determining sample points by a full-factor test design method in a design space of shape parameters o, alpha and beta; S32, constructing a finite element model of a dynamic three-point bending impact simulation of a double-cell rolling tube based on the determined sample points, and solving to obtain maximum deformation Disp, specific energy absorption SEA, peak crushing force PCF and crushing force efficiency CFE corresponding to the sample points as target response values; s33, constructing a radial basis function proxy model according to the response value of the sample point, verifying the precision of the constructed radial basis function proxy model, and entering a step S34 if the precision meets the requirement, otherwise, adding the sample point to acquire more target response values to construct a new radial basis function proxy model until the precision of the constructed radial basis function proxy model meets the requirement; S34, substituting the constructed radial basis function proxy model into an NSGA-II algorithm to perform optimization, and obtaining a Pareto front solution set considering specific energy absorption, peak force, maximum deformation and crushing force efficiency.
5. The method for optimally designing the cross section of the three-parameter high-strength steel double-cell roll tube according to claim 4, wherein in the step S31, the levels of the shape parameters alpha and beta are set to 9, the levels of the shape parameter o are set to 5 to form a design space, 405 groups of sample points are uniformly selected in the design space, and then 45 groups of sample points are extracted from the 405 groups of sample points by adopting a random method for cross-validation of the constructed radial basis function proxy model.
6. The method for optimizing the design of the cross section of the three-parameter high-strength steel twin-tube roll according to claim 4, wherein in the step S33, the accuracy of the proxy model is evaluated by the goodness of fit R 2 , the root mean square error RMSE and the maximum relative error MARE, and the specific expression is: Where n is the number of sample points verified, And Finite element analysis results respectively representing the ith verified sample point and a proxy model predicted value corresponding to the ith verified sample point; Is that The closer R 2 is to 1, the better the fit of the proxy model, the smaller the values of RMSE and MARE, the more accurate the proxy model predictions.
7. The method for optimizing the cross section of a three-parameter high-strength steel twin-tube roll according to claim 4, wherein in the step S33, when R 2 is greater than 0.9 and RMSE and MARE are less than 0.2, the accuracy of the proxy model satisfies the requirement.

Description

Three-parameter high-strength steel double-cell rolling tube section optimization design method Technical Field The invention relates to the technical field of parameterized design of a cross section of a high-strength steel double-cell rolling pipe, in particular to an optimization design method of the cross section of a three-parameter high-strength steel double-cell rolling pipe. Background With the increasing strictness of global automotive industry on fuel economy, carbon emissions and crash safety requirements, the synergistic design of body weight reduction and high crashworthiness has become a core challenge in the current automotive engineering field. The high strength steel thin wall structure has become one of the key technical approaches to achieve the above objects by virtue of its excellent specific strength, good crashworthiness and significant cost advantages. In the forming process of the high-strength steel thin-wall structure, the application proportion of the rolling forming technology in the automobile industry is gradually increased due to the advantages of high efficiency, low cost and capability of manufacturing the closed section bar with the complex section. Among the numerous rolled profiles, a double-cell rolled tube (fig. 2) with a cross section in a shape of a Chinese character 'ri' is one of the most commonly used configurations at present due to its regular and symmetrical topological configuration and excellent bending and torsion resistance, and is applied to components bearing transverse bending collision loads, such as an anti-collision beam, a battery box body, a bus frame and the like. However, the current improvement of bending crashworthiness of the double-cell rolling tube with the cross section of the Chinese character 'ri' shape mainly depends on material upgrading (such as using higher strength steel types of DP980, DP1180 and the like) and optimization of tube wall thickness, and the systematic research on the design of the cross section shape is not enough, and the existing research is mainly limited to rectangular and square cross sections, which limits the further improvement of the bending performance to a great extent. Studies have now demonstrated that cross-sectional shape is a critical factor affecting the bending performance of thin-walled tubes, including the design of the external profile shape and the internal structure of the cross-section. In the aspect of external contour shape, the Tang et al （Tang T, Zhang W, Yin H, et al. Crushing analysis of thin-walled beams with various section geometries under lateral impact[J]. Thin Walled Structures, 2016, 102: 43-57） system compares bending performance of various simple sections such as round, elliptic, rectangular, trapezoid, cap-shaped and the like under lateral impact, and finds that the geometric parameters of the sections influence the bending performance to different degrees, and after Sookchanchai et al （Sookchanchai K, Hlaing S S, Uthaisangsuk V. A geometrical parametric study of side door reinforced beams under lateral impact load[J]. International Journal of Crashworthiness, 2022, 27(6): 1662-1677） compares side door anti-collision beams with round, U-shaped and W-shaped sections, the W-shaped section has better reinforcing potential. Studies on the aspect of the internal structure ,Albak （Albak E İ. Optimization for multi-cell thin-walled tubes under quasi-static three-point bending[J]. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2022, 44(5): 207） of the section show that the bending crashworthiness of the multicellular pipe can be effectively improved by designing internal reinforcing ribs with different shapes. In addition to the conventional configurations described above, some efficient configurations have been introduced into the cross-sectional design of thin-walled beams to further enhance their bending properties, including hexagonal, concave hexagonal and biomimetic configurations. Kahraman et al （Kahraman M F, İriç S, Genel K. Comparative failure behavior of metal honeycomb structures under bending: a finite element-based study[J]. Engineering Failure Analysis, 2024, 157: 107963） combine hexagons, concave hexagons, octagons with multicellular tubes, propose novel metal honeycomb tubes and compare their bending properties, and the results indicate that the specific energy absorption capacity of the concave hexagonal honeycomb tubes is highest. These studies show that the high-efficiency energy-absorbing cross-sectional shape can be applied to the thin-wall pipe structure, so that the bending crashworthiness of the thin-wall pipe structure can be remarkably improved. While the above studies demonstrate the effectiveness of certain cross-sectional shapes, they are mostly limited to comparative analysis of several preset, discrete configurations, which tend to ignore the "intermediate configuration" between typical shapes, which is more excellent. Meanwhile, f