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CN-121980703-A - Design method for single-sided repair of steel plate crack damage additive manufacturing

CN121980703ACN 121980703 ACN121980703 ACN 121980703ACN-121980703-A

Abstract

The invention relates to a design method for single-sided repair of a steel plate crack damage additive manufacturing, which comprises the steps of setting geometric and material parameters of a crack damage steel plate and a repair body, determining a load state to calculate Feng Misai-S stress distribution of the steel plate under an undamaged condition, then calculating the maximum standard semi-elliptical section of the repair body in a direction perpendicular to a crack direction based on the thickness, the strength ratio and the crack width of the steel plate, determining the whole length of the repair body along the crack direction according to the crack length, and finally calculating the variable section size distribution of the repair body along the crack direction according to a stress ratio function by combining the maximum standard section and the stress distribution to generate a semi-elliptical variable section three-dimensional repair body model matched with the internal stress of the steel plate. Compared with the prior art, the method solves the problems that the repairing body lacks a uniform geometric description model and is unreliable in calculation and design when the metal additive manufacturing is used for repairing the crack damage of the steel structure.

Inventors

  • YANG ZICHANG
  • LI GUOQIANG
  • JIAN XIAODONG

Assignees

  • 同济大学

Dates

Publication Date
20260505
Application Date
20260126

Claims (10)

  1. 1. The design method for single-sided repair of the steel plate crack damage additive manufacturing is characterized by comprising the following steps of: s1, setting geometric parameters and material parameters of a crack damage steel plate and material parameters of a repairing body, wherein the geometric parameters comprise the thickness of the steel plate, the crack length and the crack width, and the material parameters comprise the yield strength and the tensile strength of the steel plate and the yield strength and the tensile strength of the repairing body; S2, setting the load state of the crack damage steel plate based on the parameters set in the S1, and calculating Feng Misai S stress distribution in the steel plate under the condition of no damage; S3, calculating a maximum reference semi-elliptical section of the restoration body in a direction perpendicular to the crack according to the geometric parameters and the material parameters of the crack damage steel plate set in the S1, wherein the height semi-axis length of the maximum reference semi-elliptical section is calculated based on the thickness and the strength ratio of the steel plate, and the width semi-axis length is calculated based on the thickness, the strength ratio and the crack width of the steel plate; s4, calculating the overall length of the prosthesis along the crack direction according to the crack length in the S1; s5, calculating the cross-section size change distribution of the restoration body along the crack direction based on the maximum reference semi-elliptical cross section calculated in S3 and Feng Misai S stress distribution calculated in S2, and generating a design scheme by combining the whole length of the restoration body along the crack direction obtained in S4.
  2. 2. The design method for single-sided repair of steel plate crack damage additive manufacturing according to claim 1, wherein in S2, the Feng Misai S stress distribution is calculated by finite element or based on basic mechanics principle.
  3. 3. The design method for single-sided repair of steel plate crack damage additive manufacturing according to claim 2, wherein in S2, the Feng Misai S stress distribution inside the steel plate under the assumption of undamaged condition is calculated, having the process comprising: According to the set load state, when adopting elastic design, calculating elastic stress distribution based on the yield strength of the steel plate; When adopting plastic design, the plastic stress distribution is calculated based on the tensile strength of the steel plate, wherein the stress distribution is calculated by a finite element method or an analytic method according to the basic mechanical principle.
  4. 4. The design method for single-sided repair of steel plate crack damage additive manufacturing according to claim 1, wherein in S3, the height half-axis length of the maximum reference semi-elliptical section is specifically calculated by multiplying the product of the thickness and strength ratio of the steel plate by a first preset coefficient; the width half-axis length of the maximum reference semi-elliptical section is specifically calculated by multiplying the product of the thickness of the steel plate and the power of the strength ratio by a second preset coefficient and adding half of the crack width.
  5. 5. A design method for single sided repair of crack damage additive manufacturing of steel sheet according to claim 1, characterized in that in S3 the strength ratio is defined as the ratio of the yield strength of the steel sheet to the yield strength of the repair body in the case of elastic design and as the ratio of the tensile strength of the steel sheet to the tensile strength of the repair body in the case of plastic design.
  6. 6. The method for designing single-sided repair for steel plate crack damage additive manufacturing according to claim 1, wherein in S4, the overall length of the repair body along the crack direction is calculated according to the crack length in S1, and the specific process comprises the step of multiplying the crack length by a predetermined coefficient larger than 1 to obtain the overall length of the repair body.
  7. 7. The design method for single-sided repair of steel plate crack damage additive manufacturing according to claim 1, wherein in S5, based on the maximum reference semi-elliptical cross section calculated in S3 and the Feng Misai S stress distribution calculated in S2, the cross-sectional dimension variation distribution of the repair body along the crack direction is calculated, and the specific process includes: calculating stress ratios corresponding to the positions based on the local Feng Misai S stress and the maximum Feng Misai S stress at the positions of the crack direction obtained in the step S2, and limiting the minimum value of the stress ratios to be 0.6; And multiplying the stress ratio of each position by the height half-axis length and the width half-axis length of the maximum reference semi-elliptical cross section determined in S3 respectively to obtain the actual height half-axis length and the actual width half-axis length of the cross section at each corresponding position of the repairing body along the crack direction, thereby determining the continuous variation distribution rule of the cross section dimension.
  8. 8. The design method for single-sided repair of steel plate crack damage additive manufacturing according to claim 1, wherein in S5, the overall length of the repair body along the crack direction obtained in S4 is combined to generate a design scheme, and the specific process comprises: And constructing a semi-elliptical variable cross-section three-dimensional columnar structure model which extends along the crack direction and continuously changes in cross-section size according to the maximum reference semi-elliptical cross-section shape determined in the step S3, the cross-section size change rule calculated by the stress distribution obtained in the step S2 and the whole length determined in the step S4, wherein the model is the final design scheme.
  9. 9. The method according to claim 1, wherein in S5, a three-dimensional geometric model of the repairing body is finally generated, the three-dimensional geometric model is a semi-elliptic variable cross-section cylindrical structure extending along the crack direction, and the cross-section size of the three-dimensional geometric model continuously changes and matches with the internal stress distribution of the steel plate.
  10. 10. The design method for single-sided repair of steel plate crack damage additive manufacturing of claim 1, wherein the design method is used for a plurality of stress states and a plurality of structural conditions, wherein the plurality of stress states comprise at least one of uniform stress and gradient varying stress, and the plurality of structural conditions comprise at least one of tensile conditions and bending resistance conditions.

Description

Design method for single-sided repair of steel plate crack damage additive manufacturing Technical Field The invention relates to the field of steel structure damage repair and metal additive manufacturing, in particular to a design method for single-sided repair of steel plate crack damage additive manufacturing. Background The steel structure is susceptible to adverse factors such as fatigue load, corrosion action, accidental impact and the like in the long-term service process, so that local cracks or defects are generated. Such damage, if not repaired in time, can lead to reduced component load-carrying capacity and even compromise overall structural safety and durability. As described in the comparison document CN119622892a, the conventional crack propagation prediction method mainly depends on laboratory tests, empirical formulas and finite element analysis, and these methods have the problems that the laboratory tests cannot completely simulate the actual working environment, the prediction accuracy of the empirical formulas is limited by data representation, the calculation amount of the finite element analysis is large and time-consuming, and the like, so that the crack prediction is inaccurate, and the repair difficulty and uncertainty are further increased. The current common repairing methods comprise welding reinforcement, perforating unloading (crack stopping holes), steel plate pasting, carbon fiber reinforced composite material reinforcement and the like. Although the repairing technology is applied to engineering practice to a certain extent, the problems of poor geometric adaptability, insufficient site workability, low intelligent degree, difficult in-situ repairing and the like under complex cracks generally exist. With the development of metal additive manufacturing technology, the metal additive has high geometrical freedom degree, excellent material compatibility and in-situ forming capability, and provides a new solution for repairing crack damage of a steel structure. However, due to the fact that the metal additive manufacturing material is high in cost, how to improve the material utilization efficiency while guaranteeing the repairing effect becomes a difficult problem, meanwhile, the geometric freedom degree is high, the geometric design of the repairing member is still in an exploration stage although the possibility is provided for the repairing member to achieve complex surface morphology and design matched with the stress distribution of a crack area, a generalized three-dimensional unified geometric model is not formed yet, and a corresponding calculation formula and a design method are lacked, so that the application and popularization of the technology in engineering are restricted. Therefore, how to solve the problems that a prosthesis lacks a uniform geometric description model and calculation and design are unreliable when the metal additive manufacturing is used for repairing the crack damage of the steel structure becomes a key technical problem to be solved in the field. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides a design method for single-sided repair of steel plate crack damage additive manufacturing, which solves the problems that a repair body lacks a uniform geometric description model and is unreliable in calculation and design when the metal additive manufacturing repairs the crack damage of a steel structure. The aim of the invention can be achieved by the following technical scheme: The invention provides a design method for single-sided repair of steel plate crack damage additive manufacturing, which comprises the following steps: s1, setting geometric parameters and material parameters of a crack damage steel plate and material parameters of a repairing body, wherein the geometric parameters comprise the thickness of the steel plate, the crack length and the crack width, and the material parameters comprise the yield strength and the tensile strength of the steel plate and the yield strength and the tensile strength of the repairing body; S2, setting the load state of the crack damage steel plate based on the parameters set in the S1, and calculating Feng Misai S stress distribution in the steel plate under the condition of no damage; S3, calculating a maximum reference semi-elliptical section of the restoration body in a direction perpendicular to the crack according to the geometric parameters and the material parameters of the crack damage steel plate set in the S1, wherein the height semi-axis length of the maximum reference semi-elliptical section is calculated based on the thickness and the strength ratio of the steel plate, and the width semi-axis length is calculated based on the thickness, the strength ratio and the crack width of the steel plate; s4, calculating the overall length of the prosthesis along the crack direction according to the crack length in the S1; s5, calculating the cross-s