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CN-121997651-A - Ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions

CN121997651ACN 121997651 ACN121997651 ACN 121997651ACN-121997651-A

Abstract

The invention discloses a ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions, which comprises the steps of constructing a full-size multi-physical-field simulation model, establishing a fluid computing environment considering solar radiation, loading temperature field data for structural calculation, simulating a nonlinear contact interference press-fitting process, and carrying out multidimensional quantitative evaluation on press-fitting failure risk by taking a press-fitting curve, a press-fitting contact area, energy consumption of the press-fitting process and cylindricity errors of the stern bearing after press-fitting as evaluation indexes. The method and the device realize quantitative evaluation of wind speed dynamic change on press-fit quality by dynamically applying the variable characteristics of real environment temperature and wind speed to the model as time-varying boundary conditions, realize precise loading of non-uniform radiation heat flow by arranging a solar radiation model and a DO radiation model in fluid calculation, accurately predict temperature field distribution of a stern shaft tube, and comprehensively identify various failure risks in the press-fit process by constructing a multidimensional quantitative evaluation system.

Inventors

  • DENG YIBIN
  • Shi Chonghao
  • ZHANG JUN

Assignees

  • 武汉理工大学

Dates

Publication Date
20260508
Application Date
20260119

Claims (10)

  1. 1. The interference press-fitting quality prediction method for the ship stern bearing considering complex meteorological conditions is characterized by comprising the following steps of: S1, constructing a full-size multi-physical-field simulation model, namely, building a full-size three-dimensional geometric model comprising a stern bearing, a stern shaft tube and a guide cover assembly, and carrying out grid division; S2, establishing a fluid computing environment taking into account solar radiation, comprising: S2.1, constructing an air calculation domain of a fully-enclosed press-fit structure, and introducing a turbulence model for simulating flow separation and complex turbulence heat exchange effects around the guide cover; s2.2, calculating solar radiation and shielding; s2.3, loading a dynamic weather boundary; s3, loading temperature field data for structural calculation, wherein the method comprises the following steps: s3.1, carrying out unsteady flow and heat transfer calculation based on the calculation environment constructed in the step S2, and mapping the obtained transient and non-uniform temperature field of the structural surface in the fluid domain onto the nodes of the solid structural grid in real time through the fluid-solid coupling interface to serve as a heat load; s3.2, applying fixed constraint on the rear end of the stern tube, and solving transient thermal strain of the structure under nonuniform heating; s4, simulating a nonlinear contact interference press-fitting process, which comprises the following steps: S4.1, defining a friction contact pair between the outer surface of the stern bearing and the inner surface of the stern tube; S4.2, applying an axial displacement load to simulate a press-in process, drawing a press-in curve by calculating a branch counter force in the displacement direction, and obtaining a contact area and press-in energy consumption by solving a contact state; s5, taking the press-fitting curve, the press-fitting contact area, the energy consumption in the press-fitting process and the cylindricity error of the stern bearing after press-fitting as evaluation indexes, and carrying out multidimensional quantitative evaluation on the press-fitting failure risk.
  2. 2. The interference press-fitting quality prediction method for the ship stern bearing taking complex meteorological conditions into consideration is characterized in that in S1, a mixed grid strategy is adopted for grid division, structured grids are used in an air fluid domain of an enclosing structure for capturing details of air flow and heat exchange, boundary layer grids are divided in a fluid-solid coupling interface, and local grid encryption is carried out on an interference contact area of the stern bearing and a stern shaft tube in a solid structural domain so as to ensure calculation accuracy of contact stress and deformation.
  3. 3. The ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions as claimed in claim 1, wherein in S2.1, taking account of the fact that air flow in an open air environment has obvious unsteady characteristics, the macroscopic flow behavior of air is described by adopting a Reynolds average Navier-Stokes equation set as a control equation, and Realizable is introduced for strong reverse pressure gradient, streamline large curvature bending and flow separation phenomena existing around stern tube and guide cover curved surfaces And performing closed solving on the turbulence model.
  4. 4. The interference press-fitting quality prediction method for the ship stern bearing taking complex meteorological conditions into consideration is characterized in that in S2.2, the method for calculating solar radiation and shielding is characterized in that a solar calculator algorithm is utilized to automatically calculate a solar altitude angle and an azimuth angle according to longitude and latitude of an operation place and planned operation date and time to determine a solar incident vector, a discrete coordinate radiation model is adopted, a shadow judgment factor is automatically calculated through a ray detection function of the discrete coordinate radiation model, an illumination area and a shadow area formed on the surface of a stern shaft tube of a guide cover are accurately distinguished, and the accurate loading of non-uniform radiation heat flow is realized.
  5. 5. The method for predicting the interference press-fitting quality of the stern bearing of the ship taking complex meteorological conditions into consideration according to claim 1 is characterized in that in S2.3, the method for loading the dynamic meteorological boundary is that a curve of the change of the ambient temperature with time, which is actually measured or forecasted on the working day, and a wind speed-time curve are compiled through a user-defined function and are dynamically applied to a model as time-varying boundary conditions.
  6. 6. The ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions according to claim 1, wherein in S4.1, an augmentation lagrangian algorithm is adopted to process normal constraints of a contact interface so as to improve convergence.
  7. 7. The ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions according to claim 1 is characterized in that in S5, the press-fitting curve is evaluated by drawing a simulated press-fitting force-displacement curve, and if the curve exceeds an upper limit or has an abnormally steep slope, judging that the risk of "press-fitting" or "clamping stagnation" exists.
  8. 8. The ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions according to claim 1 is characterized in that in S5, the press-fitting contact area evaluation method is that based on a finite element post-processing result, the node contact state of a contact pair surface is extracted, the sum of effective coverage areas of all nodes in the contact state is calculated, and if abnormal fluctuation or local undersize occurs in the area, centering failure or local clearance is predicted.
  9. 9. The ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions, which is characterized by comprising the following steps of integrating a press-fitting force-displacement curve, calculating mechanical energy consumed in the whole press-fitting process, and indicating that excessive plastic shearing occurs to a contact surface microprotrusion body when the energy consumption is too high, wherein the potential abrasion risk exists in the S5.
  10. 10. The ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions according to claim 1 is characterized in that in S5, the assessment method of the stern bearing cylindricity error after press-fitting is that node coordinates of the inner surface of the stern bearing after press-fitting are extracted, cylindricity error is calculated based on a least square circle method, and if the error exceeds a design permission threshold, it is judged that the assembled form and position tolerance does not meet the requirement, and the method is a high risk item.

Description

Ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions Technical Field The invention relates to the technical field of ship manufacturing, in particular to a prediction method for a stern bearing press-fit failure risk under an open air environment by considering environmental temperature, wind speed and solar radiation multi-physical field coupling. Background The press mounting of the ship stern bearing is a core key process in shafting installation, and the interference fit quality of the ship stern bearing directly determines the long-term running stability of the shafting. Currently, the stern bearing press-fitting operation of large ships is generally performed at an open-air slipway or dock. The existing press-fitting process guidance and risk assessment method have the following limitations: 1. the model is seriously simplified, and the actual working condition is separated, the existing method is mostly based on the fixed convection heat transfer coefficient or steady-state temperature field assumption, and the structure non-uniform and transient thermal deformation caused by solar radiation, transient wind speed and day-night temperature difference in the open air environment is completely ignored. 2. The key physical field coupling mechanism is lacking, and an accurate coupling model between meteorological environment (radiation and convection), structural thermal response and press mounting mechanical behavior cannot be established. Particularly, shielding effect of complex structures such as fairings and the like on the stern tube is neglected (obvious temperature difference exists between an illumination area and a shadow area), so that serious distortion is predicted for 'out-of-round' deformation of a key reference surface of the stern tube before press mounting. 3. The evaluation dimension is single, the risk identification is incomplete, the traditional evaluation mainly depends on a macroscopic press fitting force curve, the comprehensive quantitative evaluation on the effective contact area of a press fitting mating surface, the energy consumption in the press fitting process and the cylindricity error of a final stern bearing is lacked, and the hidden risks such as local clamping stagnation, fretting wear or form and position tolerance out-of-tolerance after assembly are difficult to identify. Therefore, these limitations make the prior art unable to accurately predict the press-fit quality under complex weather conditions, resulting in experience-dependent process window selection with higher risk of press-fit failure or quality hidden trouble. Therefore, there is a need in the art for a press-fit quality prediction method that can accurately simulate the coupling effects of real weather environments and perform multidimensional quantitative risk assessment. Disclosure of Invention The invention mainly aims to provide a ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions, which introduces a ship stern bearing press-fitting model considering environmental temperature, solar radiation and wind speed multiple physical fields, can accurately capture the real deformation condition of an open-air structure, and solves the problem that the traditional model cannot predict pipe orifice ovalization. A four-dimensional evaluation system comprising the press fitting force, the contact area, the energy consumption and the cylindricity error of the stern bearing is established, and the hidden risk which cannot be found by simply relying on the press fitting force can be identified. The technical scheme adopted by the invention is as follows: a ship stern bearing interference press-fitting quality prediction method considering complex meteorological conditions comprises the following steps: S1, constructing a full-size multi-physical-field simulation model, namely, building a full-size three-dimensional geometric model comprising a stern bearing, a stern shaft tube and a guide cover assembly, and carrying out grid division; S2, establishing a fluid computing environment taking into account solar radiation, comprising: S2.1, constructing an air calculation domain of a fully-enclosed press-fit structure, and introducing a turbulence model for simulating flow separation and complex turbulence heat exchange effects around the guide cover; s2.2, calculating solar radiation and shielding; s2.3, loading a dynamic weather boundary; s3, loading temperature field data for structural calculation, wherein the method comprises the following steps: s3.1, carrying out unsteady flow and heat transfer calculation based on the calculation environment constructed in the step S2, and mapping the obtained transient and non-uniform temperature field of the structural surface in the fluid domain onto the nodes of the solid structural grid in real time through the fluid-solid coupling interface t