A ship structure fatigue life assessment method and system based on spectral analysis theory

By combining the unit load method and spectral analysis theory, a finite element model was constructed and a stress response transfer function was synthesized, which solved the problem of low computational efficiency in fatigue life assessment of large ship structures and achieved efficient and accurate fatigue life assessment.

CN122113267APending Publication Date: 2026-05-29JIANGSU UNIV OF SCI & TECH
View PDF 0 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
JIANGSU UNIV OF SCI & TECH
Filing Date
2026-01-30
Publication Date
2026-05-29

AI Technical Summary

Technical Problem

Traditional methods for assessing the fatigue strength of ship structures suffer from low computational efficiency and insufficient accuracy. In particular, it is difficult to accurately assess fatigue life at critical nodes of complex structures such as large ore carriers and very large oil tankers. Existing direct calculation methods based on spectral analysis are time-consuming and require high hardware resources.

Method used

By combining the unit load method with spectral analysis theory, a coarse-grid finite element model of the entire ship and a refined model of the hot spot region are constructed. The stress response transfer function is synthesized using the principle of linear superposition. Combined with hydrodynamic analysis and material SN curves, the total cumulative fatigue damage of the ship within its design life is calculated.

Benefits of technology

This method enables efficient assessment of fatigue life of large ship structures, reduces computational redundancy and hardware resource consumption, improves the accuracy and reliability of fatigue life prediction, and solves the bottleneck of low computational efficiency in traditional methods.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN122113267A_ABST
    Figure CN122113267A_ABST
Patent Text Reader

Abstract

The application provides a ship structure fatigue life evaluation method and system based on spectrum analysis theory, first, basic data of a ship is acquired, a full-ship coarse-grid finite element model and a refined hotspot area finite element model are constructed; subsequently, a typical loading condition and target sea area wave environment parameters are determined, frequency domain hydrodynamic analysis is performed on the ship, and ship motion response and wave load transfer functions are obtained; on the basis, unit load method is adopted to exert discrete unit loads on the finite element model, stress influence coefficients of key nodes of the structure are solved and obtained; the wave load transfer functions and the stress influence coefficients are combined to obtain stress transfer functions; a generated wave encounter probability matrix is simulated, the stress transfer functions and a wave spectrum are combined to calculate stress response energy spectrum and each order spectrum moment; finally, stress response statistical characteristics are calculated based on the spectrum moments, total cumulative fatigue damage degrees are calculated by combining material S-N curves and Miner linear cumulative damage theory, so that evaluation on key node fatigue life is realized.
Need to check novelty before this filing date? Find Prior Art