In the design of offshore jacket foundations, fatigue life is crucial.
Post-weld treatment has been proposed to enhance the fatigue performance of
welded joints, where particularly high-frequency mechanical impact (HFMI)
treatment has been shown to improve fatigue performance significantly.
Automated HFMI treatment has improved quality assurance and can lead to
cost-effective design when combined with accurate fatigue life prediction.
However, the finite element method (FEM), commonly used for predicting fatigue
life in complex or multi-axial joints, relies on a basic CAD depiction of the
weld, failing to consider the actual weld geometry and defects. Including the
actual weld geometry in the FE model improves fatigue life prediction and
possible crack location prediction but requires a digital reconstruction of the
weld. Current digital reconstruction methods are time-consuming or require
specialised scanning equipment and potential component relocation. The proposed
framework instead uses an industrial manipulator combined with a line scanner
to integrate digital reconstruction as part of the automated HFMI treatment
setup. This approach applies standard image processing, simple filtering
techniques, and non-linear optimisation for aligning and merging overlapping
scans. A screened Poisson surface reconstruction finalises the 3D model to
create a meshed surface. The outcome is a generic, cost-effective, flexible,
and rapid method that enables generic digital reconstruction of welded parts,
aiding in component design, overall quality assurance, and documentation of the
HFMI treatment.

在离岸支架基础的设计中，疲劳寿命至关重要。提出了一种增强焊接接头疲劳性能的焊后处理方法，其中高频力学冲击（HFMI）处理被证明可以显著改善疲劳性能。自动化的 HFMI 处理提高了质量保证并在与精确的疲劳寿命预测相结合时可以带来成本效益的设计。然而，常用于预测复杂或多轴接头疲劳寿命的有限元方法（FEM）依赖于对焊缝的基本 CAD 描述，未能考虑实际的焊缝几何形状和缺陷。将实际的焊缝几何形状包含在有限元模型中可以改进疲劳寿命预测和可能的裂纹位置预测，但需要利用数字重建焊缝。目前的数字重建方法耗时或需要专门的扫描设备和零件重新定位。所提出的框架则使用工业机械臂和线扫描仪结合，将数字重建作为自动化 HFMI 处理装置的一部分。该方法应用标准图像处理、简单的滤波技术和非线性优化来对齐和合并重叠的扫描。筛选的泊松表面重构完成了三维模型以创建网格表面。其结果是一种通用、具有成本效益、灵活且快速的方法，可以实现焊接零部件的常规数字重建，有助于零件设计、整体质量保证和 HFMI 处理的文档化。

焊接组件的综合数字化重建：支持改进的疲劳寿命预测

Integrated Digital Reconstruction of Welded Components: Supporting  Improved Fatigue Life Prediction

Birnbaum and Saunders introduced a two-parameter lifetime distribution to
model fatigue life of a metal, subject to cyclic stress. Since then, extensive
work has been done on this model providing different interpretations,
constructions, generalizations, inferential methods, and extensions to
bivariate, multivariate and matrix-variate cases. More than two hundred papers
and one research monograph have already appeared describing all these aspects
and developments. In this paper, we provide a detailed review of all these
developments and at the same time indicate several open problems that could be
considered for further research.

本文详细回顾了二参数寿命分布模型的各种解释、推导方法、推广及扩展到双变量、多变量和矩阵变量情况，并指出了一些可供进一步研究的问题。