Welding Control Using Spline-Based FE Nominal Stress Estimation
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Solution Overview
Problem
Conventional methods for estimating nominal stress in welded structures are time-consuming, error-prone, and often require arbitrary mesh density or specific geometric parameters, making them inefficient and unreliable.
Innovation Solution
A welding control system that uses finite element (FE) analysis algorithms to calculate stresses at multiple points along a base line of a welded structural component, spline-fits the stresses, identifies points with consistent second derivatives, and extrapolates these points to estimate nominal stress at the base point, thereby controlling welding process variables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional methods are used to estimate nominal stress (hand calculations with FE forces/moments, coarse FE mesh, or extrapolation based on geometric parameters), then the estimation can be obtained, but the process becomes time-consuming, error-prone, or arbitrary
Solution Approach 1:
The patent extracts the stress estimation process from conventional manual methods and coarse mesh approaches, instead using a refined FE mesh to directly calculate stresses at multiple points along a base line. This extraction allows automated processing while maintaining accuracy, eliminating the time-consuming nature of hand calculations and arbitrary coarse mesh methods
Solution Approach 2:
The patent implements feedback through automated algorithms that calculate stresses at multiple points, spline-fit the data, identify points with consistent second derivatives, and extrapolate to estimate nominal stress. This closed-loop automated process eliminates manual intervention, reducing both time and errors compared to conventional methods
2Reliability
If conventional methods are used to estimate nominal stress, then the estimation can be obtained, but the process becomes error-prone
Solution Approach 1:
The automated algorithm provides feedback validation by calculating stresses at multiple points, fitting splines, and identifying points where the second derivative is consistent (within threshold percentage). This self-validating process reduces errors by ensuring mathematical consistency in the stress distribution before extrapolation
Solution Approach 2:
The patent replaces manual calculation methods with automated computational algorithms. The computer-executable instructions automatically perform stress calculations, spline-fitting, second derivative analysis, and extrapolation, eliminating human error while maintaining or improving accuracy through systematic mathematical procedures
3Ease of manufacture
If coarse FE mesh is used to minimize local stress raising effects, then the calculation is simpler, but the approach becomes somewhat arbitrary or tedious
Solution Approach 1:
Instead of changing mesh density to a coarse level, the patent changes the approach by using a refined mesh with multiple calculation points along the base line. The algorithm then identifies points with consistent second derivatives and uses only those for extrapolation, providing a systematic non-arbitrary method that maintains reliability while achieving simplicity through automation
Data Source
AI summary
Systems and methods described herein are configured to control welding systems, for example, controlling welding process variables based at least in part on nominal stresses estimated using finite element (FE) algorithms. The systems and methods described herein may be utilized to identify nominal stress in welded structures and components to enable adjustment of welding process variables for the manufacture of subsequent welded structures and components, for example, performed by the same welding system. The systems and methods described herein also allow readily available FE stress results to be utilized in a consistent manner, as well as providing user feedback regarding the accuracy of the nominal stress approximations. Furthermore, the systems and methods described herein are generally faster and less error prone than conventional techniques, and are relatively insensitive to mesh density of the FE stress calculations.