Negative-Pressure Arc Welding Threshold Prediction by Magnetic Field
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Solution Overview
Problem
The uncertainty in determining the magnetic field parameter threshold for negative-pressure arc welding leads to inefficiencies and high costs in establishing negative-pressure arcs, as current methods require extensive experimentation and consume significant resources.
Innovation Solution
A method involving a numerical simulation approach is used to establish a mathematical model, calculate, and fit the negative-pressure threshold under various conditions, utilizing equations such as Navier-Stokes, heat transfer, and Maxwell's electromagnetic equations to determine the magnetic field parameter threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If extensive experiments are conducted to determine the magnetic field parameter threshold, then the accuracy of determining the threshold is improved, but the energy consumption, time cost, and capital cost increase significantly
Solution Approach 1:
The patent establishes a mathematical model of the negative-pressure arc welding process in advance, which includes control equations for mass conservation, momentum conservation, energy conservation, current continuity, and Ohm's law. This preliminary modeling allows the threshold to be determined through calculation rather than extensive experimentation, significantly reducing time cost while maintaining accuracy
Solution Approach 2:
The patent creates a virtual copy of the physical welding process through numerical simulation. By solving the control equations numerically under different conditions and fitting the results, the system obtains a threshold determination equation that replicates the behavior of actual welding without requiring repeated physical experiments
2Measurement precision
If extensive experiments are conducted to determine the magnetic field parameter threshold, then the accuracy of determining the threshold is improved, but the energy consumption increases significantly
Solution Approach 1:
The patent replaces the mechanical experimentation system with a computational system. Instead of conducting physical experiments that consume energy for equipment operation, material processing, and measurement, the system uses numerical computation to solve the mathematical model, dramatically reducing energy consumption while maintaining determination accuracy
3Manufacturing precision
If physical constraints are used to improve the sidewall flow phenomenon of the welding pool, then the welding quality is improved, but the flexibility in dealing with different welding situations deteriorates
Solution Approach 1:
The patent determines the magnetic field parameter threshold through mathematical modeling and numerical simulation, obtaining a quantitative relationship between welding parameters and the negative-pressure threshold. This allows flexible adjustment of welding parameters for different welding situations without physical constraints, maintaining both welding quality and adaptability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method accurately predicts the occurrence of negative-pressure arcs, improving the molten pool flow and welding quality, reducing defects, and providing guidance for negative-pressure arc welding processes.
Implementation Method 1
At present, the main means of forming a negative-pressure arc is an external longitudinal magnetic field
Implementation Method 2
solving the arc energy source term consisting of Joule heat, electron enthalpy transfer, and arc radiation loss according to: Q=J²/σ+Jeφc+KBTe ln(1+exp((φa-φc)/KB T))-Qrad where KB is Boltzmann constant; e is electron charge; T is temperature field of arc shape; Q is heat source term; Qrad is arc radiation loss; solving a momentum source term in the momentum conservation equation based on the arc self-induced magnetic flux density B, the current density J
Implementation Method 3
solving the arc energy source term consisting of Joule heat, electron enthalpy transfer, and arc radiation loss according to: Q=J²/σ+Jeφc+KBTe ln(1+exp((φa-φc)/KB T))-Qrad
Implementation Method 4
Qrad is arc radiation loss
Implementation Method 5
calculating potential and magnetic vector potential distribution according to current continuity equation and Ohm's law V=J/σ+A; solving current density J and magnetic flux density B of electric field E based on V and A according to equations: E=-grad(V)+jωA; J=σE; B=grad×A
Implementation Method 6
solving a momentum source term in the momentum conservation equation based on the arc self-induced magnetic flux density B, the current density J
Data Source
AI summary
The present disclosure provides a method for determining a magnetic field parameter threshold of negative-pressure arc (NPA) welding including the following steps: forming a control equation using the Navier-Stokes equation, heat transfer equation, and Maxwell's electromagnetic equation; establishing a geometric model and meshing; setting material parameters; setting initial conditions and boundary conditions; conducting parameterized scanning, setting solver, collecting NPA data, and fitting NPA function; afterwards, performing numerical simulation calculation of NPA under different conditions, and then fitting the calculated NPA threshold data, such that the equation for determining the magnetic field parameter threshold of NPA welding can be obtained. The method may more accurately predict the threshold condition of NPA welding and provide guidance for NPA welding technology; and solving the instability of the molten pool caused by gravity and arc positive pressure during conventional positive pressure arc thin-wall surfacing, additive manufacturing, and inclined welding process.