Panel Structure Welding Sequence for Thermal Deformation Control

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Solution Overview

Problem

The existing methods for manufacturing panel structures face challenges in maintaining welding reliability due to thermal deformations and gaps formed between frames and face plates during the welding process, which decrease the overall reliability of the joint.

Innovation Solution

A method where the first frame is welded at a central position, and subsequent welding is performed sequentially towards both sides, allowing for continuous support and minimal deformation, ensuring consistent contact and reducing accumulated deformation through alternating welding patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If frames are welded discontinuously to portions between ribs on the face plate, then welding can be performed at multiple locations, but thermal deformation occurs at each welding portion and large clearance forms between ribs and frames, decreasing welding reliability

Engineering Contradiction:
Improvewelding speedVSAvoidwelding reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by heating the rear side of the weld zone ahead of the welding location using a torch. This pre-heating compensates for thermal deformation before welding occurs, preventing gap formation between the frame and face plate during discontinuous welding operations, thus maintaining welding reliability while enabling multi-location welding

Inventive Principle:
Principle #10Preliminary action

2Productivity

If welding is performed discontinuously from external sides toward the central part, then welding can be completed at all positions, but gaps form between welding positions and the face plate, and accumulated deformation occurs

Engineering Contradiction:
Improvewelding completionVSAvoidgap removal
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent inverts the conventional welding sequence by welding from the central part of the frame outward toward both ends. This reversal ensures that the face plate remains supported in a cantilevered manner throughout the process, preventing gap formation and reducing accumulated deformation. The central welding point serves as a stable reference that minimizes overall distortion

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If the face plate is pressed to the external welding position, then contact is achieved for welding, but the face plate deforms in a direction spaced away from the frame due to thermal influences

Engineering Contradiction:
Improvecontact consistencyVSAvoidface plate deformation
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent applies preliminary anti-action by pre-heating the rear side of the weld zone before welding. This pre-heating creates a thermal gradient that counteracts the deformation caused by subsequent welding heat, allowing the face plate to maintain contact with the frame during welding while minimizing thermal deformation. The pre-heating essentially prepares the material to resist the deforming forces that will follow

Inventive Principle:
Principle #9Preliminary anti-action

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 approach enhances welding reliability by maintaining consistent contact between the frame and face plate, minimizing thermal deformation, and allowing for easy removal of gaps, thereby improving the structural integrity of the panel structure.

Implementation Method 1

each of the welding portions is deformed by thermal influences

Methodology Applied
Scientific EffectThermal energy: Heating

Data Source

PatentEP2457684B1Method for manufacturing panel structure
Publication Date: 2018.03.07 MITSUBISHI HEAVY IND LTD
  • EP2457684B1 patent drawingFigure 1
  • EP2457684B1 patent drawingFigure 2~3
  • EP2457684B1 patent drawingFigure 4~5

AI summary

A method for manufacturing a panel structure in which a reference position of a first frame in an axial direction is first welded to one face of a face plate, a not-yet-welded position closest to the reference position in the axial direction is second welded to the one face, and welding is performed discontinuously to the one face from the not-yet-welded position closest to the reference position at portions on both sides in the axial direction on the basis of the reference position.