Inertia Welding Test Bar Ends to Turbomachinery Casing Sections

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Solution Overview

Problem

Conventional methods for manufacturing test bars from thin components like gas-turbine-engine casings face challenges due to insufficient material for large circular end portions, leading to inaccurate weldability and test data in materials testing.

Innovation Solution

A method involving obtaining a casing or spool section with a rectangular cross section, positioning it between semi-circular cylinders, inertia welding end extensions, and machining to create a test bar with a gage section and larger circular ends, ensuring accurate test data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional welding methods are used to attach end extensions to thin casing sections, then test bar manufacturing is possible, but weldability is poor and test data accuracy deteriorates

Engineering Contradiction:

Improvetest bar manufacturingVSAvoidweldability and test data accuracy

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces an intermediary inert atmosphere (nitrogen or argon gas) between the welding process and the environment. This mediator prevents oxidation and contamination during welding of thin casing sections, enabling reliable welds without compromising the integrity of the test bar or accuracy of test data.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If large circular end portions are machined from thin casing material, then conventional testing devices can be used, but insufficient material is available in thin components

Engineering Contradiction:

Improvecompatibility with conventional testing devicesVSAvoidmaterial availability in thin components

Core Design Contradiction:

Ease of operationVSQuantity of substance

Solution Approach 1:

The patent segments the test bar into distinct functional portions: the original thin casing section (providing the test specimen) and separately attached end extensions (providing the large circular end portions). This segmentation allows each part to fulfill its required function without requiring the thin casing to contain insufficient material for the entire assembly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent adds a longitudinal dimension to the thin casing section by attaching end extensions along its length. This dimensional extension transforms the originally insufficient thin section into an adequate test bar assembly with proper end portions for conventional testing device compatibility.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Quantity of substance

If the casing section is used directly as the test bar, then material is preserved, but the circular end portions required for conventional testing devices cannot be created

Engineering Contradiction:

Improvematerial preservationVSAvoidcompatibility with conventional testing devices

Core Design Contradiction:

Quantity of substanceVSEase of operation

Solution Approach 1:

The patent divides the test bar into the original casing section (preserved as-is to maintain material integrity and minimize waste) and separate end extensions (added to provide required geometry). This segmentation allows the casing section to be used directly without material removal while the extensions provide the necessary circular end portions for device compatibility.

Inventive Principle:

Principle #1Segmentation

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 allows for the production of test bars with accurate test data, overcoming the limitations of conventional weldability and material constraints, enabling effective material and dimension selection for components.

Implementation Method 1

Inertia welding the first end extension to the first assembly end and the second end extension to the second assembly end

Methodology Applied

Scientific EffectInertia welding: Friction Welding

Data Source

PatentUS7543378B2Method for manufacturing a test bar

Publication Date: 2009.06.09 GENERAL ELECTRIC CO

AI summary

nethod for manufacturing a test bar from a turbo-machinery component, test bar made in accordance with the method, and turbo-machinery component associated with the method. A component section is obtained from the turbo-machinery component, wherein the component section includes a component portion, and wherein the component portion has a substantially rectangular cross section and has a width. First and second semi-circular cylinders are obtained having a diameter substantially equal to the width of the component portion. The component section is disposed between, and in contact with, the first and second semi-circular cylinders defining a component-section-cylinder assembly having first and second assembly ends. First and second end extensions are obtained. The first end extension is inertia welded to the first assembly end and the second end extension is inertia welded to the second assembly end defining a test-bar stock. The test-bar stock is machined creating the test bar.