Aircraft Engine Component Testing Using Statistical Tolerance Ranges

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Solution Overview

Problem

Current methods for testing components, such as aircraft engine parts, are inefficient due to narrow tolerance ranges that lead to high manufacturing effort and low reliability, as they only check individual parameter values within specified ranges without considering statistical distributions.

Innovation Solution

A method that determines actual values of component parameters, calculates statistical parameters, and classifies components based on both individual and statistical parameter ranges to assess reliability and functionality, allowing for larger tolerances and reduced manufacturing effort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If narrow value ranges are specified for all component parameters to ensure required properties, then reliability is improved, but manufacturing effort increases

Engineering Contradiction:
ImprovereliabilityVSAvoidmanufacturing effort
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the parameter specification from fixed narrow tolerances to statistical parameter ranges (mean, standard deviation, skewness, kurtosis). This allows broader individual value ranges while maintaining reliability through statistical control, directly resolving the contradiction between reliability and manufacturing effort

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic statistical evaluation that adapts to the actual distribution of measured values. Instead of static fixed tolerances, the system dynamically assesses whether the statistical parameters fall within acceptable ranges, allowing flexibility in individual values while ensuring overall reliability

Inventive Principle:
Principle #15Dynamics

2Reliability

If narrow value ranges are specified for all component parameters, then functionality is ensured, but manufacturing cost increases

Engineering Contradiction:
ImprovefunctionalityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent transforms the acceptance criteria from fixed parameter ranges to statistical parameter ranges. This allows manufacturers to produce components with broader individual tolerances, reducing manufacturing cost while ensuring functionality through statistical validation that the component population meets required performance characteristics

Inventive Principle:
Principle #35Parameter changes

3Reliability

If statistical parameters are considered in addition to individual values, then reliability increases, but measurement precision requirements increase

Engineering Contradiction:
ImprovereliabilityVSAvoidmeasurement precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent merges individual value measurement with statistical parameter calculation into a unified evaluation process. By combining multiple individual measurements to derive statistical parameters (mean, standard deviation, skewness, kurtosis), the system achieves higher reliability through population-based assessment while the required precision for individual measurements remains practical

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3944041A1Component testing
Publication Date: 2022.01.26 MTU AERO ENGINES GMBH
  • EP3944041A1 patent drawingFigure 1~2
  • EP3944041A1 patent drawingFigure 3~4
  • EP3944041A1 patent drawing

AI summary

The present invention relates to a method for testing a component (10), in particular an aircraft engine, comprising the steps of: - determining (S20) an actual value of a first parameter of a first feature (11.1) of the component; - determining (S20) an actual value of the first parameter of at least one further feature (11.2, 11.10, 11.12) of the component; - determining (S30) a first statistical characteristic of these actual values ​​of the first parameter; and - classifying (S40, S50) the component on the basis of the first statistical characteristic and the actual values ​​of the first parameter, wherein the component is classified into a predetermined quality class (S45) if the first statistical characteristic lies outside a predetermined first characteristic range or at least one of these actual values ​​of the first parameter lies outside a predetermined first value range.