Composite Plybook Definition With Variable Cured Thickness Compensation

Solution Overview

Problem

Existing methods for designing plybooks for composite components often result in manufactured parts that are larger or smaller than intended, necessitating costly and unreliable post-curing machining to correct thickness-related non-conformances.

Innovation Solution

A method that simulates composite material plies with variable cured ply thickness estimates based on local conditions, allowing for precise definition of plies to fill the component volume accurately, and compensates for thickness errors by defining an error compensation volume to ensure accurate manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a plybook is designed using automatic processes with constant cured ply thickness estimates, then the design process is efficient and fast, but the manufactured component deviates from the designed volume requiring post-curing machining

Engineering Contradiction:

Improveplybook design efficiencyVSAvoidcomponent thickness accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The method performs preliminary simulation of the curing process during the plybook design phase, estimating variable cured ply thickness for each ply before manufacturing. This preliminary action allows the design system to anticipate thickness variations and adjust the plybook accordingly, preventing the need for post-curing machining while maintaining efficient automated design processes

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention changes the parameter of cured ply thickness from a constant estimate to a variable estimate that accounts for local conditions during curing. By simulating different cured ply thickness values for different plies based on their specific conditions, the system achieves accurate volume prediction without sacrificing design efficiency, thus resolving the contradiction between productivity and manufacturing precision

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If post-curing machining is performed to correct thickness non-conformances, then component dimensional accuracy is improved, but manufacturing cost and time increase

Engineering Contradiction:

Improvecomponent dimensional accuracyVSAvoidpost-curing machining time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The method performs preliminary simulation of the curing process during the plybook design phase, estimating variable cured ply thickness for each ply before manufacturing. This preliminary action allows the design system to anticipate thickness variations and adjust the plybook accordingly, preventing the need for post-curing machining while maintaining efficient automated design processes

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The simulation system serves itself by using the estimated variable cured ply thickness to automatically adjust the plybook design without requiring external intervention or post-processing. The system corrects its own design predictions by incorporating curing shrinkage effects, eliminating the need for separate machining operations to achieve dimensional accuracy

Inventive Principle:

Principle #25Self-service

3Manufacturing precision

If post-curing machining is used to correct thickness variations, then component shape accuracy is improved, but manufacturing reliability decreases due to manual operations

Engineering Contradiction:

Improvecomponent shape accuracyVSAvoidmanufacturing process reliability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The invention replaces the mechanical machining process with a computational simulation and design adjustment process. Instead of using manual or automated machining to correct thickness variations, the system uses computer-based simulation to predict cured ply thickness and modifies the plybook design accordingly, substituting a reliable digital process for an unreliable manual mechanical process

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The simulation system serves itself by using the estimated variable cured ply thickness to automatically adjust the plybook design without requiring external intervention or post-processing. The system corrects its own design predictions by incorporating curing shrinkage effects, eliminating the need for separate machining operations to achieve dimensional accuracy

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS11059240B2Method of designing a plybook for a composite component

Publication Date: 2021.07.13 ROLLS ROYCE PLC

AI summary

Methods of designing a plybook for a composite component are disclosed. Included method comprising: defining a component volume corresponding to the composite component to be manufactured; defining a plurality of successive plies of composite material to fill the component volume; simulating at least some of the plurality of successive plies of composite material based on an estimate of variable cured ply thickness, wherein the variable cured ply thickness is estimated by: simulating at least a portion of a respective ply of composite material; and estimating a cured ply thickness for the portion of composite material at least partly based on local conditions of the portion. A plybook is defined based on the plurality of simulated plies.