Composite Coupon Testing for Combined Loading
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Solution Overview
Problem
Current methods for testing composite panels, such as full panel testing, computer simulation, and coupon testing, are costly, time-consuming, and lack accuracy, leading to inefficiencies in design optimization and certification processes.
Innovation Solution
A method involving modeling a composite panel with a notch, determining a combined stress state, and testing coupons under simultaneous shear and tension/compression forces to replicate panel conditions, allowing for the creation of a database for panel design and fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If full 5 stringer panels are tested, then certification accuracy is improved, but cost and time increase significantly
Solution Approach 1:
The patent divides the full panel testing into smaller coupon tests. By segmenting the panel into representative coupon sections and testing those individually under combined loading, the method achieves certification accuracy without the time and cost of testing entire panels.
Solution Approach 2:
The patent creates a simplified copy of the panel's critical stress regions through coupon models. These coupons replicate the essential structural characteristics and stress states of the full panel, allowing accurate prediction of panel behavior without testing the complete structure.
2Measurement precision
If full 5 stringer panels are tested, then certification accuracy is improved, but cost increases significantly
Solution Approach 1:
The patent segments the expensive full panel testing into cheaper coupon tests. By testing small representative coupons instead of entire panels, the method maintains certification accuracy while dramatically reducing material costs, fabrication expenses, and testing resources required.
Solution Approach 2:
The patent uses inexpensive coupon specimens as disposable test subjects. These small coupons can be fabricated cheaply and tested without the substantial investment required for full panels, enabling multiple test iterations at low cost.
3Loss of time
If computer modeling is used, then time is reduced, but accuracy deteriorates
Solution Approach 1:
The patent changes the loading parameters applied to coupons from traditional uniaxial loading to combined loading that replicates the complex stress states in actual panels. This parameter change enables coupons to provide accurate predictive data that computer models alone cannot achieve, while still maintaining rapid testing speeds.
4Loss of energy
If uniaxial coupon testing is used, then cost is reduced, but reliability deteriorates
Solution Approach 1:
The patent fundamentally changes the loading parameters from uniaxial to combined loading configurations. By applying multiple forces simultaneously at specific angles, the coupons experience stress states that match actual panel conditions, thereby achieving reliable performance predictions at low cost.
Solution Approach 2:
The patent transitions from one-dimensional uniaxial loading to multi-dimensional combined loading by applying forces in multiple directions simultaneously. This dimensional change in the loading approach enables coupons to capture complex failure modes and provide reliable predictions that match full panel behavior.
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 reduces costs and time while providing more accurate and reliable results compared to traditional methods, enabling faster and more efficient design optimization and certification of composite panels.
Implementation Method 1
modeling coupon stress states to replicate the combined stress state of the panel
Implementation Method 2
applying the first force (F1) and the second force (F2) simultaneously to the coupon
Data Source
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AI summary
A method for determining material failure that includes the steps of: fabricating a coupon (100) made of a material; applying first force (110) and second forces (120) on the coupon, where the second force (F2) is different than the first force (F2); and characterizing a material failure due to the application of the first force (F1) and the second force (F2) to the coupon.