Composite Ply Failure Pattern for Kinetic Energy Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing containment structures for aircraft, spacecraft, and vehicular structures are inefficient in absorbing kinetic energy from impacts due to uncontrolled failure mechanisms and excessive weight, as they are typically made with single-type fibers in simple cross-plied layups, which do not effectively distribute load or absorb energy during impact events.
Innovation Solution
The method involves creating composite articles with strategically weakened fibers and matrix materials in designated patterns to absorb kinetic energy by plastically deforming and separating fibers, distributing load, and shearing the matrix, thereby controlling failure modes and reducing peak loads on individual fibers, allowing for more efficient energy absorption without increasing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional single-type fiber cross-plied layups are used for containment structures, then manufacturing is simple, but kinetic energy absorption efficiency is poor and weight is excessive
Solution Approach 1:
The containment structure is segmented into multiple plies with different fiber types, orientations, and properties. Each ply is designed to perform specific functions in the energy absorption sequence, creating a hierarchical structure that systematically manages kinetic energy through multiple failure modes including fiber breakage, matrix cracking, and delamination.
Solution Approach 2:
Different regions of the composite structure have locally optimized properties with specific fiber types (aramid, glass, carbon, basalt) and configurations tailored to their functional requirements. The structure transitions from stiff outer plies to more compliant inner plies, with each layer having locally optimized characteristics for its specific role in the impact response sequence.
2Strength
If more material is added to increase breach resistance, then strength increases, but weight increases
Solution Approach 1:
The structure employs multi-material composite construction combining four different fiber types (aramid, glass, carbon, and basalt fibers) with a thermoplastic matrix. This composite approach allows optimization of breach resistance through synergistic material combinations rather than simply increasing the quantity of a single material, achieving superior strength-to-weight ratio.
Solution Approach 2:
The invention optimizes breach resistance by carefully controlling structural parameters including ply thickness (0.5-2.0 mm total), fiber volume fractions (30-60%), and material property gradients through the thickness. These parameter optimizations enable achieving required breach resistance with minimized mass rather than through brute-force material addition.
3Strength
If fiber strength is increased to reduce breach risk, then breach resistance improves, but kinetic energy absorption capacity decreases
Solution Approach 1:
The structure employs a dynamic, multi-stage failure sequence where different plies fail at different times during impact. The aramid ply fails first to absorb initial energy, followed by matrix cracking and delamination, then glass fiber failure, and finally carbon/basalt ply failure as a backup. This dynamic progressive failure mechanism optimizes both breach resistance and energy absorption by distributing the energy dissipation process across multiple stages rather than requiring all fibers to fail simultaneously.
Solution Approach 2:
The design incorporates preliminary action by arranging plies in a specific sequence and orientation pattern that anticipates the impact loading direction and magnitude. The outer aramid ply is pre-positioned to fail first and absorb the initial shock, protecting the inner structural plies. This predetermined failure sequence is built into the structure before impact occurs, optimizing the energy absorption pathway.
4Ease of manufacture
If unidirectional fiber arrangements are used, then manufacturing is simplified, but load distribution during impact is uncontrolled
Solution Approach 1:
The fiber reinforcement is segmented into multiple unidirectional plies, each with fibers oriented in specific directions (0°, 90°, ±45°) relative to the impact axis. This segmentation allows each ply to carry load efficiently in its primary direction while the stack as a whole achieves controlled three-dimensional load distribution through the combination of oriented layers.
Solution Approach 2:
The invention transitions from two-dimensional in-plane load carrying to three-dimensional load distribution by stacking multiple unidirectional plies at different orientations. The through-thickness stacking of plies with varying fiber directions creates a 3D load path that controls and distributes impact forces more effectively than any single 2D arrangement could achieve alone.
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 the material efficiency of containment structures by directing failure along predetermined paths, increasing resistance to breaches while maintaining or reducing weight, effectively absorbing more kinetic energy and reducing the risk of structural breaches during impacts.
Implementation Method 1
separating the multiple substantially parallel fibers at the multiple lower strength length portions
Implementation Method 2
plastically deforming the ply and the matrix material
Implementation Method 3
the multiple substantially parallel split into multiple strands or ribbons, forming split ribbons from the multiple lower strength length portions
Implementation Method 4
shearing the matrix material around the split ribbons, between the ply and other plies of the composite article, or both
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A method of kinetic energy absorption using a composite article including: a ply (24) containing multiple substantially parallel fibers (22, 22a, 22b) having inherent failure strains and having inherent moduli; a matrix material at least partially encapsulating the ply; multiple lower strength length portions (24, 24a, 24b) distributed along individual fibers of the multiple fibers and having failure strains less than the inherent failure strains; and a designated pattern of the lower strength length portions distributed to selected locations identified in the ply. The method comprises distributing a load across the designated pattern when the ply receives a force from kinetic energy above a separation threshold by: plastically deforming the ply and the matrix material; separating the multiple fibers at the lower strength length portions; creating gaps (34, 34a, 34b) in the ply where the multiple fibers are separated, wherein the gaps separate along a longitudinal direction of the multiple fibers to form split ribbons from the lower strength portions; and shearing the matrix material around the split ribbons, between the ply and other plies of the article, or both.