Cold Spray Studs for Aircraft Harness Attachment
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Solution Overview
Problem
Conventional studs bonded to aircraft structural components using adhesives often lack sufficient bonding strength, especially on coated or curved surfaces, which can fail under load.
Innovation Solution
The method involves cold spraying powder particles onto a substrate to form a node, drilling a hole only into the node, and machining the node to create a stud with enhanced bonding strength, allowing for secure attachment of wire and hydraulic harnesses on aircraft structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional adhesives are used to bond studs to structural components, then the bonding process is simple, but the bonding strength is insufficient under load especially on coated or curved surfaces
Solution Approach 1:
The patent replaces the chemical bonding mechanism (adhesives) with a mechanical bonding mechanism (cold spray deposition). The cold spray process deposits metal particles that mechanically interlock with the substrate surface, providing superior bonding strength without relying on chemical adhesion. This mechanical approach resolves the contradiction by achieving high strength while maintaining process feasibility through automated deposition and drilling operations.
Solution Approach 2:
The patent changes the bonding mechanism from chemical (adhesive bonding) to physical/mechanical (cold spray deposition). By altering the fundamental parameter of bonding methodology and using controlled particle deposition at specific velocities and temperatures, the process achieves enhanced bond strength that overcomes the limitations of adhesive bonding on coated or curved surfaces.
2Reliability
If studs are bonded using adhesives, then the process is easier to implement, but reliability under load is compromised
Solution Approach 1:
The patent replaces chemical adhesive bonding with mechanical cold spray deposition and drilling. The mechanical interlocking of deposited particles with the substrate provides reliable bonding that is not dependent on surface chemistry or adhesive curing conditions. This substitution achieves high reliability while maintaining manufacturing ease through automated processes that are insensitive to surface variations.
Solution Approach 2:
The cold spray deposition is performed as a preliminary action before drilling. By first depositing a layer of material that bonds reliably to the substrate, the process ensures structural integrity before creating holes. This preliminary bonding action resolves the contradiction by establishing reliable attachment prior to subsequent manufacturing steps.
3Adaptability or versatility
If adhesive bonding is used for studs, then manufacturing is simpler, but the bond fails on curved surfaces
Solution Approach 1:
The patent replaces adhesive bonding with cold spray deposition, which uses kinetic energy of particles to achieve bonding. This mechanical approach is inherently adaptable to curved surfaces because the particle stream can conform to complex geometries, unlike adhesive applications that require precise surface preparation and curing control. The process achieves versatility across flat and curved surfaces while maintaining reasonable process complexity through automated deposition systems.
4Strength
If conventional adhesive bonding is used, then installation is easier, but bonding strength under load is insufficient
Solution Approach 1:
The patent replaces chemical adhesive bonding with mechanical cold spray deposition followed by drilling. The mechanical interlocking mechanism provides superior load-bearing capacity compared to adhesive bonding. While the process involves additional steps (deposition and drilling), the automated nature of cold spray equipment maintains operational ease, resolving the contradiction by achieving high strength without significantly compromising installation convenience.
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 provides studs with adhesion strengths up to 30,000 psi, preserves substrate integrity, and enables secure attachment on curved surfaces, surpassing conventional adhesive methods in bonding strength and durability.
Implementation Method 1
cold spraying a powder onto a substrate to form a node on the substrate
Implementation Method 2
WO 2014/116256 discloses a cold-spray additive manufacturing system for producing dense powdered metal systems
Data Source
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AI summary
Studs (140; 415), nodes (110; 410), and study assembly (200) systems formed by various methods are disclosed. Various disclosed methods include cold spraying a powder onto a substrate (120) to form a node (110; 410) on the substrate and drilling a hole (130) only into the node (110; 410). Various disclosed methods include cold spraying a powder onto a substrate (120) to form a node (110; 410) and machining the node (110; 410) to form a stud (140; 415).