DFM Optimization for Military Drone Composite Wing Structure Manufacturing
Summary
General Dynamics Mission Systems achieved 49% reduction in manufacturing time and 97.8% structural integrity compliance for composite UAV wing assemblies through advanced resin transfer molding DFM optimization. The project eliminated secondary bonding operations while meeting MIL-STD-810 environmental requirements.
The Challenge
Initial Need:
General Dynamics' Pittsfield, Massachusetts advanced composites facility encountered critical production bottlenecks in their carbon fiber wing manufacturing operations for military unmanned aerial vehicle platforms, requiring complex multi-stage layup processes and extensive secondary bonding operations to achieve structural performance requirements under demanding military operating conditions. The original design comprised 127 individual carbon fiber prepreg plies.
Pain Points:
Complex layup sequences: 127 prepreg plies requiring 240 hours of skilled composite technician labor per wing assembly
Multiple autoclave cure cycles: 18 separate curing operations consuming 156 hours of autoclave capacity per wing
Secondary bonding requirements: 23 post-cure bonding operations adding $12,400 per wing in processing costs
Dimensional tolerance challenges: 19.3% of wings requiring rework to achieve ±0.5mm aerodynamic surface specifications
Our Solution
Our Approach:
The DFM optimization strategy focused on integrated resin transfer molding processes consolidating multiple manufacturing steps, optimized fiber preform design eliminating secondary bonding requirements, and strategic integration of metallic inserts during initial molding operations rather than post-cure installation. The engineering team implemented comprehensive computational fluid dynamics analysis using ANSYS Fluent.
Methodology:
Engineers utilized RTM-Worx process simulation software to analyze resin flow behavior, fiber preform deformation, and cure optimization across 14 different tooling design iterations. Advanced tooling design incorporated heated aluminum molds with conformal heating elements, enabling precise temperature control and achieving glass transition temperature of 210°C.
Final Summary:
The optimized wing design consolidated 127 prepreg plies into 89 dry fiber preform layers processed through single RTM operation, eliminated 20 of 23 secondary bonding operations through co-cured insert integration, and achieved ±0.3mm dimensional accuracy directly from molding operations exceeding original specifications by 40%. Manufacturing cycle time decreased from 240 to 122 hours.
Execution
Process Description:
Implementation required extensive structural validation including static testing per MIL-STD-810 Method 514.7 vibration requirements, environmental qualification testing through temperature cycling from -65°F to +160°F, and comprehensive damage tolerance assessment using compression-after-impact testing per ASTM D7137. The project team coordinated with Hexcel Corporation's advanced materials division.
Outcome
Value Comparison:
The DFM optimization delivered extraordinary improvements in manufacturing efficiency and structural performance, generating $8.7M annual savings through reduced processing operations and improved production throughput. Direct labor cost reduction of $18,500 per wing through cycle time optimization contributed $5.9M annually based on 320-wing production volume.
Client Testimonial:
"This groundbreaking DFM optimization represents a quantum leap in military composite manufacturing, demonstrating how advanced materials processing can dramatically improve efficiency while exceeding stringent military performance requirements. The 49% reduction in manufacturing time combined with superior structural integrity fundamentally transformed our production capability."
- Colonel (Ret.) Patricia Martinez, Director of Advanced Manufacturing Engineering, General Dynamics Mission Systems Pittsfield Advanced Composites Center