Course Representative Projects

Laboratory Testing and Analysis through GSA

Example: Engineering Support Services for the Naval Air Warfare Center Weapons Division

Jacobs provided engineering support services for weapon systems development for the Naval Air Warfare Systems Weapons Division (NAWCWD) at multiple on-site and off-site locations, with the focal point of operations at China Lake and Pt. Mugu, CA. Areas of support included systems engineering, test and evaluation, technical data support, configuration management, integrated logistics support, technical data management support, and management support services. Jacobs recently was awarded the ESS III re-bid which extends our support to NAWCWD to 13 years.

Engineering Services – Jacobs has effectively applied systems engineering principles to virtually every NAWCAD weapon system development effort over the last five years. We made maximum use of modeling and simulation tools to conduct trade-off studies and minimize cost. We also routinely provide rapid response engineering analysis as part of the developmental and operational testing activities conducted on various weapons and support systems in the Navy acquisition cycle.

Failure Analysis – At NAWCWD, these data include a global finite element model, structural load conditions, structural concept/ configuration, structural sizing, structural stiffness, flutter results, and mass properties of the structural elements. The task of designing an air vehicle capable of hypersonic velocities is a significant challenge, because the effects of a hypersonic environment are so great and complex. The Structural Module performs sub-optimization on the designated structure design and then provides improved structural design data back to an overarching system, which uses the data in conjunction with other subsystem data for overall vehicle optimization. Structural design improvements include optimum weight, size, and stiffness of the structure while maintaining material property constraints (stress/strain limits), volume and buckling constraints, modal frequency constraints, and displacement goals. The Structural Module uses off-the-shelf codes where possible, such as NASTRAN (SOL144, SOL145, and SOL200) for much of the analysis. We were responsible for the design, development, and implementation of the IHAT system that provides the structural subsystem data associated with the overall air vehicle.

Loads and Analysis – We performed structures and loads analyses on the High Speed ARM Demonstration (HSAD) vehicle aerodynamic control fins, modifications to the HARM launcher for use on HSAD for captive flight tests onboard the F/A-18, on the HSAD airframe with emphasis on the gas generator and rocket motor booster cases. We reviewed the structural analyses performed on the HARM launcher to determine the maximum weight limits for the HSAD vehicle during F/A-18 captive flight tests, and prepared a flight clearance package to obtain approval for captive carriage and launch of the HSAD vehicle from the F/A-18. We managed mass properties characteristics of the HSAD vehicle during the weapon development program, and provided oversight/review of an HSAD Inert Stores Structural Test Plan.
Independent Loads Analysis – Jacobs has performed weapon stores flight clearance support on a variety of missile including the HSAD missile and other HARM variants. Our personnel evaluated and provided recommendations regarding the accuracy, completeness and suitability of flight clearance data packages. This support requires personnel to be proficient in NAVAIR flight clearance processes and experienced in dealing with the NAVAIR 4.3 structural flight clearance approval process and ability to perform air vehicle analyses in support of flight clearance assessment. Jacobs personnel also developed procedures for the review of supporting structural flight clearance data.
Loads and Dynamics – Jacobs personnel performed flutter characteristic analyses (using aeroelastic stability guidelines) of MIL-M-8856B of the Lockheed Martin GBU-16 weapon during captive carriage on the AV-8B, F-14, and F/A-18 C/D aircraft. The analyses evaluated the weapon throughout carriage and release envelope specified in the weapon performance specification. Our personnel developed a complete finite element model (FEM) of the free-free GBU-16 weapon from existing component FEMs of the body, wings and fins. The overall weapon freefree model was modified to simulate the captive weapon and assembled into a captive carriage flutter analysis model that included the aircraft, pylon and rack. The Jacobs structural dynamics model provided mode shapes and frequencies for use in subsequent captive carriage flutter analyses. Jacobs personnel verified that the assembled free-free GBU-16 FEM adequately predicted the characteristics of the weapon when compared with measured results from the GFI ground vibration test (GVT) data. Modifications to the FEM were made to achieve correlation between the FEM and the GVT data. Validation data included comparisons of mode shapes, frequencies and complex frequency response functions. Jacobs personnel also verified that the captive carriage flutter analysis model, including aircraft pylon and rack, also adequately predicted the characteristics of the mounted weapon. Jacobs personnel performed carriage flutter analyses of the GBU-16 weapon in accordance with paragraph 3.12 of MIL-A-8591. This analysis included symmetric and anti-symmetric weapon vibration modes for the aircraft carriage and release flight envelope. Parametric variations of actuator free play, bending, and torsion stiffness were evaluated. We made recommendations regarding weapon suitability for captive carriage, and the sensitivity of the flutter margins to key design parameters were defined.