Graduate Aerospace Structures — 11-Part Assignment Series

Investigated the role of heat transfer in aerospace structures including launch vehicles, aircraft engines, and spacecraft thermal protection systems. Performed thermal simulations using Abaqus to analyze temperature distributions, thermal stress, and cyclic thermal fatigue in structural components subjected to extreme aerospace operating environments.

Analyzed Composite Overwrapped Pressure Vessels (COPVs) used in spaceflight applications including SpaceX Falcon 9 and NASA systems. Examined liner/wrapping construction, fiber winding patterns, and failure modes compared to metallic pressure vessels. Performed Abaqus structural simulations to evaluate hoop stress, burst pressure margins, and flaw sensitivity in COPV designs.

Studied structural buckling as a failure mode caused by excessive displacement and loss of stiffness under compressive loading. Examined shell sensitivity to geometric imperfections, thin-walled structures, and column buckling in aerospace-grade materials. Used Abaqus to run linear and nonlinear buckling simulations, extracting critical load factors and mode shapes.

Multi-part Abaqus CAE design problem series applying finite element methods to complex structural geometries. Developed mesh strategies, applied boundary conditions and loading scenarios, and post-processed von Mises stress, deformation, and strain energy results to evaluate structural performance and identify critical failure regions.

Performed visual fracture surface analysis to identify fatigue crack initiation, propagation, and final overload failure zones. Applied S-N curve methodology, stress concentration factors, and cyclic loading theory. Simulated fatigue life using Abaqus to predict crack growth under bending and torsional loading, correlating analytical predictions with observed failure morphology.

Analyzed metallic bellows — flexible expansion joints used across aerospace, propulsion, and thermal management systems including the Boeing 787 ECS, SpaceX Falcon 9 engine, and F-22 exhaust system. Performed Abaqus FEA to evaluate stress distributions, fatigue life, and pressure-flexibility tradeoffs in bellows subjected to high-temperature, high-pressure, and corrosive operating environments.

Applied NASA 5019A fracture control standards and NDE requirements to human-rated spaceflight hardware. Developed fracture control plans (FCP), classified fracture-critical components, and evaluated flaw tolerance using Linear Elastic Fracture Mechanics (LEFM). Computed stress intensity factors (K), critical crack sizes, and remaining life using Abaqus and NASGRO-based crack growth frameworks.

Investigated failure mechanisms in unvented honeycomb sandwich panels caused by entrapped air expansion during ascent and aeroheating. Analyzed facesheet-to-core adhesive disbonds, rupture loads, and the cascade failure mode unique to closed-cell honeycomb. Performed Abaqus simulations to quantify internal pressure buildup, peel stress at the facesheet-adhesive interface, and margin-of-safety under combined pressure and compression loading.

Analyzed bolted joint design for aerospace structural connections — covering imperial and metric fastener standards, preload requirements, joint stiffness ratios, and torque-tension relationships. Performed Abaqus contact simulations to evaluate bearing stress, shear-out, net section tension, and fastener load distribution in multi-fastener lap joint configurations.

Evaluated fusion and solid-state welding processes — plasma arc, arc welding, resistance spot welding, and friction welding — for aerospace structural applications. Performed Abaqus thermal-structural simulations to analyze heat-affected zones (HAZ), residual stresses, distortion, and fatigue life of welded joints under cyclic loading conditions representative of aerospace service.

Performed modal analysis to identify natural frequencies, mode shapes, and vibration response of aerospace structural components. Applied dynamic loading theory to piping systems, rocket engine attachments, and structural panels susceptible to resonance-driven fatigue. Used Abaqus CAE to extract eigenvalues, plot deformed mode shapes, and perform harmonic and transient response analyses under realistic launch vibration environments.