Stress, thermal, and fracture analysis and support of New Glenn stage 1 tank and tank internal and external mission and flight critical structure. Developed the analysis approach, primary enveloping loads, secondary loads, and a series of automation tools to allow rapid local tailoring and margin writing of orthogrid tank skin panels. Analyzing structure for tension, global and local buckling, crippling, vibration, and other criteria where appropriate using classical hand calculations and… Show more Stress, thermal, and fracture analysis and support of New Glenn stage 1 tank and tank internal and external mission and flight critical structure. Developed the analysis approach, primary enveloping loads, secondary loads, and a series of automation tools to allow rapid local tailoring and margin writing of orthogrid tank skin panels. Analyzing structure for tension, global and local buckling, crippling, vibration, and other criteria where appropriate using classical hand calculations and finite element analysis methods. Generating and validating global and local finite element models (FEMs). Thermal simulations integrated into structural design loop -extreme thermal environment of launch and reentry led to necessity to consider thermal for all aspects of the mission. Founding member of fracture control board for all of Blue Origin. Classification of parts as fracture critical. Generating fatigue spectra and completing damage tolerance analysis of fracture critical parts. Show less

Provides stress analysis of primary load carrying modifications. Analyzing primary structure for tension, buckling, crippling, vibration sensitivity, and other criteria where appropriate using classical hand and finite element analysis. Develops and validates global and local finite element models (FEMs). Chief damage tolerance engineer responsible for the development FDT repeated loads spectra, failure scenarios, path to certification and documentation for approval.

Led durability and damage tolerance structural analysis team. Determined representative flight segment exceedance spectra for aircraft usage. Developed a suite of tools to generate full flight-by-flight repeated loads spectra including mission profile development, mission mixing, mission randomization, and fatigue load or load factor spectrum. Fatigue spectrum tools build complete mission mix spectra with random mission mix, random max-min load pairing, PSD gust inclusion and random maneuver… Show more Led durability and damage tolerance structural analysis team. Determined representative flight segment exceedance spectra for aircraft usage. Developed a suite of tools to generate full flight-by-flight repeated loads spectra including mission profile development, mission mixing, mission randomization, and fatigue load or load factor spectrum. Fatigue spectrum tools build complete mission mix spectra with random mission mix, random max-min load pairing, PSD gust inclusion and random maneuver association, mission severity weighting, partial cycle conversion to full cycles (partial cycle binning), negative cycle handling, multivariate stress resultants, multiple load sources, and full cycle filtering and cycle counting. Show less

Durability and damage tolerance support for empennage structure certified to FAR 25.571; additional support on flight control systems. Developed detailed FEMs of the wing, vertical fin, and horizontal stabilizer. Identified critical locations for residual strength analysis and analyzed those locations using the modified crack closure integral (MCCI) technique. Determined durability and crack growth lives and inspection intervals for horizontal splice details. Developed many Femap macros to… Show more Durability and damage tolerance support for empennage structure certified to FAR 25.571; additional support on flight control systems. Developed detailed FEMs of the wing, vertical fin, and horizontal stabilizer. Identified critical locations for residual strength analysis and analyzed those locations using the modified crack closure integral (MCCI) technique. Determined durability and crack growth lives and inspection intervals for horizontal splice details. Developed many Femap macros to speed FEM development using the Femap API. Show less

Provided durability and damage tolerance support for continuing product development (CPD) of the Airbus A380 major wing structure. Developed and implemented a series of tools to streamline the implementation of a method for analyzing wing spars for the susceptibility to spanwise crack growth. Determined threshold and inspection intervals and crack initiation lives using maturing techniques for analysis of spanwise growing cracks in wing spars. Performed widespread survey of wing structure for… Show more Provided durability and damage tolerance support for continuing product development (CPD) of the Airbus A380 major wing structure. Developed and implemented a series of tools to streamline the implementation of a method for analyzing wing spars for the susceptibility to spanwise crack growth. Determined threshold and inspection intervals and crack initiation lives using maturing techniques for analysis of spanwise growing cracks in wing spars. Performed widespread survey of wing structure for sources of additional loads that would result in spanwise growing cracks not represented in the full-scale fatigue test. Developed modifications for major wing structure to address fatigue findings on full-scale test article. Show less

Provided durability and damage tolerance as well as stress support for broad portions of the clean sheet Scorpion airframe. In lieu of a defined flight profile mission mix the majority of the Scorpion airframe was evaluated using historically derived fatigue allowable stress levels. Determined the design and layout of many primary load paths and the identification of principal structural elements (PSEs). Evaluated all cockpit, canopy, main landing gear, nose landing gear, and flight control… Show more Provided durability and damage tolerance as well as stress support for broad portions of the clean sheet Scorpion airframe. In lieu of a defined flight profile mission mix the majority of the Scorpion airframe was evaluated using historically derived fatigue allowable stress levels. Determined the design and layout of many primary load paths and the identification of principal structural elements (PSEs). Evaluated all cockpit, canopy, main landing gear, nose landing gear, and flight control system details to ensure parts met fatigue allowable stress levels and were free of poor fatigue details. Developed novel isogrid-based pressure bulkhead that features robust damage tolerance capability. Led development of DADT flight profiles and created tools to allow spectrum development considering the special requirements of this program. Show less

Generated special mission profiles and developed spectra for potential Citation Mustang utilization scenario. Analyzed critical analysis locations to determine durability and crack growth lives and inspection intervals for special mission profiles. Provided durability and damage tolerance support for the Citation Longitude structure. Developed preliminary flight profiles for expected usage scenarios. Developed a suite of Femap macros for automating the creation of fastener elements in… Show more Generated special mission profiles and developed spectra for potential Citation Mustang utilization scenario. Analyzed critical analysis locations to determine durability and crack growth lives and inspection intervals for special mission profiles. Provided durability and damage tolerance support for the Citation Longitude structure. Developed preliminary flight profiles for expected usage scenarios. Developed a suite of Femap macros for automating the creation of fastener elements in detailed FEMs. The macros allow the choice of a number of different fastener representations and support bulk post-processing and tabulation of fastener output to determine shear and bearing margins of every modeled fastener automatically.Constructed matrix of tests to determine the applicability of traditional linear elastic fracture mechanics analysis techniques (LEFM) to the analysis of carbon fiber reinforced polymer (CFRP) structure. Supported unannounced CFRP related projects. Created laminate analysis tools for first ply and final ply progressive failure determination. Investigated effects of orthotropic material properties on fastener stiffness simulation. Show less

Provided durability and damage tolerance support for the Citation X+ empennage structure certified to FAR 25.571. Developed a method for utilizing Citation X flight strain survey data to produce spectra for the Citation X+ empennage. Generated spectra for each empennage analysis location. Determined durability and crack growth lives and inspection intervals for each fastener at points of major load transfer.

Provided durability and damage tolerance support for the Citation CJ4 empennage structure certified to FAR 23.571. Developed a detailed FEM of the empennage. Determined critical residual strength analysis locations and analyzed those locations using the MCCI technique. Assisted with development of utility to extract stress intensities from NASTRAN results. Determined durability and crack growth lives and inspection intervals for each fastener at points of major load transfer using preliminary… Show more Provided durability and damage tolerance support for the Citation CJ4 empennage structure certified to FAR 23.571. Developed a detailed FEM of the empennage. Determined critical residual strength analysis locations and analyzed those locations using the MCCI technique. Assisted with development of utility to extract stress intensities from NASTRAN results. Determined durability and crack growth lives and inspection intervals for each fastener at points of major load transfer using preliminary loads. Developed a Visual Basic macro that automates the creation of beam elements at fastener locations for finite element modeling.Correlated flight strain and test article gauge data to empennage FEM. Processed flight strain data in support of spectrum development. Determined durability and crack growth lives and inspection intervals for each fastener at points of major load transfer using final loads. Developed test plans and conducted tests to show residual strength capability of the empennage structure (either through multiple load paths or crack arrest/damage containment). Analyzed structure and conducted tests to show rotor burst residual strength capability. Show less

Performed stress analysis for the development of the 737-900ER. Generated stress notes for wing trailing edge structure. Updated legacy stress notes for model 900ER loads and communicated necessary changes to the design and manufacturing departments.

Performed design and stress engineering functions for the 737 model range. Developed CAD details for redesigned fuselage structures. Performed quick-response stress analysis for fleet sustainment liaison engineering.