Aerospace Structural Integrity Engineering Services

Integrated Structural Risk

Structural Integrity Assessment 

Bring the available evidence together to determine what the structure can safely do and what action should follow.

Structural integrity questions rarely belong to a single discipline. A structure may have acceptable static margins while uncertainty remains about fatigue life, crack growth, test behavior, operating history, repairs, or the quality of the underlying assumptions. Evaluating these elements separately can leave the program without a coherent answer to the decision it actually faces.

Fidelis Aerospace integrates the relevant design, analysis, life, damage, test, inspection, usage, and configuration evidence into a unified assessment of structural adequacy and risk. The objective is to determine what the available evidence supports, identify what remains uncertain, and establish a technically defensible path forward.

• Review of intended function, structural requirements, operating environment, life objectives, and the decision the assessment must support.
• Integration of geometry, materials, loads, boundary conditions, load paths, stress response, deformation, stability, and strength margins.
• Evaluation of fatigue, durability, crack significance, crack growth, residual strength, damage tolerance, and inspection considerations where relevant.
• Consideration of test data, inspection findings, service history, repairs, modifications, exceedances, and configuration changes.
• Assessment of assumptions, data quality, model limitations, sensitivities, missing evidence, uncertainty, and confidence in the conclusions.
• Identification of governing conditions, structural risks, evidence gaps, and recommended actions.

Loads, Response, and Margins

Structural Analysis & Finite Element Analysis 

Understand how the structure carries load, which failure modes govern, and what margin exists.  

Reliable structural decisions begin with a clear understanding of load paths, boundary conditions, structural response, and credible failure modes. Fidelis combines classical analysis, engineering calculations, and finite element methods to establish that understanding and convert it into actionable design or program guidance.

The objective is not merely to produce stress contours. It is to create a verified analytical basis that explains structural behavior and supports a defensible decision.

• Load-path development, free-body diagrams, classical structural analysis, and preliminary sizing.
• Static strength, joints, fittings, sections, stability, buckling, local failure modes, and margins of safety.
• Linear static, contact, thermal-structural, and selected nonlinear or dynamic analyses when appropriate to the problem and available tools.
• Sensitivity studies, simulation-driven design iteration, structural optimization, and substantiation support.

Repeated Loading and Service Life

Fatigue Life & Durability Assessment 

Estimate how long a structure can operate under repeated loading and identify the conditions that control its life. 

A structure may satisfy static-strength requirements and still be vulnerable to fatigue under repeated service loading. Fidelis evaluates the relationship between local stress response, load spectra, material behavior, structural details, and cumulative damage to identify life-limiting locations and the factors that most strongly influence durability.

The resulting assessment can support design improvement, qualification planning, maintenance decisions, life-extension evaluations, and targeted testing.

• Stress-life and, where appropriate, strain-life fatigue assessment.
• Load-spectrum development, cycle counting, cumulative-damage evaluation, and usage sensitivity.
• Fatigue hotspot identification, local stress assessment, and comparison of competing design details.
• Life estimates, governing locations, uncertainty evaluation, and recommendations for redesign, testing, monitoring, or inspection.

Flaw Significance and Continued Capability

Fracture Mechanics & Damage Tolerance 

Determine what an existing or assumed flaw means for criticality, crack growth, residual strength, and inspection planning. 

Once a crack-like flaw is detected or assumed, the engineering question changes. Static margin alone is no longer sufficient. The assessment must consider whether the flaw is currently critical, how it may grow under future loading, how much residual strength remains, and what evidence is required to support continued operation or corrective action.

Fidelis applies fracture-mechanics and crack-growth methods to help teams understand flaw significance and establish a technically defensible response.

• Stress-intensity, fracture-criticality, and critical-flaw-size assessment.
• Fatigue crack-growth prediction under representative loading spectra.
• Residual-strength evaluation and sensitivity to geometry, loading, material properties, and initial flaw assumptions.
• Damage-tolerance substantiation and engineering support for inspection intervals, repair decisions, monitoring, or continued operation.

Prediction, Physical Evidence, and Root Cause

FEA Correlation, Test Support & Failure Investigation

Turn disagreement between prediction and physical evidence into a structured engineering investigation. 

When analysis does not match test, or when hardware exhibits an unexpected response, the discrepancy should not be resolved through arbitrary model adjustment. Loads, boundary conditions, fixtures, instrumentation, material behavior, geometry, assumptions, and potential failure mechanisms must be examined systematically.

Fidelis helps teams determine which explanations are physically credible, what the existing evidence supports, and what analysis, model refinement, testing, or inspection would most effectively reduce the uncertainty.

• Comparison of predicted and measured loads, strains, deflections, temperatures, modes, or failure locations.
• Review of model idealization, boundary conditions, interfaces, fixtures, instrumentation, material inputs, and test configuration.
• Sensitivity studies and evaluation of competing hypotheses for unexpected response, damage, or failure.
• Correlation findings, model-improvement recommendations, additional-evidence plans, failure-mechanism assessment, and corrective-action support.

Independent Judgment and Senior Support

Independent Technical Review & Structural Advisory

Strengthen critical structural decisions with an experienced, independent engineering perspective.

Programs do not always need another analysis model. They may need an experienced structural engineer to challenge assumptions, identify blind spots, evaluate the technical basis, prioritize risks, and help the team determine what should happen next.

Fidelis provides focused technical review and continuing structural advisory support for organizations that need senior expertise without creating a full-time specialist position. Engagements are outcome-focused and complement the client’s internal team rather than functioning as generic staff augmentation.

• Independent review of structural designs, analyses, finite element models, methods, assumptions, and substantiation packages.
• PDR, CDR, qualification, certification-support, or customer-review readiness assessments.
• Structural risk assessment, evidence-gap identification, finding prioritization, and closure planning.
• Fractional structural-integrity support, technical mentoring, analysis planning, and development of repeatable methods, calculations, or engineering workflows.

Design With Performance in Mind

Simulation-Driven Design

Use structural analysis to guide the design before late changes become expensive.

Simulation-driven design brings mechanics and analysis into concept development, preliminary sizing, and design iteration. Fidelis evaluates how candidate designs carry load, where critical behavior is likely to occur, and how geometry, materials, interfaces, and constraints influence performance.

The result is a stronger technical basis for selecting concepts, resolving design uncertainty, and advancing the hardware toward detailed analysis and substantiation.

• Concept screening and engineering trade studies
• Load-path development and preliminary structural sizing
• CAD-integrated analysis and iterative design refinement
• Documented assumptions, sensitivities, and design recommendations

When more detailed substantiation is required, the work can transition directly into structural analysis and finite element analysis.

Improve What Matters Most

Design Optimization

Refine an existing design to improve performance, mass, margins, or manufacturability.

Design optimization begins with the engineering decision—not an automated search for a mathematically ideal shape. Fidelis identifies the variables, constraints, and performance measures that matter; evaluates sensitivities and tradeoffs; and develops practical recommendations for improving the design.

The objective is a ranked and technically supported path forward rather than repeated trial and error. Proposed changes remain grounded in real interfaces, manufacturing constraints, program requirements, and the methods that will be used to verify the final design.

• Geometry, material, and configuration trade studies
• Mass, stiffness, strength, and structural-margin balancing
• Critical-feature and stress-concentration refinement
• Ranked design changes with documented effects and tradeoffs