Langford Analytic · Knowledge Base
Turbomachinery Structural Analysis
Structural assessment of turbomachinery components and assemblies — blades, discs, shafts, casings, supports and interfaces — under the combined demands of centrifugal loading, pressure, temperature, vibration, fatigue, overspeed and extreme rotor events. This category addresses component-level integrity and the interaction of these loads in turbomachinery-specific configurations. General rotordynamics, fatigue methods and thermal methods remain in their own dedicated Knowledge domains. From fundamental rotating stress through blade and disc analysis, thermal response, vibration, fatigue, overspeed and extreme rotor events.
Turbomachinery Structural Fundamentals
Turbomachinery Structural Analysis FundamentalsStructural mechanics of turbomachinery hardware, linking speed, pressure, temperature, aerodynamic loading and vibration to stress, deformation, clearance, fatigue, creep and containment.Turbomachinery Structural Load CasesDefinition and combination of steady, transient, start-stop, overspeed, aerodynamic, thermal, vibratory and abnormal turbomachinery load cases for structural qualification and life.Turbomachinery Structural Load PathsHow centrifugal force, pressure, aerodynamic load, torque and support reactions flow through blades, roots, discs, shafts, bearings, casings and mounts.Rotating vs Stationary Structural ComponentsStructural differences between rotor and stator hardware, including load definition, reference frames, growth, thermal response, supports, interfaces, clearances and dynamic behaviour.Coupled Physics in TurbomachineryCoupled CFD, thermal, structural, contact and dynamic analysis in turbomachinery, including load mapping, thermo-mechanical growth, feedback, reduced-order coupling and verification.Turbomachinery Structural Analysis WorkflowEnd-to-end turbomachinery structural workflow from requirements and operating envelope through load definition, analytical checks, FEA, dynamics, life, clearance, verification and reporting.
Centrifugal Loading & Rotating Stress
Centrifugal Loading FundamentalsRotational body-force mechanics for blades, discs, rings and rotors, including angular velocity, radius, mass distribution, centrifugal force, speed-squared scaling and analytical verification.Stress in Rotating ComponentsStress fields in rotating blades, rings, discs, hubs and shafts, including radial and hoop stress, blade pull, bore concentration, multiaxial effects and interaction with thermal and mechanical loads.Rotational Body Loads in FEAPractical finite-element application of centrifugal and rotational body loads, including axis definition, angular velocity, density, cyclic models, pre-stress, boundaries, units and reaction verification.Radial Growth of Rotating ComponentsPrediction and interpretation of centrifugal and thermal radial growth in blades, discs, hubs and shafts, with emphasis on tip clearance, fits, seal gaps and coupled rotor-stator deformation.Effect of Speed on Rotating StressHow rotational speed changes centrifugal stress, growth, contact, stiffness, fatigue and overspeed margin, with practical speed-squared scaling and nonlinear exceptions.Rotating Component Free-Body & Equilibrium ChecksIndependent free-body and equilibrium checks for rotating-component FEA, including centrifugal resultant, sector loads, pressure forces, torque, moments, symmetry and speed-scaling verification.
Turbine & Compressor Blade Structural Analysis
Turbomachinery Blade Structural AnalysisIntegrated structural assessment of turbine and compressor blades under centrifugal, aerodynamic, thermal and vibratory loading, including roots, tips, clearances, fatigue and verification.Turbine Blade Centrifugal StressDistributed centrifugal stress in turbine and compressor blades, including mass distribution, radius, taper, shrouds, root load, speed scaling and independent FEA verification.Aerodynamic Loads on Turbomachinery BladesPressure and shear loading on turbine and compressor blades, including CFD force extraction, pressure mapping, bending and torsion, unsteady forcing and structural verification.Thermal Stress in Turbine BladesThermal stress and deformation in cooled turbine blades, including metal-temperature gradients, cooling passages, coatings, transient heat transfer, temperature-dependent properties and thermo-mechanical verification.Blade Root & Attachment StressStructural mechanics of blade-to-disc attachments, including centrifugal load transfer, bearing and bending, contact, friction, fillets, fretting, tolerance, local FEA and fatigue.Fir-Tree Root Contact MechanicsNonlinear contact mechanics of fir-tree blade roots, including multi-flank load sharing, friction, seating, local pressure, fillet stress, tolerances, fretting and verification.Dovetail Blade AttachmentsStructural assessment of dovetail blade roots, including centrifugal seating, bearing and flank contact, bending, friction, edge loading, fillet stress, fretting and fatigue.Blade Tip Structural BehaviourBlade-tip growth, shroud mechanics, clearance, untwist, thermal distortion, tip rub and local stress, linking rotor deformation to stator geometry and dynamic behaviour.
Blade Material & Life Effects
Blade Material Behaviour at Operating TemperatureTemperature-dependent mechanical behaviour of turbomachinery blade materials, including modulus, yield, thermal expansion, fatigue, creep, anisotropy, coatings and material-data selection.Blade Creep & Long-Term DeformationCreep deformation and life of hot rotating blades under sustained centrifugal stress and temperature, including elongation, stress redistribution, rupture, clearance and creep-fatigue interaction.Blade Low-Cycle FatigueLow-cycle fatigue of turbomachinery blades driven by start-stop centrifugal and thermal cycles, including strain-life methods, mean stress, notch plasticity, mission counting and life verification.Blade High-Cycle FatigueHigh-cycle fatigue of turbomachinery blades under vibratory excitation, including pre-stressed modes, engine orders, resonance, forced response, damping, mean stress and fatigue life.
Discs, Rotors & Hubs
Turbine & Compressor Disc Structural AnalysisStructural assessment of turbine and compressor discs under centrifugal body force, blade pull, thermal gradients, bore and rim stress, attachment loading, growth, fatigue and overspeed.Rotating Disc Stress FundamentalsAnalytical and physical interpretation of radial and hoop stress in solid, annular and profiled rotating discs, with bore effects, thickness, blade pull and FEA verification.Disc Bore Stress & Stress ConcentrationDisc bore mechanics and local stress concentration from central holes, splines, keyways, fits and geometric transitions, including fatigue, plasticity and mesh treatment.Blade Pull & Rim LoadingTransfer of blade centrifugal force into disc rims, including sector loading, slot contact, circumferential distribution, local rim stress, blade-mass scatter and verification.Thermal Stress in Turbine DiscsThermal gradients and transient thermo-mechanical stress in turbine discs, including rim-to-bore temperature differences, startup/shutdown, material properties, growth and LCF interaction.Disc Low-Cycle FatigueLow-cycle fatigue of turbomachinery discs from start-stop centrifugal and thermal strain ranges, including bore and slot hotspots, strain-life, plasticity, mission usage and verification.Disc Creep & High-Temperature DeformationCreep and time-dependent deformation of high-temperature rotors and discs under sustained centrifugal stress, including bore/rim redistribution, growth, life and creep-fatigue interaction.Blisk Structural AnalysisStructural analysis of integrally bladed rotors, including blade-disc coupling, centrifugal and aerodynamic loads, local fillets, modal families, mistuning, repair effects and life.
Modal Response, Excitation & Resonance
Turbomachinery Blade Modal AnalysisPre-stressed modal analysis of rotating blades and bladed discs, including boundary conditions, centrifugal stiffening, temperature, contact, mode identification and test correlation.Centrifugal Stiffening of Rotating BladesHow rotational tensile pre-stress changes blade tangent stiffness and natural frequencies, including speed trends, thermal interaction, contact effects and pre-stressed modal verification.Engine Order ExcitationEngine-order forcing in rotating machinery, including shaft-order harmonics, vane and blade passing, spatial circumferential content, operating-speed mapping and resonance relevance.Campbell Diagrams for Turbomachinery ComponentsConstruction and interpretation of Campbell diagrams using speed-dependent modal frequencies and excitation orders, including crossings, mode tracking, operating ranges and test correlation.Blade Resonance AssessmentEngineering assessment of blade resonance combining frequency separation, excitation order, modal shape, damping, forced response, operating dwell and HCF acceptance.Forced Response of Turbomachinery BladesForced-response analysis of blades under harmonic aerodynamic excitation, including pre-stressed modes, modal forcing, phase, damping, alternating stress, resonance and validation.Mistuning in Bladed DiscsBlade-to-blade variability, mode localisation and forced-response amplification in bladed discs, including frequency scatter, reduced-order models, testing and robust HCF design.Cyclic Symmetry in Turbomachinery FEAUse of rotational periodicity and cyclic sectors for static, modal and harmonic turbomachinery analysis, including nodal diameter, harmonic decomposition, limitations and verification.
Extreme Rotor Events
Turbomachinery Overspeed AnalysisOverspeed assessment of rotating turbomachinery, including speed-squared centrifugal loading, plasticity, residual deformation, attachment and fit behaviour, clearance, proof testing and structural margin.Rotor Burst Structural AssessmentRotor burst mechanics and structural consequence assessment, including critical speed/capacity, fragment energy, failure modelling, casing interaction, uncertainty, test evidence and containment interfaces.Blade-Off Structural AnalysisStructural response to blade release, including sudden imbalance, rotor-bearing loads, shaft and casing response, transient interfaces, speed dependence, support reactions and event verification.Blade-Off Containment AssessmentContainment assessment for released turbomachinery blades, including threat definition, fragment kinematics, casing impact, nonlinear material response, secondary damage, mount loads and test correlation.Rotor-Stator Rub Structural ResponseStructural mechanics of rotor-stator rub, including contact initiation, friction, local heating, nonlinear force, vibration, wear, clearance evolution and assessment strategy.Tip Clearance & Structural GrowthSystem-level prediction of turbomachinery tip and seal clearances from rotor growth, casing thermal distortion, shaft/bearing movement, dynamics, tolerances and transient operating states.
Casings, Shafts & Support Structures
Turbomachinery Casing Structural AnalysisStructural analysis of turbomachinery casings under pressure, thermal gradients, bearing loads, split-line and flange effects, mounts, ovalisation, vibration, clearance and containment loads.Shaft Structural Stress in TurbomachineryStructural stress in turbomachinery shafts from torque, bending, axial thrust, fits, keyways and transient loads, with fatigue, thermal effects, critical-section assessment and verification.Bearing & Support Load TransferStructural transfer of radial, thrust and dynamic bearing loads into housings, casings and supports, including stiffness coupling, alignment, thermal effects and interface verification.Turbomachinery Mount & Interface LoadsMachine mount and foundation interface assessment under weight, torque, thrust, bearing reactions, thermal growth and fault loads, including support flexibility, preload, alignment and load transfer.
Integrated Analysis, Verification & Reporting
Turbomachinery Structural FEA VerificationSystematic verification of turbomachinery structural analysis, from mass, centrifugal loading and equilibrium through CFD/thermal mapping, contact, mesh convergence, modal response, nonlinear events, uncertainty, test correlation and configuration control.Defensible Turbomachinery Structural Analysis WorkflowEnd-to-end turbomachinery structural workflow from requirements and operating envelope through loads, model hierarchy, static and thermal response, dynamics, life, extreme events, clearance, verification, correlation and final engineering evidence.