Library · Engineering & mechanics
What Friction & Wear Tribology got wrong, from 43 theses
Summary written by a model from the records below: The records evaluate tribological behaviors, contact modeling formulations, and frictional wear across diverse mechanical components, lubricants, and engineered coatings. Across these investigations, researchers encountered failures stemming from unmodeled friction dynamics, numerical solver instabilities, invalid analytical contact assumptions, and rapid material wear under sliding loads. These records come from graduate theses, 2021 to 2026, each labeled with its degree where the repository states it, and each links to its thesis. They were extracted by language models reading the full text, so treat each as a lead to read, not a verdict.
Plus 8 problems the authors left open, listed at the end.
Failure modes, by theses reporting them
Select a mode to jump to its records.
Analytical and empirical friction formulations fail to predict contact behavior under complex loading conditions
Classical friction assumptions such as constant friction coefficients, ideal brush models, and Amontons-Coulomb laws fail to capture non-linear tangential loads and contact pressure variations. Analytical contact models also produce non-physical parameter fittings, violate torque equilibrium, or fail to track friction drops near contact pitch points.
Tried and failed
analytical contact mechanics with empirical friction fitting applied to tapered roller bearing wedging calculations. Reason: friction coefficient fitted to non-physical negative values to match empirical manufacturer catalog ratings
Planetary Traction Drive for Submarine Application withTapered Rollers · MIT · Doctorate
Tried and failed
Benedict and Kelley friction coefficient model applied to gear contact friction prediction. Reason: Fails to capture coefficient of friction drop near the pitch point under high-speed elastohydrodynamic conditions
A new thermally coupled lubrication model for the prediction of transmission efficiency in electric vehicles · Imperial · PhD
Lost to a baseline
The detailed wedging friction model was beaten in fitting SKF bearing catalog calculation factor data by a simpler model omitting wedge friction and applying a direct efficiency factor (eta = 0.8, mu = 0.25).
Planetary Traction Drive for Submarine Application withTapered Rollers · MIT · Doctorate
Considered and rejected
Considered and rejected: Decided against constant friction models during gross slip in favor of wear-scar interaction models due to the observed non-constant friction force during gross slip.
Experimental characterization of frictional hysteresis for nonlinear dynamic analysis of jointed structures · Imperial · PhD
Considered and rejected
Considered and rejected: Rejected theoretical friction formula (sqrt(Fx^2 + Fy^2)/Fz) due to real tire deviations from ideal brush model behavior (variable pressure distribution, compliance, camber, residual forces).
Hybrid Friction Estimation based on Intelligent Tires and Vehicle Dynamics · Virginia Tech · Doctorate
Tried and failed
subtracting phase area without accounting for spreading applied to multiphase interface friction prediction. Outcome: did not generalise. Reason: neglecting dynamic spreading caused underestimation of effective coverage and overprediction of overall resistance
Multiscale Modeling of Frictional Behavior at Rough Contact Interfaces · EPFL · PhD
Tried and failed
Uniform crack slip state analytical assumptions applied to frictional microcrack hysteresis modeling. Outcome: did not generalise. Reason: Inhomogeneous crack states and non-sticking zones during unloading invalidated uniform forward/reverse slip assumptions
Micromechanical model for hysteresis in fluid-saturated porous rocks under hydrostatic loading · Imperial · Doctorate
Considered and rejected
Considered and rejected: Rejected relying solely on slider friction test measurements to represent tire-ice interaction, because slider tools ignore tire-specific normal load, tread inflation pressure, and rubber compound dynamics.
Experimental Characterization and Modeling of Tire-Ice Interface · Virginia Tech · Doctorate
Tried and failed
raceway control hypothesis for ball kinematics applied to rolling element bearing contact mechanics. Outcome: worse than baseline. Reason: violates friction torque equilibrium compared to virtual power minimization
Advances in contact mechanics and fluid dynamics for rolling contacts · Leibniz Universität Hannover · PhD
Tried and failed
Amontons-Coulomb friction model applied to untreated elastomeric polymer contact. Outcome: did not generalise. Reason: Tangential frictional force was non-linear with respect to normal force for raw elastomeric surfaces
Mechanics of Physical Knots: From Filaments in Contact to Surgical Suturing · EPFL · PhD
Numerical algorithms and state estimators suffer from instability and solver divergence when modeling friction
Contact algorithms and finite element simulations experience numerical instabilities, non-unique solutions, and joint luxation when integrating frictional contact laws. In addition, parameter estimation routines and filtering algorithms suffer divergence, high noise during traction loss, and discontinuities across multi-block cycles.
Considered and rejected
Considered and rejected: Rejected using a wet sliding friction coefficient of 0.2 with separating surface interactions in FE models because it caused numerical instability and complete joint luxation.
Overcorrected Implants for Total Shoulder Arthroplasty · EPFL · PhD
Considered and rejected
Considered and rejected: Rejected friction models based on bristle deflection due to complexity, discontinuous state variables, lack of velocity dependence, and computational inefficiency.
Non-smooth dynamics and sensitivity analysis of multibody systems with clearances and friction in differential variational inequality framework · Virginia Tech · Doctorate
Considered and rejected
Considered and rejected: Rejected standard statistical/empirical regression modeling for predicting friction from texture parameters due to small sample size and lack of physical interpretability.
CHARACTERIZATION AND MODELING DETERIORATION OF HIGH FRICTION SURFACE TREATMENT · Georgia Tech · PhD
Considered and rejected
Considered and rejected: Rejected making the heteroscedastic process noise model dependent on the latent friction parameter l because incorrect contact state estimates caused filter divergence.
Combining Learning and Structure for Robotic Manipulation · Tübingen · PhD
Tried and failed
lumped-parameter viscous radiation damping approximations applied to dynamic friction slider systems. Reason: fixed damping coefficients either eliminate or excessively overpredict dynamic stress overshoot
Mathematical and Computational Modeling of Injection-induced Seismicity · MIT · PhD
Tried and failed
standard least squares parameter estimation applied to friction and adhesion parameter estimation. Outcome: unstable. Reason: produced noisy, inconsistent estimates during sudden traction loss without dynamic filtering
Optimization approaches for high-performance and efficient utilization of redundancy in robotic systems · UT Austin · PhD
Lost to a baseline
Estimation of static friction coefficient using an averaged plain eversion model yielded 0.20, underestimating the force-sensor-measured baseline of 0.29 by 31%.
Modeling of Everted Tubes for Medical Applications · University of Washington · PhD
Considered and rejected
Considered and rejected: Slip-weakening friction rejected due to numerical discontinuities and piece-wise handling of healing across multi-block cycle simulations.
A practical dynamic earthquake cycle model as part of a physics-based seismic hazard analysis framework · Imperial · PhD
Considered and rejected
Considered and rejected: Rejected the analytical friction force derivative integration approach across the hysteresis cycle in favour of using the FFT algorithm on time-domain derivative signals, because the hysteresis cycle cannot be known a priori in real turbine applications.
Structural Dynamics Design of Steam Turbine Blades with Friction Contacts for Renewable Energy · Politecnico di Torino · PhD
Considered and rejected
Considered and rejected: Rejected standard constraint-based contact model (Trinkle et al.) due to failure to produce unique normal/frictional solutions upon initial collision
Modeling, Flight Control, and Estimation for Multi-UAV Cooperative Lift Systems · Georgia Tech · PhD
Unmodeled friction dynamics and interfacial slip severely degrade mechanical state estimation and control
Neglecting linkage compliance, internal actuator friction, or contact interface slip leads to large force prediction errors and significant reductions in system cutoff frequencies. Training control estimators on frictionless simulation data or ignoring thermal shifts in friction similarly causes severe estimation failures on physical hardware.
Tried and failed
kinematics-based series elastic actuator force modeling applied to robotic exoskeleton force estimation. Reason: unmodeled friction and compliance/deformations in mechanical linkages caused high force prediction errors
Vision-Based Force Planning and Voice-Based Human-Machine Interface of an Assistive Robotic Exoskeleton Glove for Brachial Plexus Injuries · Virginia Tech · Doctorate
Lost to a baseline
Experimental cutoff frequency for all printed beam designs on hardware was approximately half of the predicted simulation value due to unmodeled friction and sensor noise
Application of Co-Design Principles for Design of Series Elastic Joints · Virginia Tech · Doctorate
Tried and failed
training regression models on frictionless simulation data applied to mechanical stiffness estimation. Outcome: did not generalise. Reason: frictionless simulation failed to capture real-world friction dynamics leading to catastrophic evaluation errors
ULTRASONIC IMAGING AND TACTILE SENSING FOR ROBOTIC SYSTEMS · Georgia Tech · PhD
Lost to a baseline
Ideal PTO model matched input force better than the developed circuit model at higher driving frequencies (e.g. 3-4 Hz), where the circuit model overestimated force by ~17% due to unmodeled backlash and Stiction/Stribeck friction.
Model, Design, and Control for Power Conversion in Wave Energy Converter System · Virginia Tech · Doctorate
Considered and rejected
Considered and rejected: Rejected modeling joint lubrication and non-zero friction in FEA, retaining dry frictionless contact because wear depth is largely insensitive to friction coefficient and standard FE literature models dry contact.
Wear prediction in the acetabular component of hip implants · Texas Tech · Master's
Considered and rejected
Considered and rejected: Measuring torque indirectly via DC motor current and torque constant KT, rejected due to winding imperfections, model variations, and setup friction.
DESIGN AND IMPLEMENTATION OF AN MRI-COMPATIBLE MOTOR TEST STAND · Johns Hopkins · Master's
Considered and rejected
Considered and rejected: Rejected frictionless contact assumptions (zero shear traction) as neglecting shear interface transfer unrealistically inflates predicted lining utilization.
Tried and failed
extended Kalman filter wheel odometry fusion applied to mobile robot track navigation. Outcome: unstable. Reason: unmodeled variable frictional slip between drive wheels and contact surfaces degraded state estimation
A novel railway maintenance robot for inspection and repair · Cranfield · PhD
Considered and rejected
Considered and rejected: Rejected model-based oversteer/understeer detection in favor of fuzzy logic-based detection to maintain generality across different vehicle models without requiring precise tire/friction modeling.
Fortifying Cyber-Physical Systems through Comprehensive Bug-finding and Mitigation · Georgia Tech · PhD
Engineered surface coatings and textured materials experience mechanical breakdown and elevated friction
Surface treatments including controlled porosity, solid lubricant multilayers, and specialized thin films experience wear track collapse, spallation, and complete wear-through under sliding contact. These failures lead to stick-slip degradation, friction spikes, and higher wear rates than conventional monolithic alloys or untreated baselines.
Lost to a baseline
UHMWPE had higher friction coefficient against bovine cartilage (0.473 at 5 cycles and 0.776 at 600 cycles) than the hybrid/gyroid replacement device (0.133 at 5 cycles and 0.109 at 600 cycles).
Hybrid materials for meniscus replacement in the knee · Imperial · PhD
Tried and failed
introducing controlled surface porosity to reduce friction applied to metal alloy bearing sliding surfaces. Outcome: worse than baseline. Reason: porous surfaces suffered wear track collapse and increased friction coefficients under lubricated reciprocating contact
From defect to design feature: optimising LB-PBF-induced porosity for altering tribological behaviours of cocrmo surfaces for orthopaedic applications · Imperial · PhD
Lost to a baseline
Al2O3-4wt%ZrO2 had a higher wear rate (6.0426 x 10^-4 mm3/Nm) and higher friction coefficient (0.7478) than monolithic pure Al2O3 (wear rate 4.4408 x 10^-5 mm3/Nm, COF 0.5874).
Development, Processing and Characterization of Advanced Alumina Matrix Multi-material Nanocomposites Reinforced with Zirconia, Graphene and Carbon Nanotubes · York University · PhD
Lost to a baseline
Atmospheric plasma jet coating on upside-down mixed EUSD failed under tribological stress after ~70 cycles, degrading into stick-slip with high friction compared to commercial sliding varnish.
Einfluss der Wechselwirkungen auf die Substratanbindung von Atmosphärendruck-Plasmaschichten · Leibniz Universität Hannover · PhD
Tried and failed
anti-icing surface coatings applied to aerospace substrate de-icing. Reason: insufficient mechanical durability causing complete wear-through under dry sliding friction cycles
A Hybrid De-icing Strategy Utilizing Tailored Anti-Icing Coatings Paired with Electro-Thermal and Electro-Mechanical Ice Protection Systems for Use on Rotary-Wing Aircraft · Carleton University · PhD
Tried and failed
introducing surface porosity to reduce friction applied to metal surfaces under liquid lubrication. Outcome: worse than baseline. Reason: higher porosity increased the friction coefficient and wear volume loss rather than improving lubrication
From defect to design feature: optimising LB-PBF-induced porosity for altering tribological behaviours of cocrmo surfaces for orthopaedic applications · Imperial · PhD
Lost to a baseline
12 W Ta-DLC exhibited a higher coefficient of friction (0.26) than uncoated CoCrMo alloy (0.22) and undoped DLC (0.18).
Synthesis and characterization of Ta-DLC coatings over CoCrMo alloy · Saskatchewan · Master's
Lubricant formulations and mechanical friction interfaces suffer from additive depletion and thermal fading
Advanced lubricant strategies such as micellar surfactants and microencapsulated additives cause severe wear increases or experience sharp friction spikes once additive capsules deplete under shear. In addition, dry and boundary friction interfaces suffer friction curve instability, static friction collapse, and thermal fading under continuous loading.
Tried and failed
lubrication to reduce friction applied to metal cutting at intermediate speeds. Outcome: worse than baseline. Reason: increased dissipated energy by 7-8% and increased peak tool temperature by 13%
Coupled phenomena in thin layers · UT Austin · PhD
Lost to a baseline
Non-commercial formulations F-RH and F-RHT exhibited rather unstable friction coefficient curves compared to optimized commercial materials.
Particulate Matter Emission Issues in Brake Systems · University of Trento · PhD
Considered and rejected
Considered and rejected: Rejected reducing friction brake sizing based on regenerative braking capabilities due to thermal fading under track conditions.
Ein Beitrag zur konzeptionellen Auslegung eines elektrischen Sportwagens unter fahrdynamischen Aspekten · TU Wien · PhD
Considered and rejected
Considered and rejected: Boundary lubrication model as an explanation for lubricated rupture dynamics (rejected due to the significant drop observed in static/peak friction and fault strength)
Considered and rejected
Considered and rejected: Rejected downsizing mechanical friction brakes based on peak regenerative braking due to thermal fading risks on track and legal brake redundancy requirements.
Ein Beitrag zur konzeptionellen Auslegung eines elektrischen Sportwagens unter fahrdynamischen Aspekten · TU Wien · PhD
Tried and failed
micellar surfactant lubricant formulations applied to boundary lubrication and wear reduction. Outcome: worse than baseline. Reason: friction decreased but wear performance was orders of magnitude worse than standard oil lubrication
Biomimetic water-based lubrication: an exploration into vesicle lubrication · Imperial · Doctorate
Tried and failed
microencapsulated functional liquid additives applied to lubricating oil friction reduction. Outcome: unstable. Reason: friction spiked rapidly after small-diameter capsule fraction depleted under shear cycles
Design of ionic liquid based additives for integration with modern lubrication systems · UT Austin · PhD
Lost to a baseline
Empty DSPC liposomes had higher friction (0.093) and wear area compared to multi-lipid natural lecithin liposomes.
Biomimetic water-based lubrication: an exploration into vesicle lubrication · Imperial · Doctorate
Parasitic friction and frictional heating in mechanical bearings and drives cause major efficiency losses
Parasitic frictional drag in radial bearings, axial bearings, and roller cages causes major power loss and can reduce rotational speeds below operational thresholds. Frictional dissipation also generates thermal transients that distort torque measurements and prevents energy recovery devices from achieving expected efficiency gains.
Lost to a baseline
Prototype turbocharger overall efficiency lost to baseline conventional hydrodynamic bearing radial turbochargers due to high axial bearing friction (ηm ~90% vs 95-98%).
Einstufige Abgasturboaufladung von Pkw-Motoren mit Luftüberschuss für einen realtitätsnahen Fahrzyklus Single-Stage Turbocharging of Lean-Burn Passenger Car Engines for Real-World Driving Cycles · Leibniz Universität Hannover · PhD
Tried and failed
using sealed pre-lubricated bearings to isolate drag applied to mechanical transmission rundown torque measurements. Outcome: unstable. Reason: internal frictional heating caused thermal transients that distorted excess torque measurements and broke steady-state agreement
The role of lubricant viscosity in optimising electric vehicle transmission efficiency and reliability · Imperial · PhD
Lost to a baseline
Unbalanced sliding vane ERD prototype achieved only 17% power savings vs. 62% theoretically achievable by an ideal ERD due to 121 W frictional losses (48% in radial bearings).
Lost to a baseline
Gear mechanism fixed-recovery ERD did not decrease SEC below a standalone ideal pump without energy recovery due to tip slip and bearing friction.
Considered and rejected
Considered and rejected: Rejected off-the-shelf roller bearings as transmissions because transmission ratios were <= 3, were prelubricated with grease, and roller cages held elements on their OD which causes excessive friction losses.
Planetary Traction Drive for Submarine Application withTapered Rollers · MIT · Doctorate
Left open by the authors
Problems the authors named and did not get to.
Left open
Conduct a Latin Hypercube Monte-Carlo sensitivity study in Simscape incorporating translational joint compliance and friction for the folding aeroshell model. Blocker: Requires access to or recreation of the custom HATHOR Simscape multibody model developed in the thesis.
Left open
Calibrate the interactive friction model for other material-tool combinations using direct friction test data under machining loads. Blocker: Requires experimental direct friction testing apparatus and physical machining load data.
Machining informatics: A data guided research on interfacial tribology of machining · Imperial · PhD
Left open
Develop an algorithm modeling the friction coefficient's dependency on excitation frequency in wound electrical steel rotor press-fits. Blocker: Requires experimental tribological test rig data characterizing frequency-dependent friction coefficients between electrical steel laminations under vibrational/rotational excitation
Left open
Implement the calibrated interactive friction model into FEA software user-subroutines to enable dynamic tool life and wear prediction. Blocker: None
Machining informatics: A data guided research on interfacial tribology of machining · Imperial · PhD
Left open
Incorporate temperature dependence and inflection points into analytical viscosity-pressure models to predict viscometry directly from uncorrected friction data. Blocker: Requires uncorrected friction data from specific elastohydrodynamic contact experiments
Effect of polymers on lubricant rheology in an elastohydrodynamic contact · Imperial · PhD
Left open
Develop a performance model to predict the rate of pavement friction deterioration over time. Blocker: Requires longitudinal pavement friction and texture monitoring datasets over time which are not publicly available
A network-level statistical model for friction estimation in Texas · UT Austin · PhD
Left open
Reduce the number of texture clusters and simplify the regression equations used for estimating pavement Grip Number. Blocker: Requires original Texas pavement 2D laser profile and friction field dataset which is not publicly available.
A network-level statistical model for friction estimation in Texas · UT Austin · PhD
Left open
Characterize and validate the efficiency-factor bearing model against the friction wedging model for tapered roller planetary traction drives. Blocker: Requires a physical planetary traction drive test rig or empirical experimental data for validation.
Planetary Traction Drive for Submarine Application withTapered Rollers · MIT · Doctorate
Who has worked on this
Authors of the public theses cited on this page, most-cited first.
- Trevor Murphy · MIT · Doctorate · 2025
Planetary Traction Drive for Submarine Application withTapered Rollers - Qingyue Shi · Imperial · PhD · 2025
From defect to design feature: optimising LB-PBF-induced porosity for altering tribological behaviours of cocrmo surfaces for orthopaedic applications - Manoj Murali · Imperial · Doctorate · 2023
Biomimetic water-based lubrication: an exploration into vesicle lubrication - Mozammel Mia · Imperial · PhD · 2023
Machining informatics: A data guided research on interfacial tribology of machining - Hagen Werner Hölscher · TU Wien · PhD · 2023
Ein Beitrag zur konzeptionellen Auslegung eines elektrischen Sportwagens unter fahrdynamischen Aspekten - Sahil R. Shah · MIT · PhD · 2021
Making Decentralized Desalination More Affordable Using Improved Process Design, Control, and Energy Recovery - Parissa Sadat Alavi · EPFL · PhD · 2026
Multiscale Modeling of Frictional Behavior at Rough Contact Interfaces - ENIO COLONNA · Politecnico di Torino · PhD · 2026
Structural Dynamics Design of Steam Turbine Blades with Friction Contacts for Renewable Energy - Isaac James Pressgrove · Virginia Tech · Doctorate · 2026
Application of Co-Design Principles for Design of Series Elastic Joints - Christoph Küstner · Leibniz Universität Hannover · PhD · 2026
Einstufige Abgasturboaufladung von Pkw-Motoren mit Luftüberschuss für einen realtitätsnahen Fahrzyklus Single-Stage Turbocharging of Lean-Burn Passenger Car Engines for Real-World Driving Cycles - Alvin Biyoghé · Imperial · Doctorate · 2025
Micromechanical model for hysteresis in fluid-saturated porous rocks under hydrostatic loading - Josephine Kelley · Leibniz Universität Hannover · PhD · 2025
Advances in contact mechanics and fluid dynamics for rolling contacts
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