1,721,140 research outputs found
Preface Proceedings of ITS-IFToMM 2024 5th International Tribology Symposium of IFToMM
No full textThis book presents the proceedings of the 5th International Tribology Symposium of IFToMM (ITS-IFToMM 2024), held in Salerno, Italy, on May 6th-8th, 2024, jointly with the 9th AIT (Italian Tribology Association) Workshop “Tribology and Industry”. It includes peer-reviewed papers on the latest advances in tribology, discussing topics such as friction, wear, lubrication, lubricants, biotribology, tribomaterials, solid lubricants, surface engineering, tribotesting, tribological design and optimization of machine components, modeling in tribology, contact mechanics, micro/nanotribology, tribology in power generating systems, metal working tribology, tribology in road transport and tribology in medicine. A valuable, up-to-date resource, it offers an essential overview of the subject for scientists and practitioners alike and inspires further investigations and research
Synovial Lubrication Modeling of Total Hip Replacements Using Musculoskeletal Multibody Dynamics
No full textNowadays the biotribology of the human articulations is a challenging topic in the framework of biomechanics research. A human synovial joint is a complex tribological system which is able to minimize friction and wear of the articulated cartilage surfaces, thanks to the mix of particular natural lubrication regimes which are established within the synovial membrane. Mainly due to the aging process, the cartilage covering the bones linked by the synovial joint tends to deteriorate, causing direct bone-to-bone contact and joint wear: the synovial joint diseases are responsible for loss of mobility, pain and tissues’ inflammation. The replacement of the worn natural joint with a prosthesis is actually needed, so a detailed tribological analysis of the artificial implant has to be conducted in order to predict the artificial joint wear and to maximize its duration.
While the in vitro approach is obviously reliable because it is based on experimental tests, the in-silico analysis is surely cheaper but it needs a deep and detailed mathematical and physical description of the analysed phenomena.
In this chapter the works produced by the authors are presented and the biotribology of the total hip replacements is discussed. In particular, once the numerical modelling of the synovial mixed elasto-hydrodynamic lubrication referred to the artificial hip joint is analysed, the influence of the joint configuration in terms of load and relative motion on its tribological state is introduced as the output of a pure mechanical problem associated with the human musculoskeletal system. The kinematics of the musculoskeletal system plays a key role within the joint tribological analysis, because it defines its dynamical behaviour and, in dependence on the muscular actions, generates the joint reactions which couple the articulations and affect its lubrication/contact state.
A multibody model of the human lower limb is shown and the inverse dynamics of the system subjected to a particular kinematics is described and solved. The aim of this chapter is to propose an algorithm characterised by a direct workflow which starts from the musculoskeletal kinematics and, coupling the multibody and the lubrication models, leads to the calculation of interesting tribological quantities. The proposed approach can be established as a powerful in silico tool adaptable to a particular subject and to several kinematics, in order to analyse the artificial joint tribology of customized implants
Real contact area and friction: an overview of different approaches
No full textThe aim of this chapter is to show and analyze and discuss the results obtained by the Finite Element Model (FEM) in the calculation of the Real Contact Area (RCA) of rough contacts with the presence of friction which plays a key role in mechanical contacts, for its relationship with other variables such as adhesion, wear, etc. The results of the simulations were compared with the outcomes obtained from three consolidated statistical approaches found in scientific literature: the Kogut and Etsion; Cohen, Kligerman and Etsion; and Li, Etsion and Talke models. The investigated conformal coupling consists of rigid smooth plane against a rough deformable plane shaped by a series of hemispheres which represent the surface asperities. A total of 15 samples with different mechanical properties and arithmetical roughness values were considered. The results of the FEM model, obtained in hypothesis of absence of asperities interaction, were achieved in terms of RCA, contact pressure, asperities deformation
Squeaking in Total Hip Arthroplasty: a Scoping Review on a Biotribological Issue
No full textCeramic-on-ceramic bearings for total hip arthroplasty (THA) are considered to be the best choice to avoid problems such as osteolysis and wear, which are mainly caused by soft bearings. Recent concerns have been raised because of some clinical reports on the presence of audible noise (squeaking) in some ceramic-on-ceramic total hip replacements. The occurrence of squeaking in some patients is related to a complex of tribological and dynamical interactions in the prosthesis components. Such mechanisms include edge loading, stripe wear, impingement, synovial lubrication film ruptures, third body particles, ceramic fracture, and vibrational modes of the entire structure. The resonance of metallic parts can produce noise in the human audible frequencies range, hence the implant metallurgic composition, the design and the tribological behavior play a key role. The aim of this scoping review is to map and summarize the available scientific evidence on hip squeaking, highlighting the theoretical fundamentals on the genesis of the phenomenon with its causes and effects, the adopted numerical approaches together with in-situ experiments, results about squeaking analysis of total hip replacements listed in order of time so that it is easier follow the progress of science and the research future directions. Hence the scope is to provide a comprehensive but at the same time exhaustive document that could help researchers, students, etc. to study more deeply this field
Supplemental material - Interventional Minimally Invasive Treatments for Chronic Low Back Pain Caused by Lumbar Facet Joint Syndrome: A Systematic Review
No full textSupplemental material for Interventional Minimally Invasive Treatments for Chronic Low Back Pain Caused by Lumbar Facet Joint Syndrome: A Systematic Review by Luca Ambrosio, Gianluca Vadalà, Fabrizio Russo, Giuseppe Pascarella, Sergio De Salvatore, Giuseppe F. Papalia, Alessandro Ruggiero, Marta Di Folco, Massimiliano Carassiti, Rocco Papalia, and Vincenzo Denaro in Global Spine Journal</p
Supplemental material - Interventional Minimally Invasive Treatments for Chronic Low Back Pain Caused by Lumbar Facet Joint Syndrome: A Systematic Review
No full textSupplemental material for Interventional Minimally Invasive Treatments for Chronic Low Back Pain Caused by Lumbar Facet Joint Syndrome: A Systematic Review by Luca Ambrosio, Gianluca Vadalà, Fabrizio Russo, Giuseppe Pascarella, Sergio De Salvatore, Giuseppe F. Papalia, Alessandro Ruggiero, Marta Di Folco, Massimiliano Carassiti, Rocco Papalia, and Vincenzo Denaro in Global Spine Journal</p
Proceedings of ITS-IFToMM 2024
No full textThis book presents the proceedings of the 5th International Tribology Symposium of IFToMM (ITS-IFToMM 2024), held in Salerno, Italy, on May 6th-8th, 2024, jointly with the 9th AIT (Italian Tribology Association) Workshop “Tribology and Industry”. It includes peer-reviewed papers on the latest advances in tribology, discussing topics such as friction, wear, lubrication, lubricants, biotribology, tribomaterials, solid lubricants, surface engineering, tribotesting, tribological design and optimization of machine components, modeling in tribology, contact mechanics, micro/nanotribology, tribology in power generating systems, metal working tribology, tribology in road transport and tribology in medicine. A valuable, up-to-date resource, it offers an essential overview of the subject for scientists and practitioners alike and inspires further investigations and research
From Marker Trajectories to Muscular Activations: A Musculoskeletal Multibody Model Considering Compliant Tendon Behaviour
No full textIn this paper a recent development about the multibody modelling of musculoskeletal system is presented. The authors implemented two new routines in the already developed algorithm simulating the inverse dynamics of musculoskeletal systems able to elaborate the driving actions that lead the system to move with a known kinematics. The routines added to the algorithm were the inverse kinematics tool and the consideration of the tendon compliant behaviour: the first made the code able to elaborate the evolution of the system degrees of freedom starting from a set of marker trajectories, while the second allowed to consider the deformability of the tendons included in the muscle actuators. The upgraded model was tested on an upper limb musculoskeletal system available on the OpenSim® software and the results were shown and discussed, focusing on the comparison between the configurations of rigid/compliant tendon possibility. The positive outcomes and the adaptability of the developed code allowed the authors to consider the utilization of the algorithm in the framework of the biotribological assessment of artificial joint, like the total hip replacement implanted in the lower limb system
Tribocorrosive Analysis of Titanium Grade V in Different Biological Solutions
No full textThe tribocorrosion and especially the (bio)tribocorrosion has been spreading in medical community due to its direct effect on prosthesis life cycle. Indeed, the combined action of mechanical and chemical wear promotes the total volume loss compromising the stability and thus the success of the implant. In this regard, the manuscript has the scope of investigating the tribocorrosive response of Titanium Grade V alloy, coupled with an alumina sphere, in three biological solutions as the Ringer’s ones. In this regard, techniques such as potentiostatic, potentiodynamic, open circuit potential and so on, were adopted. The latter provided the basis for modelling the total wear meant as sum of chemical, mechanical and synergistic component. The results showed that the chemical composition of the solution had a great influence on volume loss as much as on the tribochemical variables like friction, current and potential. Besides, the synergistic component was correlated with friction coefficient by a linear trend with determination coefficient (R2) equals to 0.89. Lastly, the dominant wear mechanism was the abrasive one with presence of pitting corrosion. In fact the total material loss was essentially composed of mechanical and corrosion-induced mechanical wear
- …
