ARE TIBIOFEMORAL COMPRESSIVE LOADS TRANSFERRED ONLY VIA CONTACT MECHANISMS?

2012 ◽  
Vol 12 (04) ◽  
pp. 1250071
Author(s):  
FERAS HAKKAK ◽  
MOSTAFA ROSTAMI ◽  
MOHAMAD PARNIANPOUR
Keyword(s):  
Bearing Capacity ◽  
Contact Stress ◽  
Contact Area ◽  
Daily Activities ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Tibiofemoral Joint ◽  
Body Weights ◽  
Compressive Loads ◽  
Joint Loads

The tibiofemoral joint is known to bear compressive loads of several body-weights during daily activities. These forces are known to be transferred through the joint via compression of the tibial and femoral surfaces against one another. The menisci are also known to enhance this process by increasing the contact area and decreasing contact stress. However, calculations presented in this paper suggest that the load-bearing capacity of contact mechanisms is seemingly several times smaller than tibiofemoral joint loads. This suggests that probably one or more non-contact load-bearing mechanism(s) exist, and share the load with the already known contact mechanisms.

scholarly journals EVALUATION OF AXIAL LOAD-BEARING CAPACITY OF CONCRETE COLUMNS STRENGTHENED BY A NEW SECTION ENLARGEMENT METHOD

2021 ◽  
Vol 0 (0) ◽  
pp. 1-14
Author(s):  
Meijing Hao ◽  
Wenzhong Zheng ◽  
Wei Chang
Keyword(s):  
Bearing Capacity ◽  
Axial Load ◽  
Large Scale ◽  
Prediction Models ◽  
Concrete Columns ◽  
High Accuracy ◽  
Confining Stress ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Compressive Loads

The objective of this study is to evaluate the axial load-bearing capacity of section-enlargement concrete columns. To reach the objection, a new strengthened method in which columns are jacketed with a large welded octagonal stirrup at the center and four spiral stirrups at the corners of column is developed. The new section-enlargement method avoids interrupting existing columns and improves the reliability of strengthened part, besides, the confining stress generated by octagonal stirrup and spiral stirrups enhances the compressive strength and deformability of strengthened columns. In addition, sixteen large-scale concrete columns strengthened by the new strengthened method were tested under axial compressive loads. The experimental results show that the axial compression ratio of existing column generates stressstrain lag in strengthened part and decreases the load-bearing capacity of specimens; the stirrups in strengthened part significantly enhance the axial load-bearing capacity of specimens. According to confinement conditions, the cross-section of specimens is divided into five parts and the confinement factor for each part is calculated to establish the prediction models for the load-bearing capacity of specimens. Furthermore, by comparing the results between the developed model and existing models, the developed model has high accuracy in evaluating the load-bearing capacity of strengthened columns.

A First Approach for the Treatment of Galvanic Corrosion and of Load-Bearing Capacity of Clinched Joints

2021 ◽  
Vol 883 ◽  
pp. 97-104
Author(s):  
Sven Harzheim ◽  
Christian Steinfelder ◽  
Thomas Wallmersperger ◽  
Alexander Brosius
Keyword(s):  
Finite Element ◽  
Contact Stress ◽  
Contact Area ◽  
Galvanic Corrosion ◽  
Element Model ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Short Period ◽  
Bearing Behavior ◽  
Joint Integrity

Corrosion is a major cause for the failure of metallic components in various branches of the industry. Depending on the corrosion severity, the time until failure of the component varies. On the contrary, a study has shown that certain riveted metal joints, exposed to a short period of mechanical loading and corrosion, have greater fatigue limits. This study gives rise to the question how different corrosion exposure times affect joint metallic components. In the present research, a theoretical approach is developed in order to evaluate the influence of galvanic corrosion on joint integrity of clinched metal joints. At first, the framework for modeling galvanic corrosion is introduced. Furthermore, a simulative investigation of a clinching point is carried out based on the assumption that corrosion leads to a reduction of the contact area which leads to a local increase in contact pressure. For this purpose, the stiffness values of individual elements in a finite element model are reduced locally in the contact area of the undercut and the contact stress along a path is evaluated. Summarizing, a modeling approach is introduced to investigate corrosion effects on load-bearing behavior of clinched joints.

Increased load bearing capacity of mechanically joined FRP/metal joints using a pin structured auxiliary joining element

2020 ◽  
Vol 62 (1) ◽  
pp. 55-60
Author(s):  
Per Heyser ◽  
Vadim Sartisson ◽  
Gerson Meschut ◽  
Marcel Droß ◽  
Klaus Dröder
Keyword(s):  
Bearing Capacity ◽  
Load Bearing Capacity ◽  
Load Bearing

Load-Bearing Capacity of Direct Inlay-Retained Fibre-reinforced Composite Fixed Partial Dentures with Different Cross-Sectional Pontic Design

2017 ◽  
Vol 68 (1) ◽  
pp. 94-100
Author(s):  
Oana Tanculescu ◽  
Adrian Doloca ◽  
Raluca Maria Vieriu ◽  
Florentina Mocanu ◽  
Gabriela Ifteni ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Fracture Pattern ◽  
Load Bearing Capacity ◽  
Cross Sectional ◽  
Load Bearing ◽  
Reinforced Composite ◽  
Polyethylene Fibre

The load-bearing capacity and fracture pattern of direct inlay-retained FRC FDPs with two different cross-sectional designs of the ponticwere tested. The aim of the study was to evaluate a new fibre disposition. Two types of composites, Filtek Bulk Fill Posterior Restorative and Filtek Z250 (3M/ESPE, St. Paul, MN, USA), and one braided polyethylene fibre, Construct (Kerr, USA) were used. The results of the study suggested that the new tested disposition of the fibres prevented in some extend the delamination of the composite on buccal and facial sides of the pontic and increased the load-bearing capacity of the bridges.

scholarly journals The energy absorption behavior of novel composite sandwich structures reinforced with trapezoidal latticed webs

2021 ◽  
Vol 60 (1) ◽  
pp. 503-518
Author(s):  
Juan Han ◽  
Lu Zhu ◽  
Hai Fang ◽  
Jian Wang ◽  
Peng Wu
Keyword(s):  
Bearing Capacity ◽  
Energy Absorption ◽  
Sandwich Structure ◽  
Ultimate Load ◽  
Sandwich Structures ◽  
Elastic Displacement ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Composite Sandwich ◽  
Composite Sandwich Structures

Abstract This article proposed an innovative composite sandwich structure reinforced with trapezoidal latticed webs with angles of 45°, 60° and 75°. Four specimens were conducted according to quasi-static compression methods to investigate the compressive behavior of the novel composite structures. The experimental results indicated that the specimen with 45° trapezoidal latticed webs showed the most excellent energy absorption ability, which was about 2.5 times of the structures with vertical latticed webs. Compared to the traditional composite sandwich structure, the elastic displacement and ultimate load-bearing capacity of the specimen with 45° trapezoidal latticed webs were increased by 624.1 and 439.8%, respectively. Numerical analysis of the composite sandwich structures was carried out by using a nonlinear explicit finite element (FE) software ANSYS/LS-DYNA. The influence of the thickness of face sheets, lattice webs and foam density on the elastic ultimate load-bearing capacity, the elastic displacement and initial stiffness was analyzed. This innovative composite bumper device for bridge pier protection against ship collision was simulated to verify its performance. The results showed that the peak impact force of the composite anti-collision device with 45° trapezoidal latticed webs would be reduced by 17.3%, and the time duration will be prolonged by about 31.1%.

scholarly journals Constructing a biomimetic robust bi-layered hydrophilic lubrication coating on surface of silicone elastomer

Friction ◽  
2021 ◽  
Author(s):  
Luyao Gao ◽  
Xiaoduo Zhao ◽  
Shuanhong Ma ◽  
Zhengfeng Ma ◽  
Meirong Cai ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Composite Layer ◽  
High Load ◽  
Silicone Elastomer ◽  
Aqueous Lubrication ◽  
Low Friction ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Lubrication Performance ◽  
Wide Range

AbstractSilicone elastomers-based materials have been extensively involved in the field of biomedical devices, while their use is extremely restricted due to the poor surface lubricity and inherent hydrophobicity. This paper describes a novel strategy for generating a robust layered soft matter lubrication coating on the surface of the polydimethylsiloxane (PDMS) silicone elastomer, by entangling thick polyzwitterionic polyelectrolyte brush of poly (sulfobetaine methacrylate) (PSBMA) into the sub-surface of the initiator-embedded stiff hydrogel coating layer of P(AAm-co-AA-co-HEMA-Br)/Fe, to achieve a unified low friction and high load-bearing properties. Meanwhile, the stiff hydrogel layer with controllable thickness is covalently anchored on the surface of PDMS by adding iron powder to provide catalytic sites through surface catalytically initiated radical polymerization (SCIRP) method and provides high load-bearing capacity, while the topmost brush/hydrogel composite layer is highly effective for aqueous lubrication. Their synergy effects are capable of attaining low friction coefficient (COFs) under wide range of loaded condition in water environment with steel ball as sliding pair. Furthermore, the influence of mechanical modulus of the stiff hydrogel layer on the lubrication performance of layered coating is investigated, for which the COF is the lowest only when the modulus of the stiff hydrogel layer well matches the PDMS substrate. Surprisingly, the COF of the modified PDMS could remain low friction (COF < 0.05) stably after encountering 50,000 sliding cycles under 10 N load. Finally, the surface wear characterizations prove the robustness of the layered lubricating coating. This work provides a new route for engineering lubricious silicon elastomer with low friction, high load-bearing capacity, and considerable durability.

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