scholarly journals Numerical simulation of elastoplastic contact of heavy-loaded spiroid gears

2019 ◽  
Vol 287 ◽  
pp. 02005 ◽  
Author(s):  
Alexander Sannikov
Keyword(s):  
Plastic Strain ◽  
Carrying Capacity ◽  
Load Distribution ◽  
Numerical Results ◽  
Load Carrying Capacity ◽  
Contact Conditions ◽  
Elastoplastic Contact ◽  
Load Carrying ◽  
Spiroid Worm ◽  
Contact Stress Distribution

The paper presents the analysis of heavy-loaded low-speed multi-pair spiroid gears under the effect of elastic contact, bending and shearing, and elastoplastic contact interaction of spiroid gearwheel teeth and spiroid worm threads. The main stages of the developed algorithm for analysis of load distribution and plastic strain of flanks with account of elastic and elastoplastic contact conditions, multi-pair contact and macro-roughnesses on flanks are described in short. At elastoplastic contact the zones of plastic contact on flanks of spiroid gearwheel teeth are determined and the value of plastic strain is analyzed. The flanks of the spiroid gearwheel teeth and worm threads are represented in the algorithm as the set of segments (cells) with coordinates of centers determined with account of the analyzed factors that influence the load distribution in spiroid gearing. These factors are the errors of manufacturing and (or) assembly, micro-roughnesses, and deformations of spiroid gear supports. The paper gives the numerical results of research of the real spiroid gears of gearboxes for pipeline valves (PV) at elastic and elastoplastic contact represented as summary tables and diagrams of contact stress distribution along contact areas and of plastic strain, that show the workability of the algorithm. The presented numerical results of the algorithm functioning are well agreed with the experience of operation of spiroid gears and can be applied for analysis of load-carrying capacity of spiroid gears.

Validation of the Model of Elastoplastic Contact of Spiroid Gears

2020 ◽  
pp. 23-33
Author(s):  
А.М. Sannikov
Keyword(s):  
Plastic Strain ◽  
Load Distribution ◽  
Productive Efficiency ◽  
Strength Analysis ◽  
Load Carrying Capacity ◽  
Elastoplastic Contact ◽  
Strain Pattern ◽  
Initial Stage ◽  
Load Carrying ◽  
Algorithm Validation

The paper considers the problem of analyzing the elastoplastic contact of teeth in a heavy-loaded low-speed multi-pair spiroid gear. This problem is an integral part of the strength analysis that enables forecasting the load-carrying capacity of the product at the initial stage of its development. The relevance of the considered method and algorithm of calculating the load distribution and plastic strain of teeth is emphasized by its increased productive efficiency as compared to the widely used finite element method. The paper considers a common issue of validation of the developed algorithm, i.e. the correspondence of the obtained solution to the results of a real loading process. The main steps of the algorithm are given with account of the multi-pair contact and macro-roughnesses on the contact flanks that are represented as the set of areas (cells). The coordinates of the cell centers are calculated taking account of the factors influencing the load distribution in the spiroid gearing, such as manufacturing and/or assembly errors, surface micro- and macro-roughnesses, and deformations of the gearbox parts. To validate the algorithm, only one dominating factor — the gearwheel surface undulation — is chosen, since all the other factors are negligibly small. The object of the study is a gear in one of the mass-produced multi-turn spiroid gearboxes for pipeline valves. The criteria for the algorithm validation are formulated, namely, the plastic strain value, the area, shape and arrangement of the pattern of the plastic strain. By analyzing the results of numerical and experimental modeling it is possible to draw a conclusion on the validity of the results obtained by means of the studied numerical method of analysis. The divergence of the plastic strain value obtained experimentally and through calculation was under 10%, and the area of the plastic strain pattern was under 10%.

Does the Load Carrying Capacity of Third Bodies Affect Contact Conditions in Total Knee Replacement (TKR)?

1999 ◽  
Author(s):  
Markus A. Wimmer
Keyword(s):  
Carrying Capacity ◽  
Particle Number ◽  
Complete Separation ◽  
Surface Wear ◽  
Load Carrying Capacity ◽  
Third Body ◽  
Contact Conditions ◽  
Load Carrying ◽  
Total Separation ◽  
Total Knee

Abstract Third-body wear is a frequently reported phenomenon in TKR, however, little attention has been paid to the load carrying capacity of third bodies. It may be possible that these particles accumulate to a quantity, sufficient to separate the articulating surfaces of the bearing. To address this question, the particle number for a complete separation was theoretically determined and compared to realistic values. Based on the results, a total separation of the artificial knee articulation appears likely and should be considered when interpreting surface wear based on common stress analyses. This seems to be reflected by clinical observation that flat tibial components do not wear faster than dished ones.

scholarly journals Stability and Load-Carrying Capacity of Thin-Walled FRP Composite Z-Profiles under Eccentric Compression

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2956
Author(s):  
Hubert Debski ◽  
Sylwester Samborski ◽  
Patryk Rozylo ◽  
Pawel Wysmulski
Keyword(s):  
Composite Material ◽  
Carrying Capacity ◽  
Progressive Failure ◽  
Compressive Load ◽  
Experimental Tests ◽  
Numerical Results ◽  
Load Carrying Capacity ◽  
Plastic Composite ◽  
Load Carrying ◽  
Thin Walled

This study investigates the effect of eccentric compressive load on the stability, critical states and load-carrying capacity of thin-walled composite Z-profiles. Short thin-walled columns made of carbon fiber-reinforced plastic composite material fabricated by the autoclave technique are examined. In experimental tests, the thin-walled structures were compressed until a loss of their load-carrying capacity was obtained. The test parameters were measured to describe the structure’s behavior, including the phenomenon of composite material failure. The post-critical load-displacement equilibrium paths and the acoustic emission signal enabling analysis of the composite material condition during the loading process were measured. The scope of the study also included performing numerical simulations by finite element method to solve the problem of non-linear stability and to describe the phenomenon of composite material damage based on the progressive failure model. The obtained numerical results showed a good agreement with the experimental characteristics of real structures. The numerical results are compared with the experimental findings to validate the developed numerical model.

Simulating the Mechanical and Structural Properties of UltraSTEELTM Dimpled Sheet

2010 ◽  
Vol 450 ◽  
pp. 107-110 ◽  
Author(s):  
Chang J. Wang ◽  
Tarsem Sihra ◽  
Diane J. Mynors ◽  
Bac Nguyen ◽  
Martin English ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Strain ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
The Novel ◽  
Structural Components ◽  
Structural Behaviour ◽  
Steel Framing ◽  
Load Carrying ◽  
Mechanical And Structural Properties

The novel surface dimpling UltraSTEELTM process developed by Hadley Industries increases the strength of the final rolled products and enhances other product properties such as the load carrying capacity. The dimpled UltraSTEELTM sheet is used in steel framing, ceilings and other structural components. The mechanical properties and structural behaviour of the dimpled sheet are different from plain sheet due to non-uniformly distributed plastic strain and geometry of the dimples.

scholarly journals EFFECT OF SURFACE ROUGHNESS ON STEADY PERFORMANCE OF HYDROSTATIC THRUST BEARINGS: RABINOWITSCH FLUID MODEL

2019 ◽  
Author(s):  
Udaya Pratap Singh
Keyword(s):  
Surface Roughness ◽  
Carrying Capacity ◽  
Load Capacity ◽  
Numerical Results ◽  
Integral Approach ◽  
Load Carrying Capacity ◽  
Film Pressure ◽  
Thrust Bearings ◽  
Longitudinal Roughness ◽  
Load Carrying

Purpose of the present theoretical investigation is to analyze the effects of surface roughness on the steady-state performance of stepped circular hydrostatic thrust bearings lubricated with non-Newtonian Rabinowitsch type fluids. Results for film pressure and load-carrying capacity have been plotted and analyzed on the basis of numerical results. To take the effects of surface roughness into account, Christensen theory of rough surface has been adopted. The expression for pressure gradient has been derived by means of the energy integral approach. This approach avoids the derivation of Reynolds’ equation. The numerical results for film pressure and load capacity have been obtained using Mathematica. It was observed that in comparison with smooth surfaces, dimensionless film pressure and load capacity is lower for longitudinal roughness and higher for circular roughness patterns with and the variations are significant. Load carrying capacity decreases with the increase of longitudinal roughness and, increases with the increase of circular roughness. Further, the effects of surface roughness and non-Newtonian lubricants are significant for larger values of inertia parameter. Because of the closeness of results to the experimental values, this study will be helpful in the design of circular hydrostatic thrust bearings.

Performance of Balancing Wedge Action in Textured Hydrodynamic Pad Bearings

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Kazuyuki Yagi ◽  
Joichi Sugimura
Keyword(s):  
Carrying Capacity ◽  
Reynolds Equation ◽  
Central Area ◽  
Numerical Results ◽  
Load Carrying Capacity ◽  
One Dimensional ◽  
Stationary Surface ◽  
Load Carrying ◽  
Balance Solution

This study investigates a mechanism of textured features taking into account the balance of moment termed “balancing wedge action.” The principle of the suggested mechanism is that a change in moment applied to the lubricated area by incorporating textured features promotes the entire wedge action over the lubricated area. In the current study, multiple dimples are created on the stationary surface of an infinite pad bearing. A one-dimensional incompressible Reynolds equation is solved numerically to determine the load-carrying capacity of infinite pad bearings with a centrally located pivot. Numerical results show the importance of the balancing wedge action. When multiple dimples are created at the inlet side or outlet side of the lubricated area, positive load-carrying capacity is realized. When multiple dimples are located around the central area, no balance solution is obtained for the pad. The dimple depth, width, and distribution are varied to investigate the behavior of the load-carrying capacity realized by the action of the balancing wedge.

Micropolar Squeeze Films

1975 ◽  
Vol 97 (4) ◽  
pp. 635-637 ◽  
Author(s):  
M. Balaram
Keyword(s):  
Film Thickness ◽  
Carrying Capacity ◽  
Numerical Results ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Time Relationship ◽  
Load Carrying

An analysis of micropolar squeeze films is presented. Expressions are derived for calculating the pressure, the load-carrying capacity of the squeeze film and film thickness–time relationship. Numerical results computed from these expressions reveal that fluid microstructure improves the squeeze film action and increases the load-carrying capacity of the squeeze film, while the load-carrying capacity reduces rapidly with an increase in fluid substructure.

scholarly journals Numerical Investigation of FRP-Strengthened CHS Columns

2021 ◽  
Vol 20 ◽  
pp. 1-8
Author(s):  
Themistoklis Tsalkatidis
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Carrying Capacity ◽  
Steel Tube ◽  
Physical Problem ◽  
Load Carrying Capacity ◽  
Contact Conditions ◽  
Steel Columns ◽  
Load Carrying ◽  
Strengthening Method

The use of external CFRP jacket is examined as a retrofitting technique that improves the ductility and the load carrying capacity of the steel tube. The study focuses on the interaction between the steel and the jacket, which is treated as a contact problem. The contact conditions in the steel-CFRP interface are represented by interface laws. Finite element modeling is used to simulate the physical problem and the results of the numerical analysis are presented and discussed. CFRP-jacket is proved to be an effective strengthening method for hollow steel columns.

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