An Optimum Short Bearing Theory for the Elastohydrodynamic Solution of Journal Bearings

1986 ◽  
Vol 108 (2) ◽  
pp. 294-298 ◽  
Author(s):  
P. K. Goenka ◽  
K. P. Oh
Keyword(s):  
Finite Difference Methods ◽  
Computation Time ◽  
Axial Direction ◽  
Approximate Solutions ◽  
Connecting Rod ◽  
Governing Equations ◽  
Ehd Lubrication ◽  
Separation Of Variable ◽  
Raphson Method ◽  
Murty's Algorithm

An approximate method for solving the elastohydrodynamic (EHD) lubrication problem has been developed. The method is based on two assumptions: the separation of variable for pressure and a parabolic pressure distribution in the axial direction. To solve the governing equations, the Newton-Raphson method, in conjunction with Murty’s algorithm, is used. The finite-element and the finite-difference methods are then used to obtain approximate solutions. The rod bearing of a typical connecting rod is analyzed by the new method. The results are compared to the full EHD solution and the rigid bearing solution. Significant reduction in computation time is realized when compared to the full EHD solution.

EHD Analysis, Including Structural Inertia Effects and a Mass-Conserving Cavitation Model

1995 ◽  
Vol 117 (3) ◽  
pp. 540-547 ◽  
Author(s):  
D. Bonneau ◽  
D. Guines ◽  
J. Freˆne ◽  
J. Toplosky
Keyword(s):  
General Motors ◽  
Connecting Rod ◽  
Cavitation Model ◽  
Inertia Effects ◽  
Structural Inertia ◽  
Newton Raphson ◽  
Inertia Forces ◽  
Raphson Method ◽  
Murty's Algorithm ◽  
Isoparametric Elements

The dynamic behavior of two elastic connecting-rod bearings is studied. The Newton-Raphson method and 8-node isoparametric elements for the lubrication analysis are used. For the structural analysis, 3-D elasticity assumptions are made and 20 nodes isoparametric elements are used. Inertia forces due to the kinematics of the structure are incorporated with the effects of the hydrodynamic pressures in the elastic deformations of the bearing. Comparisons with Goenka‘s results are presented for the General Motors connecting-rod bearing. A mass-conserving model used in conjunction with Murty‘s algorithm is presented for the transient evolution of the cavitation area. This model is applied for the EHD study of a Renault connecting-rod bearing.

Finite Element Analysis of Dynamically Loaded Journal Bearings: Influence of the Bolt Preload

2002 ◽  
Vol 124 (3) ◽  
pp. 486-493 ◽  
Author(s):  
Fabrizio A. Stefani ◽  
Alessandro U. Rebora
Keyword(s):  
Combustion Process ◽  
Elastic Behavior ◽  
Connecting Rod ◽  
Element Analysis ◽  
Fem Model ◽  
Bolt Preload ◽  
Marine Diesel ◽  
Newton Raphson ◽  
Raphson Method ◽  
Murty's Algorithm

An improved FEM model was developed to simulate the elastic behavior of a connecting rod bearing, accounting for the displacements caused by the tightening torque applied to the bolts that join the cap and the rod. These initial displacements are added to the pressure induced displacements, to enhance the solution of the elastohydrodynamic bearing lubrication problem. The big end bearing of a marine diesel engine was modeled and analyzed under combustion process loads and inertia loads using the Newton-Raphson method together with the Murty’s algorithm. Some important differences between these results and other results published for the same bearing without the bolt preload are identified and discussed.

Optimization of a Snap Through Spring for a Hydraulic Valve With Hysteresis Response Behavior

2019 ◽  
Author(s):  
Matthias Scherrer ◽  
Rudolf Scheidl ◽  
Bernhard Manhartsgruber
Keyword(s):  
Ritz Method ◽  
High Strength ◽  
Axial Direction ◽  
Approximate Solutions ◽  
Element Model ◽  
Lateral Force ◽  
Spring Steel ◽  
Nonlinear Buckling ◽  
Buckling Beam ◽  
Compact Design

Abstract The hydraulic binary counter requires switching valves with a hysteretic response. In this paper an elastic snap through element is studied as means for that. The concept is based on a buckling beam which is elastically supported in axial direction in order to adjust its buckling properties with moderate manufacturing precision and to assure a well defined snap through behavior. The elastic support is provided by a cantilever beam. A rigorous optimization is performed heading for a most compact and fatigue durable design which exhibits the required lateral force displacement characteristics. A genetic algorithm is used to find the global design optimum. The stress/displacement properties of each design variant are computed by a compact model of the snap through system. It is derived by a Ritz method to obtain approximate solutions of the nonlinear buckling beam behavior. Its validity is checked by a Finite Element model. A compact design is possible if high strength spring steel is used for the elastic elements.

EHD Lubrication of Multi-Body Common-Pin Conrod Big End Bearings System

2007 ◽  
Author(s):  
Aurelian Fatu ◽  
Dominique Bonneau
Keyword(s):  
Reynolds Equation ◽  
Film History ◽  
Mass Conservation ◽  
Connecting Rod ◽  
Thrust Bearings ◽  
Ehd Lubrication ◽  
Cylindrical Coordinate ◽  
Real Behavior ◽  
Multi Body ◽  
Fully Coupled

This paper describes a model for the analysis of elastohydrodynamic (EHD) lubrication of a multi-body common-pin connecting-rod (conrod) big end bearing system. Two conrod and three thrust bearings are fully coupled in order to simulate real behavior of the system. An extended Reynolds equation including mass conservation and oil film history is solved in the big end conrod bearings. The HD behavior of the thrust bearings is simulated by a cylindrical coordinate Reynolds equation. By comparisons with classical single rod analysis results show the pertinancy of simulating twin moving conrods.

Simulation of EHD Lubrication of Common-Pin Conrod Big End Bearings in High Speed IC Engines

2005 ◽  
Author(s):  
Ming-Tang Ma ◽  
Bernhard Loibnegger
Keyword(s):  
High Speed ◽  
Internal Combustion ◽  
Inertial Effect ◽  
Body System ◽  
Connecting Rod ◽  
Tribological Behaviour ◽  
Ehd Lubrication ◽  
Ic Engines ◽  
Multi Body

This paper describes a methodology for the analysis of elastohydrodynamics (EHD) of connecting-rod (conrod) big end bearings in high-speed internal combustion (IC) engines. In addition to the elasticity of the conrod structure and crankpin, the dynamic and inertial effect of conrod motion on the bearing tribological behaviour is considered realistically based on a multi-body system (MBS) approach. Results show that it is necessary to simulate two big end bearings of common-pin simultaneously with the inclusion of a complete crankthrow in the MBS model.

NEW ANALYTICAL METHOD OF DISPERSION CURVES IN PLANE LAYERED STRUCTURES

2012 ◽  
Vol 20 (03) ◽  
pp. 1250010 ◽  
Author(s):  
C. PACHIU ◽  
H. FRANKLIN ◽  
J.-L. IZBICKI
Keyword(s):  
Computation Time ◽  
Layered Structures ◽  
Dispersion Curves ◽  
Wave Number ◽  
Dual Representation ◽  
Reflection And Transmission ◽  
The Real ◽  
Transmission Coefficients ◽  
Layer Structures ◽  
Raphson Method

The propagation of sound through plane layered structures is considered, with emphasis on three-layers made up of thick isotropic plates coupled with a thin anisotropic one. Modes are obtained by means of the transition terms method (TTM) based upon the use of the reflection and transmission coefficients. This method differs from the root searching methods (RSM) of dispersion equations such as, for instance, the Newton–Raphson method. The TTM provides dispersion curves with very little computation time. It unifies the dual representation of the dispersion curves: either complex wave numbers versus the real frequency, or complex frequencies versus the real wave number. The application to various cases of three-layer structures allows us to check the validity of the method and to discuss the connection between the TTM and Cremer's correspondence principle.

Finite Element Mass-Conserving Cavitation Algorithm in Pure Squeeze Motion. Validation/Application to a Connecting- Rod Small End Bearing

1999 ◽  
Vol 122 (1) ◽  
pp. 162-169 ◽  
Author(s):  
Virgil Optasanu ◽  
Dominique Bonneau
Keyword(s):  
Finite Element ◽  
Analytical Approach ◽  
Numerical Results ◽  
Oscillatory Motion ◽  
Finite Element Code ◽  
Connecting Rod ◽  
Ehd Lubrication ◽  
Boundary Position

A simple analytical approach using conditions of conservation of the mass is proposed for the 1-D “negative squeeze” lubrication problem in order to calculate the cavitation boundary position during oscillatory motion of two plates. The same geometrical case is analyzed using Bonneau’s finite element code. Good agreements between analytical and numerical results support validation of Bonneau’s algorithm. As an example of application of this algorithm to squeeze motion case, the EHD lubrication of an elastic connecting-rod small end bearing is analyzed. Influences of the shaft elasticity and lubricant piezoviscosity are presented. [S0742-4787(00)02101-9]

An Efficient Simulation Method for Distributed Lumped Fluid Networks

1977 ◽  
Vol 99 (1) ◽  
pp. 34-40 ◽  
Author(s):  
R. S. Sidell ◽  
D. N. Wormley
Keyword(s):  
Finite Difference Methods ◽  
Computation Time ◽  
Simulation Method ◽  
Transmission Network ◽  
Efficient Simulation ◽  
Fluid Networks ◽  
Lumped Elements ◽  
Simulation Results ◽  
Core Storage ◽  
Nonlinear Resistance

A method is presented for the simulation of fluid networks consisting of uniform distributed elements and lumped dynamic, nonlinear elements. The uniform transmission elements may be lossy and dispersive. General relationships are derived for their terminations in junctions with other elements and/or with dynamic, nonlinear lumped elements. The basic computer simulation method is efficient in terms of computation time and core storage requirements in comparison to direct finite difference methods and may be implemented on a minicomputer. Simulation results are compared with experimental data for a pneumatic transmission line terminated with a nonlinear resistance and for a pneumatic transmission network consisting of three lines of incommensurate lengths.

AN IMPROVED REDUCTION METHOD FOR THE ROBUST OPTIMIZATION OF THE ASSIGNMENT PROBLEM

2012 ◽  
Vol 29 (05) ◽  
pp. 1250032 ◽  
Author(s):  
BYUNGJUN YOU ◽  
DAISUKE YOKOYA ◽  
TAKEO YAMADA
Keyword(s):  
Lower Bound ◽  
Exact Solutions ◽  
Upper Bound ◽  
Assignment Problem ◽  
Numerical Experiments ◽  
Reduction Method ◽  
Computation Time ◽  
Approximate Solutions ◽  
Cpu Time ◽  
Surrogate Relaxation

We are concerned with a variation of the assignment problem, where the assignment costs differ under different scenarios. We give a surrogate relaxation approach to derive a lower bound and an upper bound quickly, and show that the pegging test known for zero–one programming problems is also applicable to this problem. Next, we discuss how the computation time for pegging can be shortened by taking the special structure of the assignment problem into account. Finally, through numerical experiments we show that the developed method finds exact solutions for instances with small number of scenarios in relatively small CPU time, and good approximate solutions in case of many scenarios.

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