Determination of normal force for optimal energy dissipation of harmonic disturbance in a semi-active device

2008 ◽  
Vol 311 (3-5) ◽  
pp. 633-651 ◽  
Author(s):  
Paulin Buaka Muanke ◽  
Patrice Masson ◽  
Philippe Micheau
Keyword(s):  
Energy Dissipation ◽  
Normal Force ◽  
Active Device ◽  
Optimal Energy

Design charts for reinforced concrete L-sections

1976 ◽  
Vol 3 (4) ◽  
pp. 479-483
Author(s):  
Maher K. Tadros
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Strength ◽  
Normal Force ◽  
Basic Assumptions ◽  
Design Charts ◽  
Strength Design

The object of this paper is to present charts for the ultimate strength design of L-sections subjected to combined normal force and bending. The method of derivation of these charts is briefly described. It is general and applicable to other odd-shaped sections. It also conforms to the basic assumptions adopted in the CSA Standard A 23.3-1973. The charts can be used either for the determination of the dimensions of the section or for the check of its capacity.

scholarly journals WAVE TRANSMISSION THROUGH TRAPEZOIDAL BREAKWATERS

1978 ◽  
Vol 1 (16) ◽  
pp. 129 ◽  
Author(s):  
Ole Secher Madsen ◽  
Paisal Shusang ◽  
Sue Ann Hanson
Keyword(s):  
Energy Dissipation ◽  
Approximate Method ◽  
Cross Section ◽  
Wave Energy ◽  
Graphical Form ◽  
Dissipated Energy ◽  
Simple Method ◽  
Reflection And Transmission ◽  
Transmission Coefficients

In a previous paper Madsen and White (1977) developed an approximate method for the determination of reflection and transmission characteristics of multi-layered, porous rubble-mound breakwaters of trapezoidal cross-section. This approximate method was based on the assumption that the energy dissipation associated with the wave-structure interaction could be considered as two separate mechanisms: (1) an external, frictional dissipation on the seaward slope; (2) an internal dissipation within the porous structure. The external dissipation on the seaward slope was evaluated from the semi-theoretical analysis of energy dissipation on rough, impermeable slopes developed by Madsen and White (1975). The remaining wave energy was represented by an equivalent wave incident on a hydraulically equivalent porous breakwater of rectangular cross-section. The partitioning of the remaining wave energy among reflected, transmitted and internally dissipated energy was evaluated as described by Madsen (1974), leading to a determination of the reflection and transmission coefficients of the structure. The advantage of this previous approximate method was its ease of use. Input data requirements were limited to quantities which would either be known (water depth, wave characteristics, breakwater geometry, and stone sizes) or could be estimated (porosity) by the design engineer. This feature was achieved by the employment of empirical relationships for the parameterization of the external and internal energy dissipation mechanisms. General solutions were presented in graphical form so that calculations could proceed using no more sophisticated equipment than a hand calculator (or a slide rule). This simple method gave estimates of transmission coefficients in excellent agreement with laboratory measurements whereas its ability to predict reflection coefficients left a lot to be desired.

Fracture Toughness of PVC/NBR Blends Evaluated by the J-Integral

1993 ◽  
Vol 66 (4) ◽  
pp. 634-645
Author(s):  
N. Nakajima ◽  
J. L. Liu
Keyword(s):  
Fracture Toughness ◽  
Energy Dissipation ◽  
Crack Initiation ◽  
Crack Tip ◽  
J Integral ◽  
Integral Methods ◽  
Locus Method ◽  
Two Phases ◽  
Fracture Processes

Abstract The effect of gel on the fracture toughness of four PVC/NBR (50/50) blends was characterized by two different J- integral methods. Three of these blends are compatible blends with 33% acrylonitrile in NBRs, and the fourth with 21% acrylonitrile content, is an incompatible blend. Two types of gel are involved in this study microgels and macrogels. The J-integral methods are (1) conventional method proposed by Bagley and Landes and (2) crack initiation locus method proposed by Kim and Joe. The same load-displacement curves are used in both methods. However, the latter eliminates the energy dissipation away from the crack tip in the determination of Jc, while the former does not. Both methods produced almost the same results indicating that the energy dissipation away from the crack tip is negligible in these samples. The fracture toughness of a macrogel-containing blend is much greater than that of a microgel-containing blend, which, in turn, is only slightly greater than that of a gel-free blend. This implies that the two gel-containing blends have different fracture processes. The incompatible blend has the lowest fracture toughness due to weak interaction at the boundaries of the two phases.

scholarly journals Optimal Energy Dissipation in Sliding Friction Simulations

2012 ◽  
Vol 48 (1) ◽  
pp. 41-49 ◽  
Author(s):  
A. Benassi ◽  
A. Vanossi ◽  
G. E. Santoro ◽  
E. Tosatti
Keyword(s):  
Energy Dissipation ◽  
Sliding Friction ◽  
Optimal Energy

An Iterative Algorithm to Determine Hot Strand Pressures during Continuous Casting of Round Blooms

2011 ◽  
Vol 284-286 ◽  
pp. 1196-1204
Author(s):  
Ke Liu ◽  
Zhan Guang Han ◽  
Jia Quan Zhang
Keyword(s):  
Quantitative Analysis ◽  
Iterative Algorithm ◽  
Normal Force ◽  
Force Distribution ◽  
Cooling Zone ◽  
Secondary Cooling ◽  
Fem Model ◽  
Secondary Cooling Zone ◽  
The Given

Ovality defect of round bloom castings is the haunting defect of demanding grades steel, which can be attributed to excessive mechanical stress imposed by the roll containment especially at the unbending region. A 2-D elastic-plastic FEM model has been developed for the quantitative analysis of the effects of hot strand pressures on the ovality deformation and the contact normal force distribution. It is shown that higher friction force and smaller reduction deformation can be expected through the adoption of grooved rolls for given hot strand pressures as compared with plain rolls. For the determination of whether the given hot strand pressures can meet the requirement of strand downslide control in the caster, the resistances generated in the mold, secondary cooling zone and unbending zone are analyzed. Accordingly, an iterative algorithm has been presented to modify the hot strand pressures for given caster. A set of modified hot strand pressures has been computationally determined, which has been proved to be safe in production for casting round bloom with diameter up to Φ400mm with better roundness and less roller mark.

A Novel Thermal Model for the Piston/Cylinder Interface of Piston Machines

2009 ◽  
Author(s):  
Matteo Pelosi ◽  
Monika Ivantysynova
Keyword(s):  
Temperature Field ◽  
Energy Dissipation ◽  
Film Thickness ◽  
Elastic Deformation ◽  
Flow Model ◽  
Piston Cylinder ◽  
Gap Flow ◽  
First Time ◽  
Fully Coupled

The lubricating gaps of piston machines represent the main source of energy dissipation. The lubricating gap in these machines has to fulfill a sealing and bearing function. Therefore the prediction of the gap flow, the load carrying ability and the energy dissipation is necessary. The paper discusses a novel fully coupled model for the determination of piston/cylinder gap behavior considering the contribution of solid parts temperature induced strain. In particular, the non-isothermal gap flow model considers the squeeze film effect due to the micro-motion of the moveable parts and simultaneously the change of fluid film thickness due to the elastic deformation of the solid bodies caused by the fluid pressure field and the parts temperature field. The determination of the temperature field inside the parts, by means of detailed finite volume models, allows for the first time to accurately predict solid parts thermal expansion, which is directly affecting the gap film thickness. Therefore, the novelty of the developed fully coupled fluid-structure-thermal interaction model is the integration of a finite element solver for the determination of surface thermo-elastic deformation in a dynamic non-isothermal fluid flow model. This will allow for the first time to solve the thermo-elastohydrodynamic lubrication problem under changing load conditions, considering the impact of several different physical phenomena.

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