Estimation of the structural integrity of a runway repaired by compliant polymer concretes under thermomechanical loading conditions

2016 ◽  
Vol 140 ◽  
pp. 230-239 ◽  
Author(s):  
Kyung-Chae Jung ◽  
Seung-Hwan Chang
Keyword(s):  
Structural Integrity ◽  
Loading Conditions ◽  
Thermomechanical Loading

Simulating the thermomechanical loading conditions for ceramic parts in internal-combustion engines

1996 ◽  
Vol 28 (2) ◽  
pp. 115-120
Author(s):  
L. V. Kravchuk ◽  
K. P. Buiskikh ◽  
D. N. Ozeryanyi ◽  
S. A. Zakharov
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Loading Conditions ◽  
Thermomechanical Loading

scholarly journals Influence of Physical Parameters and Operating Conditions for Structural Integrity of Mechanical System Subjected to Squeal Noise

2013 ◽  
Vol 569-570 ◽  
pp. 1076-1084 ◽  
Author(s):  
Kevin Soobbarayen ◽  
Sébastien Besset ◽  
Jean Jacques Sinou
Keyword(s):  
Friction Coefficient ◽  
Static Loading ◽  
Structural Integrity ◽  
Operating Conditions ◽  
Brake System ◽  
Physical Parameters ◽  
Loading Conditions ◽  
Fundamental Frequencies ◽  
Loading Case ◽  
Squeal Noise

This work proposes to study the effects of physical parameters and loading conditions on both dynamic and acoustic responses of a brake system subjected to squeal. A simplified brake system model composed of a disc and a pad is investigated. The friction interface is modeled by introducing linear and non-linear stiffnesses at several local nodes to model contact. The classical Coulomb law is applied to model friction and the friction coefficient is assumed to be constant. A stability analysis of this system is performed with respect to the friction coefficient and the hydraulic brake pressure. Then self-excited vibrations are investigated for two cases of loading conditions: static loading and ramp loading. Time responses for these cases are significantly different: the case with ramp loading presents higher amplitude of velocity than the static loading case. For the case with ramp loading, the spectrum analysis performed by the Continuous Wavelet Transform, shows the appearance of the fundamental frequencies of unstable modes but also their harmonics and combinations frequencies. Sound pressures radiated during squeal event present different peculiar patterns of directivity for both cases and for a progressive load, the levels are significantly higher.

Deformation Modeling and Lifetime Prediction of Ni-Base Gas Turbine Blade Alloys Under TMF-Conditions

2014 ◽  
Author(s):  
Stefan Grützner ◽  
Bernard Fedelich ◽  
Birgit Rehmer ◽  
Maria Mosquera
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Creep Damage ◽  
Material Model ◽  
Lifetime Prediction ◽  
Strain Accumulation ◽  
Loading Conditions ◽  
Gas Turbine Blade ◽  
Thermomechanical Loading ◽  
Cyclic Thermomechanical Loading

Under cyclic thermomechanical loading conditions, various effects such as strain accumulation, creep damage, ageing, fatigue etc. may occur in the material of a gas turbine blade. Depending on the loading conditions, all these effects contribute to reduce the lifetime of the component. Subject of the present work is the development of a lifetime model able to discriminate between the different damage mechanisms, as well as the development of a material model to describe the mentioned effects and thus providing the input data for lifetime prediction.

scholarly journals Special Issue on Fracture and Fatigue Assessments of Structural Components

2020 ◽  
Vol 10 (18) ◽  
pp. 6327
Author(s):  
Alberto Campagnolo
Keyword(s):  
Fatigue Life ◽  
Structural Integrity ◽  
Fatigue Loading ◽  
Complex Geometries ◽  
Loading Conditions ◽  
Structural Elements ◽  
Structural Components ◽  
Special Issue ◽  
Linear Elastic ◽  
Life Predictions

This Special Issue covers the broad topic of structural integrity of components subjected to either static or fatigue loading conditions, and it is concerned with the modelling, assessment and reliability of components of any scale. Dealing with fracture and fatigue assessments of structural elements, different approaches are available in the literature. They are usually divided into three subgroups: stress-based, strain-based and energy-based criteria. Typical applications include materials exhibiting either linear-elastic or elasto-plastic behaviours, and plain and notched or cracked components subjected to static or cyclic loading conditions. In particular, the articles contained in this issue concentrate on the mechanics of fracture and fatigue in relation to structural elements from nano- to full-scale and on the applications of advanced approaches for fracture and fatigue life predictions under complex geometries or loading conditions.

Material Modelling and Lifetime Prediction of Ni-Base Gas Turbine Blades under TMF Conditions

2014 ◽  
Vol 891-892 ◽  
pp. 1277-1282 ◽  
Author(s):  
Stefan Gruetzner ◽  
Bernard Fedelich ◽  
Birgit Rehmer ◽  
Bjoern Buchholz
Keyword(s):  
Gas Turbine ◽  
Turbine Blades ◽  
Material Model ◽  
Loading Conditions ◽  
Thermomechanical Loading ◽  
Damage Mechanisms ◽  
Surface Cracking ◽  
Gas Turbine Blades ◽  
Creep Cavitation ◽  
Cyclic Thermomechanical Loading

Under cyclic thermomechanical loading conditions, various damage mechanisms such as strain accumulation, creep cavitation, ageing, fatigue surface cracking etc. may take place in the material of a gas turbine blade. Depending on the loading conditions, all these effects can contribute to reduce the lifetime of the component. Subject of the present work is the development of a material model to describe the mechanical effects mentioned above, as well as the development of a lifetime model able to discriminate the different damage mechanisms.

Nonlinear stability of CNT-reinforced composite cylindrical panels with elastically restrained straight edges under combined thermomechanical loading conditions

2018 ◽  
Vol 33 (2) ◽  
pp. 153-179 ◽  
Author(s):  
Le Thi Nhu Trang ◽  
Hoang Van Tung
Keyword(s):  
Nonlinear Stability ◽  
Shear Deformation Theory ◽  
Initial Imperfection ◽  
Functionally Graded ◽  
Combined Loading ◽  
Loading Conditions ◽  
Thermomechanical Loading ◽  
Elastic Foundations ◽  
Reinforced Composite ◽  
Cylindrical Panels

This article investigates the nonlinear stability of composite cylindrical panels (CPs) reinforced by carbon nanotubes (CNTs), resting on elastic foundations and subjected to combined thermomechanical loading conditions. CNTs are embedded into matrix phase through uniform distribution or functionally graded distribution. Material properties of constituents are assumed to be temperature dependent and effective elastic moduli of carbon nanotube–reinforced composite are estimated by the extended rule of mixture. Nonlinear governing equations of geometrically imperfect panels are based on first-order shear deformation theory accounting for elastic foundations and tangential constraint of straight edges. Analytical solutions are assumed to satisfy simply supported boundary conditions and closed-form expressions relating load and deflection are derived through Galerkin method. Numerical examples show the effects of preexisting nondestabilizing loads, distribution patterns, panel curvature, in-plane condition of unloaded edges, thermal environments, initial imperfection, and elastic foundations on the nonlinear stability of nanocomposite CPs under combined loading conditions.

Bend Stiffener Design for Umbilicals

2011 ◽  
Author(s):  
Nils So̸dahl ◽  
Torfinn Ottesen
Keyword(s):  
Structural Integrity ◽  
Fatigue Loading ◽  
General Description ◽  
Loading Conditions ◽  
Optimization Scheme ◽  
Capacity Curve ◽  
Relative Angle ◽  
Compliant Structure ◽  
Extreme Load ◽  
Design Loads

A crucial design issue for compliant risers and umbilicals for dynamic applications is termination of the compliant structure to a rigid structure. A practical way to solve this problem is to introduce a properly designed bend stiffener to limit the stresses in the compliant structure due to bending at the supports. The bend stiffener provides a gradually increase of the bending stiffness from the rather small value of the compliant structure to a significantly larger value that can be rigidly connected without compromising the structural integrity of the compliant structure. Hence, the bend stiffener geometry needs to be designed to fulfill the design requirements for extreme as well as fatigue loading conditions for the compliant structure. Furthermore, it is required that the bend stiffener is as short as possible to limit costs, support forces, and enable fabrication and installation. The main focus of this paper is to outline an optimization scheme for bend stiffeners to meet design criteria for extreme loading conditions. Measures to provide an adequate fatigue performance of bend stiffeners are also discussed. The loads on the bend stiffener are governed by effective tension and relative angle close to the support (i.e. direction of effective tension relative to the longitudinal direction of the compliant structure at the support). Combinations of effective tension and relative angle aggregated for all relevant extreme load conditions define the design loads on the bend stiffener. The capacity of the compliant structure is governed by a capacity curve expressing the allowable curvature as function of the effective tension. A general optimization scheme is outlined accounting for a general description of the design loads as well as the capacity curve. The optimization methodology is based on a general purpose optimization algorithm utilizing a tailor made non-linear static finite element solver to describe the response of the bend stiffener and the compliant structure. Non-dimensional design curves are also presented based on a simplified conservative description of the design loads and the capacity. This allows for easy practical sizing of bend stiffeners without the need for sophisticated optimization software.

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