Deterioration of Concrete Due to Combined Reaction of Carbonation and Chloride Penetration: Experimental Study

2007 ◽  
Vol 348-349 ◽  
pp. 729-732 ◽  
Author(s):  
In Seok Yoon
Keyword(s):  
Experimental Study ◽  
Boundary Conditions ◽  
Chloride Penetration ◽  
Various Boundary Conditions

In most studies, deterioration of concrete due to carbonation or chloride penetration is investigated separately. However, the deterioration of concrete is normally caused by the combination. The purpose of this study is to investigate the interaction between carbonation and chloride penetration and their effects on concrete. This was examined experimentally under various boundary conditions. For concrete under the double condition, the risk of deterioration due to carbonation was not severe. However, it was found that the carbonation of concrete could significantly accelerate chloride penetration. As a result, chloride penetration in combination with carbonation can cause harmful deterioration of concrete.

Upon Impact Numerical Modeling of Foam Materials

2017 ◽  
Vol 54 (2) ◽  
pp. 195-202
Author(s):  
Vasile Nastasescu ◽  
Silvia Marzavan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Numerical Analysis ◽  
Numerical Methods ◽  
Boundary Conditions ◽  
General Character ◽  
Foam Material ◽  
Various Boundary Conditions ◽  
Specific Behaviour

The paper presents some theoretical and practical issues, particularly useful to users of numerical methods, especially finite element method for the behaviour modelling of the foam materials. Given the characteristics of specific behaviour of the foam materials, the requirement which has to be taken into consideration is the compression, inclusive impact with bodies more rigid then a foam material, when this is used alone or in combination with other materials in the form of composite laminated with various boundary conditions. The results and conclusions presented in this paper are the results of our investigations in the field and relates to the use of LS-Dyna program, but many observations, findings and conclusions, have a general character, valid for use of any numerical analysis by FEM programs.

The Quasi-Static Analysis for Two-Dimensional Thin Plates

2011 ◽  
Vol 255-260 ◽  
pp. 166-169
Author(s):  
Li Chen ◽  
Yang Bai
Keyword(s):  
Boundary Conditions ◽  
Eigenfunction Expansion ◽  
Solution Space ◽  
Expansion Method ◽  
Fundamental Solutions ◽  
Thin Plates ◽  
Elastic Plates ◽  
Various Boundary Conditions ◽  
Eigenfunction Expansion Method ◽  
Concentration Phenomena

The eigenfunction expansion method is introduced into the numerical calculations of elastic plates. Based on the variational method, all the fundamental solutions of the governing equations are obtained directly. Using eigenfunction expansion method, various boundary conditions can be conveniently described by the combination of the eigenfunctions due to the completeness of the solution space. The coefficients of the combination are determined by the boundary conditions. In the numerical example, the stress concentration phenomena produced by the restriction of displacement conditions is discussed in detail.

Comprehensive experimental study of thermoelectric generators under transient boundary conditions

2021 ◽  
Vol 245 ◽  
pp. 114561
Author(s):  
Yeyun Cai ◽  
A. Rezania ◽  
Fang Deng ◽  
L. Rosendahl ◽  
Jie Chen
Keyword(s):  
Experimental Study ◽  
Boundary Conditions ◽  
Thermoelectric Generators

Experimental and Theoretical Nonlinear Dynamic Response of Intact and Cracked Bone-Like Specimens With Various Boundary Conditions

2007 ◽  
Vol 129 (5) ◽  
pp. 541-549 ◽  
Author(s):  
Erick Ogam ◽  
Armand Wirgin ◽  
Z. E. A. Fellah ◽  
Yongzhi Xu
Keyword(s):  
Boundary Conditions ◽  
Duffing Oscillator ◽  
Contact Friction ◽  
Nonlinear Dynamic Response ◽  
Various Boundary Conditions ◽  
Vibration Data ◽  
Element Simulation ◽  
Resonance Frequencies ◽  
Vibration Experiment ◽  
Freely Suspended

The potentiality of employing nonlinear vibrations as a method for the detection of osteoporosis in human bones is assessed. We show that if the boundary conditions (BC), relative to the connection of the specimen to its surroundings, are not taken into account, the method is apparently unable to differentiate between defects (whose detection is the purpose of the method) and nonrelevant features (related to the boundary conditions). A simple nonlinear vibration experiment is described which employs piezoelectric transducers (PZT) and two idealized long bones in the form of nominally-identical drinking glasses, one intact, but in friction contact with a support, and the second cracked, but freely-suspended in air. The nonlinear dynamics of these specimens is described by the Duffing oscillator model. The nonlinear parameters recovered from vibration data coupled to the linear phenomena of mode splitting and shifting of resonance frequencies, show that, despite the similar soft spring behavior of the two dynamic systems, a crack is distinguishable from a contact friction BC. The frequency response of the intact glass with contact friction BC is modeled using a direct steady state finite element simulation with contact friction.

Sign in / Sign up

Export Citation Format

Share Document